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EMC Testing brochure


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  • 1. The Engineer’s Guide To Global EMC Requirements: 2007 Edition Written by: Roland Gubisch, Chief EMC Engineer and Bill Holz, GMAP Program Manager, Intertek Intertek Testing Services NA, Inc 70 Codman Hill Road, Boxborough, MA 01719 800-WORLDLAB
  • 2. Engineer’s Guide to Global EMC RequirementsTable of ContentsIntroduction……………………….……………………………………….2Background………………………………………………………………..2EMC as a mandatory compliance requirement………………………....3Regulatory compliance procedures………………………..……………..4Regulatory compliance frameworks……………………………………...4Authority Having Jurisdiction over EMC………………………………….6 Americas…………………………….……………………………..6 US………………………………………………………….7 Canada……………………………………………………8 Brazil………………………………………………………9 Europe……………………………….……………………………10 EU…………………………….…………………………..10 Russia……………………………………..………………11 Far East…………………………………………………………….12 Japan………………………………………………………12 China (PRC)……………….………………………..……..14 Chinese Taipei…………….……………………………....15 Conclusion………………..……………………………………… 1
  • 3. Engineer’s Guide to Global EMC RequirementsIntroductionEngineers everywhere would like to test their products only once for electromagneticcompatibility (EMC), using a single set of standards and placing a single mark on theproducts to allow them to be sold around the world. Unfortunately, that aspiration will notbecome reality any time soon. If anything, it is becoming even more elusive as companiespursue new global sales opportunities further afield. The challenges are no longer technical;increasingly, they are raised by regulators in government offices many time zones away.The task of EMC testing for global markets is challenging indeed. Each country or regionretains its right to determine: • If EMC is a mandatory compliance aspect that must be met prior to placing products on the market • Identification of the authority that will have jurisdiction over regulating EMC • Determination of the technical requirements that must be met - whether emissions only (EMI), or both emissions and immunity (EMC) • Identification of the standards required • Compliance procedures and filings • Determination of what test reports will be accepted • Specification of any marks that must be applied.This paper will review the regulatory issues of EMC compliance in selected regions aroundthe world.BackgroundEMC issues have been around since the early days of telegraphy and radio. Interferencefrom solar activity caused “phantom telegraph operators” – telegraph output with notelegraph input – on long parallel transmission wires. The cure for this condition wasoccasional twists in the wires, which led directly to today’s high-speed twisted-pair LANwiring.With the increasing popularity of broadcasting, and then with the use of electronicequipment in commercial and military applications, rules to prevent radio interference andequipment malfunctions became necessary. The result has been a succession of EMCstandards and regulatory procedures worldwide. Some of the milestones are: 1844 Morse: telegraph 1892 Law of telegraph in Germany (EMC) 1895 Marconi: first radio transmission 1927 German Hochfrequenzgerätegesetz (High frequency device laws) 1933 CISPR founded as a special committee of the IEC, dealing with 2
  • 4. Engineer’s Guide to Global EMC Requirements 1934 US Communications Act; FCC is established 1972 Altair 8800: first personal computer (PC) 1979 FCC Part 15, subpart J (digital devices) 1985 IEC CISPR 22 (Information Technology Equipment - ITE) 1989 EMC Directive, EU; mandatory 1-1-1996.Personal computers and other microprocessor-based devices have triggered similaremissions standards around the world: 1979 FCC Part 15, subpart J 1985 IEC CISPR 22 1985 VCCI rules in Japan 1988 Canada Radio Act 1996 Australian EMC Framework 1997 Taiwan ITE EMI 1998 Korea ITE EMC 2000 Singapore EMI for telecom equipmentEMC as a mandatory compliance requirementThe first task is to identify the countries in which your company’s products are to be sold.Then you need to determine what EMC compliance requirements (if any) must be metbefore the products can be marketed in those countries.The overall scope of your efforts will be determined by the number of countries in whichyou wish to sell your products, of course. However, to keep this paper manageable – whileproviding a flavor of the issues to be encountered - we will limit the list to the followingregions: Americas: • United States (US) • Canada • Brazil Europe • European Union (EU) • Russia Far East • Japan • Chinese Taipei (Taiwan) • People’s Republic of China.Let’s assume that with all of its products, your company always carries out complete EMCtesting for the US and EU. Is that enough to allow you to place products everywhere in 3
  • 5. Engineer’s Guide to Global EMC Requirementsworld? Unfortunately, it is not. Many countries that require EMC compliance also imposeadditional hurdles to market entry in terms of deviations to international standards, in-country testing or country presence. Fortunately, there are also simplifying arrangementsand agreements that can leverage your EMC testing to cover larger geographical or marketareas. They are found under the broad umbrella term MRA (Mutual RecognitionAgreements or Arrangements).Regulatory compliance proceduresCountries or regions that regulate product EMC will typically employ one or more of threeprocedures to determine compliance with national or regional requirements. The particularprocedure may depend on product type. • Verification – the product is tested to the applicable EMC standard(s) and brought to market bearing appropriate regulatory marks and/or statements under the vendor’s or importer’s authority (the “responsible party”). • Declaration of Conformity – the vendor or other responsible party declares conformity of the product to the relevant standard(s). Some jurisdictions require accredited testing (US) while others do not. The product may then need to be registered with the regulator (Australia, for example) or not (US for EMC). Regulatory marking and user information are a part of the process. • Certification - the test report from an accredited or recognized laboratory, along with other technical information about the product, is presented to an independent third party for examination against the requirements. If the product complies, it is certified and listed with the regulator. The product may bear the certifier’s mark. Product surveillance may also be a part of the certification process.It’s not always easy for the regulatory compliance engineer or manager to determine theapplicable standards, compliance procedures and contact information for each targetcountry or region. Fortunately, there are simplifying frameworks to lighten the burden .Regulatory compliance frameworksMutual Recognition Agreements or Arrangements (MRAs) are multilateral agreementsamong countries or regions which facilitate market access for signatory members. MRAscan cover the mutual recognition of product testing, certification or both.However, the existence of an MRA does not imply harmonization of the standards amongthe participants. For example, the interpretation of appropriate Class A or Class B emissionlimits in a commercial environment can differ between the US and the EU, as reflected intheir respective standards and illustrated 4
  • 6. Engineer’s Guide to Global EMC RequirementsSome of the terms common to existing MRAs include: Agreement: Binding on participating parties Arrangement: Voluntary participation CAB: Conformity Assessment Body. A CAB can be either a tester or a certifier or both. In the case of US Telecommunication Certified Bodies (TCBs) and Canadian Certification Bodies, the certifier must also be an accredited test lab. The accreditation criterion for testers is ISO 17025 and for certifiers it is ISO Guide 65. Phase I: The MRA partners agree to recognize each other’s test reports Phase II: The MRA partners agree to recognize each other’s test reports and certifications (where needed).One of the better-known MRAs is the agreement between the European Union and the UScovering EMC, radio, telecom and several other product sectors. It has become a model forsubsequent MRAs. Other MRAs in operation or pending that cover EMC and telecominclude: Canada: With EU In APEC Tel In CITEL With Switzerland With Korea US: With EU With EEA EFTA (Iceland, Norway, Liechtenstein) With Japan In APEC Tel In 5
  • 7. Engineer’s Guide to Global EMC Requirements European Union: With US With Canada With Australia With New Zealand.Participating members of CITEL include Argentina, Brazil, Dominican Republic, Guatemala,Ecuador, Honduras, Mexico, and Paraguay. Participants in the APEC Tel MRA includeAustralia, Canada, Chinese Taipei (BSMI), Chinese Taipei (NCC, formerly DGT), Singapore,Korea, and Hong Kong.MRAs are allowing testing and certification by CABs in one region or country to beaccepted in another region or country − facilitating market access without additional testing.Regarding EMC, this is especially important when the destination country requirescertification as a regulatory requirement.Authority Having Jurisdiction over EMCAs you investigate each country to determine which agency has the EMC authority for yourproducts, you should also be able to determine what those requirements are. Around theworld, RF emissions or EMI is regarded as a potential threat to broadcast reception and tosensitive services such as radio navigation and radio astronomy. Therefore the spectrum orradio regulator in each country or region is usually charged with the widest responsibilityfor controlling EMI. Immunity, on the other hand, may be reserved as a performance issuefor critical applications such as medical or military – and the regulator may differ in eachcase. The combination of EMI and immunity as EMC may also be used as a means toestablish uniform trade rules across a region, as it is in the EU. The following is a briefoverview of what you need to consider as you investigate the requirements for eachcountry. We will use the US as a detailed example.AMERICASUS • The Federal Communications Commission (FCC) establishes the compliance regulations for radios, digital devices and other unintentional radiators. It does not regulate immunity, except in a few special cases. Typical emissions standards are Parts 15 (RF devices) and 18 (ISM equipment). Some applications of digital devices are exempted from the FCC’s technical standards, as is the case with test equipment, transportation vehicles, appliances, utilities or industrial plants. In many cases, such exempted equipment comes under the jurisdiction of other authorities, as noted below. Approval procedures: Verification for most unintentional radiators. No lab accreditation required. Some devices require Declaration of Conformity (DoC) and testing by an accredited lab in the US or MRA partner country. Some 6
  • 8. Engineer’s Guide to Global EMC Requirements radiators may be optionally certified by TCBs. For certification testing, the lab must be accredited and listed with the FCC either separately or through an accreditor. • The Food and Drug Administration (FDA) Center for Devices and Radiological Health (CDRH), designates consensus device standards for medical devices. Typical EMC standards include: IEC 60601-1-2:2001+A1:2004 (general medical EMC); FDA MDS- 201-0004 (1979) (EMC for medical devices); and ANSI / RESNA WC/Vol. 2-1998, Section 21, (Requirements and test methods for electromagnetic compatibility of powered wheelchairs and motorized scooters). Approval procedures: EMC report is submitted as part of device 510(k) filing, to FDA or an FDA-accredited person. • Department of Defense (DoD), for military EMC. A common EMC standard is MIL- STD-461E (1999) Requirements for the control of electromagnetic interference; characteristics of subsystems and equipment. Approval procedure: EMC testing can be witnessed by DoD inspector; lab accreditation is helpful. • Telecom network EMC varies by telecom network operator (ATT, Verizon, etc.), but most EMC requirements are based on GR-1089-CORE (2002) Electromagnetic compatibility and electrical safety – generic criteria for network telecommunications equipment. Approval procedure: EMC accreditation to GR-1089-CORE sections 2-4; network operator witnesses or accredits; equipment vendor submits test report to network operator. • RTCA, for aircraft and equipment EMC. The standard RTCA DO160D Environmental conditions and test procedures for airborne equipment includes both EMC and environmental requirements. This standard is harmonized with the European EUROCAE ED-14D. Approval procedure: EMC report is submitted to FAA (Federal Aviation Authority); lab accreditation is helpful. • SAE (Society of Automotive Engineers) EMC standard series J551/x, J1113/x is a start. However, the individual auto manufacturers (Ford, GM, DaimlerChrysler, Toyota, etc.) have their own EMC standards that differ from the SAE’s standards. Approval procedure: EMC report is submitted by device vendor to auto manufacturer; lab accreditation is important.This presents a fairly complex picture of regulations and regulatory authorities for EMC inthe US. The table below summarizes some of this EMC information in a convenient formatfor comparison with other jurisdictions.Jurisdiction United States - 7
  • 9. Engineer’s Guide to Global EMC RequirementsProduct type ITE Radio Appliance MedicalAuthority FCC FCC FCC exempt FDA/CDRH EMI only:Approval Verification Certification N/A CertificationProcedures DoC: accredited Cert: accreditedIn-countrytesting No No N/A Norequired?MRA with N/A N/A N/A N/AUS? For DoC only:Marks None N/A N/A FCC logoCanada • The regulation of EMC in Canada is similar to that in the US. Industry Canada (IC) establishes the compliance regulations for radios, digital devices and other unintentional radiators. Typical emissions standards are ICES-003 (ITE) and ICES-001 (ISM equipment). Some applications of digital devices are exempted from IC technical standards, in a manner similar to the FCC. In many cases, such exempted equipment falls under the jurisdiction of other authorities, as noted below. Approval procedures: Verification for all unintentional radiators. No lab accreditation required. • Health Canada (HC) designates consensus device standards for medical devices. It recognizes IEC 60601-1-2:2001+A1:2004 (general medical EMC). Approval procedures: EMC report is submitted as part of license application to HC. Class I device manufacturers require an establishment license; Class II, III and IV devices require a medical device license.Jurisdiction Canada - EMCProduct type ITE Radio Appliance MedicalAuthority Industry Canada Industry Canada IC exempt Health CanadaApproval EMI only: Certification N/A LicensingProcedures VerificationIn-countrytesting No No N/A Norequired?MRA with Yes, Phase I Yes, Phases I & II N/A 8
  • 10. Engineer’s Guide to Global EMC RequirementsUS?Marks Label info only Label info only N/A N/A Brazil • The National Institute of Metrology, Standardization and Industrial Quality (INMETRO) is the authority with jurisdiction over the general safety of products as well as EMC. There are very few general products that require safety for INMETRO certification and none that require EMC at this time. • Radio and telecom products are certified and homologated (an administrative approval) by the National Telecom Agency (ANATEL) and EMC is a factor in the approval. Both emissions and immunity compliance are required for telecom equipment; the standards reference IEC. Many but not all of the rules for short- range radio devices are identical to FCC rules. • The National Health Surveillance Agency (ANVISA) is the authority for medical equipment; EMC is also required.Jurisdiction Brazil - EMCProduct type ITE Radio Appliance MedicalAuthority INMETRO ANATEL INMETRO ANVISAApproval Certification and N/A N/A RegistrationProcedures HomologationIn-countrytesting N/A Yes N/A Norequired?MRA with Pending Pending N/A N/AUS?Marks no no N/A N/AEUROPEEUWith 27 member states, the population and economy of the EU exceeds that of the US. TheEU has simplified the process of access considerably by identifying the “essentialrequirements” for almost everything that is placed on the market in the EU. The authoritieshaving jurisdiction vary by product type, and each country has a Competent Authority foreach product type or directive. For example, the Competent Authority for EMC in the UK isthe Department of Trade and Industry (DTI). The specific “essential requirements” for yourproducts will be listed in the directives that apply to your product. In most cases, 9
  • 11. Engineer’s Guide to Global EMC Requirementsdirectives will be “New Approach” directives for which CE marking signifies compliance andthe applicable standards have been published in the Official Journal of the European Union.A good place to start for guidance on directives and standards is The CE marking indicates that the equipment bearing themarking complies with all of the applicable “New Approach” directives. • Most electrical/electronic products must comply with both emission and immunity requirements, according to both the current EMC Directive 89/336/EC and the new EMC Directive replacing it, 2004/108/EC. This includes appliances and many devices exempted from EMI regulation in the US and Canada. In addition, the safety standards for household appliances now require compliance with limits to the surrounding low-frequency electromagnetic fields according to EN 50366. This is a safety standard, not an EMC standard. • The “essential requirements” for radio and telecom equipment under the R&TTE Directive 1999/5/EC include electrical safety according to the Low Voltage Directive (but with no lower voltage limit), RF exposure for radio transmitters and EMC according to the EMC Directive. For telecom terminal equipment, there are no more requirements. Radio transmitters must also comply with requirements for efficient use of the spectrum. Both spectrum and EMC standards for radio equipment are published by ETSI, the European Telecommunications Standards Institute. • Medical devices are approved according to a classification scheme originating with the Medical Device Directive 93/42/EC and used as the prototype for other medical device regulations around the world, including Canada. The basic medical EMC standard is EN 60601-1-2:2001. The EMC requirements are modified by specific standards EN 60601-2-x to define particular test setups or higher or lower limits for particular EMC phenomena. EMC is also a factor for in vitro diagnostic medical devices (Directive 98/79/EC) and active implantable medical devices (Directive 90/385/EEC).Jurisdiction European Union – EMCProduct type ITE Radio Appliance Medical Spectrum EMC Medical EMC CompetentAuthority Competent Competent Competent Authority Authority Authority Authority Verification, Verification. Verification. DoC, TypeApproval Notified Body Notified Body Verification Examination,Procedures opinion may be opinion may be Notified Body obtained rendered. approvalIn-country No No No 10
  • 12. Engineer’s Guide to Global EMC Requirementsrequired?MRA with Yes, Phases I & II Yes, Phases I & II Yes, Phases I & II Yes, Phases I & IIUS? CE, possibly CE and Notified Notified BodyMarks CE CE Body number number, alert where applicable markRussia • The authority having jurisdiction for general product types is GOST, short for Gosstandart (State Committee for Quality Control and Standardization). It is the national standardization body in Russia. More then 60 EMC standards have become mandatory. Basic standards are harmonized with IEC and CISPR standards. The Harmonized Tariff Code (HTC) is the determining factor if EMC applies to your products. If your product requires EMC compliance, testing can be done in Russia or at accredited labs located outside of Russia. It is also possible (based on agreements) to utilize EMC test reports to the EU standards from accredited labs. If your product requires the GOST mark, both safety and EMC are included under the single mark. You will also need to determine whether any special warning statements need to be included in the user manual and on the packaging, along with any specific language requirements. • The authority for radio equipment in Russia is Glavgossvyaznadzor (Main Inspectorate in Communications). The application (with a detailed list of telecommunications equipment) should be submitted to the Certification Department of Goskomsvyaz (State Committee on Telecommunications and Information of the Russian Federation). The Department carries out a preliminary analysis to determine whether the equipment is compatible with the telecommunications technology currently used in Russia. After this technical review, two designated certification laboratories (of the 43 located across the country) will test the equipment "on type" and also for quality assurance. This will involve testing in the field and at the manufacturers site. If the test results are successful, a Goskomsvyaz Certificate is issued and is valid for up to three years. Radio equipment sellers must obtain an additional permit from Gossvyaznadzor (The Russian Federation State Telecommunications Control) of the State Commission on Radio Frequencies (GKRCh) to use the radio spectrum and specific equipment on a specific frequency band in a specific area of Russia prior to the certification process. • The Federal Service for Control over Healthcare and Social Development (Roszdravnadzor) is the main government agency responsible for registration of medical equipment, including foreign-made equipment. Applications for registration can include certificates of compliance obtained from other jurisdictions, such 11
  • 13. Engineer’s Guide to Global EMC Requirements o ISO 9001, ISO 9002, ISO 13485, and ISO 13488 certificates which should be notarized in the country of origin. o Certificates of registration of medical equipment issued by a respective government agency in the country of origin, such as FDA certificates, EC Certificates (CE Mark) and Declaration of Conformity. All such certificates should be notarized in the country of origin. o Electrical safety and EMC (electromagnetic compatibility) certificates, The Russian EMC standard corresponding to IEC 60601-1-2 is GOST R 50267.0.2.Jurisdiction Russia - EMCProduct type ITE Radio Appliance MedicalAuthority GOST Glavgossvyaznadzor GOST RoszdravnadzorApproval Certification, Certification Verification RegistrationProcedures licensingIn-countrytesting No Yes No Yesrequired?MRA with No No No NoUS?Marks GOST-R No GOST-R NoFAR EASTJapan • The Ministry of Economy, Trade and Industry (METI) is responsible for appliance safety, including RF emissions (EMI). Immunity is not required. In 1999, the Electrical Appliance and Material Control Law was revised to become the Electrical Appliance and Material Safety Law (current law), which was implemented on April 1, 2001. Products subject to regulation are mandated to be labeled with the PSE mark. A wide range of products can be self-verified to the requirements and carry no regulatory marking. The RF emissions limits established for appliances are similar to corresponding CISPR standards, although deviations exist. • EMI from Information Technology and Telecom equipment has been handled by a private, non-governmental, membership-based Voluntary Control Council for Interference by Information Technology Equipment (VCCI). The VCCI labeling has become so well accepted in some domestic markets that it has become a de facto regulatory gateway. With the new US/Japan Telecom MRA signed in February 2007, access to VCCI labeling will be available through either the membership route or by local accreditation to the VCCI standards based largely on CISPR 12
  • 14. Engineer’s Guide to Global EMC Requirements • The authority for radio regulation in Japan is the Ministry of Internal Affairs and Communications (MIC). The technical requirements are contained in Radio Equipment Regulations dating from 1950 and have been updated numerous times since. Radio rules published by private certification bodies such as TELEC, or by industry associations such as ARIB (Association of Radio Industries and Businesses), are not to be confused with the official MIC technical requirements, although they may all seem very similar. The MIC radio rules are similar to corresponding FCC rules but there are many differences, especially with regard to frequency allocations. • Medical products in Japan are regulated under the authority of the Ministry of Health, Labor and Welfare (MHLW). EMC requirements have been phased in over several years, with the last transition period for existing products just ended in March 2007 for Class I devices. The applicable EMC standard JIS T 0601-1-2:2002 corresponds to IEC 60601-1-2 first edition. This is soon being superseded by IEC 60601-1-2 2nd edition; the 2nd edition may be used currently with justification.Jurisdiction Japan - EMCProduct type ITE Radio Appliance MedicalAuthority MIC METI MHLWApproval Certification, Certification, Registration LicensingProcedures SDoC verificationIn-countrytesting No No No Norequired?MRA with Yes, 2007 Yes, 2007 No NoUS? Class B: VCCI mark TechnicalMarks Conformity PSE or none None Class A: Kanjii Mark textChina (PRC) • The People’s Republic of China (PRC) has enforced EMC regulations since 1999, largely emissions only. Under the Compulsory Product Certification System (CPCS) implemented in 2002 and under the authority of the Certification and Accreditation Administration of the PRC (CNCA), a number of listed product categories must carry the CCC certification mark. The CCC mark includes provisions for indicating safety (“S”) or EMC (“EMC”) or both (“S&E”). The implementation rules for compulsory product certification specify the applicable procedures and standards by 13
  • 15. Engineer’s Guide to Global EMC Requirements type, in a numbering format: CNCA-nnC-mmm:year. Examples are given in the table below. • Radio approvals are under the overall authority of the Ministry of Information Industry (MII). The State Radio Regulation Committee (SRRC) Certification Center, under the MII, is directly involved in the approvals. Mobile terminals, including cellular base stations and handsets, are classified as terminal equipment and are so regulated. Quality assurance is also part of the certification process. PRC radio standards are drawn from FCC, TIA and ETSI, including EMC requirements. • Many PRC standards are identical to international, FCC or ETSI standards. For example, the PRC standard GB4343 is equivalent to CISPR 14, and GB9254 mirrors CISPR 22. The IEC standards IEC 61000-3-2, -3-3 and 61000-4-x are references. Unfortunately, only in-country testing is permitted at this time. • Medical devices fall under the authority of the State Food and Drug Administration (SFDA) and optionally the Ministry of Health (MOH). Medical devices are classified according to risk (I = lowest, III = highest) as with many other medical regulatory regimes. Implementation rules for medical products reference many IEC-particular medical electrical standards (IEC 60601-2-x). The SFDA requires type testing and factory audits.Jurisdiction People’s Republic of China - EMCProduct type ITE Radio Appliance MedicalAuthority CNCA CNCA CNCA SFDA, MOH Certification; see Certification; Certification; Certification;Approval see: CNCA-08C-032 see: see: to 043 forProcedures CNCA-07C-031 CNCA-01C-020 CNCA-01C-016 examples; also for examples RegistrationIn-countrytesting Yes Yes Yes Yesrequired?MRA with No No No NoUS?Marks CCC CCC CCC CCCChinese Taipei (Taiwan) • The authority for safety and EMC for a wide variety of appliances and equipment in Taiwan is the Bureau of Standards, Metrology and Inspection (BSMI). RF 14
  • 16. Engineer’s Guide to Global EMC Requirements (EMI) are regulated. Safety and EMC standards are derived from the IEC. For example, the limits in CNS 13438 are equivalent to CISPR 22. • The National Communications Commission (NCC, formerly DGT) has authority over radio equipment. Many technical standards, especially for short range devices, are identical to FCC rules. • Taiwan’s Department of Health (DOH) regulates the importation of medical equipment. To market a medical device in Taiwan, the DOH pre-marketing registration approval must be obtained before the Board of Foreign Trade (BOFT) of the Ministry ofEconomic Affairs (MOEA) will issue an import license. The DOH, following many other economies, has grouped medical devices into three classes: I, II, III. EMC is required according to IEC 60601-1-2:2001, corresponding to the standard DOH-00003.Jurisdiction Chinese Taipei - EMCProduct type ITE Radio Appliance MedicalAuthority BSMI NCC BSMI DOHApproval DoC and Certification, Certification LicensingProcedures certification registrationIn-countrytesting No No No Norequired?MRA with Yes, Phase I Yes, Phase I No NoUS? Commodity CommodityMarks NCC No inspection mark inspection markConclusionThis paper has provided a quick overview of what is required to ensure that EMCrequirements are legally met for the countries in which you want to market your products.Although it is necessarily brief, it serves as a guide with which you can develop your ownlist of country requirements.As you expand your list, you will be able to weigh the challenge of meeting compliancecriteria and procedures for several nations simultaneously. Compliance has to be taken veryseriously; the penalties for not complying vary from simple quarantine of your products atcustoms to severe measures such as monetary fines and even 15
  • 17. Engineer’s Guide to Global EMC RequirementsIf global EMC compliance issues are a recent challenge for your company, or if your currentcompliance staff are stretched thin, it may be beneficial to partner with Intertek-ETL Semko,a proven leader in EMC test and certification worldwide. We have more than 322laboratories in 110 countries around the world, 20 of them in the US alone, In addition toMRA arrangements, we have special agreements with agencies and labs in many othercountries including Israel, Brazil, Russia, and Belarus.By working with a partner lab, it is easier to assemble a product- or technology-specific testand certification plan that maximizes your testing dollar and gives you the additionalresources needed to seek global compliance. You have the security of knowing that theplan is defensible in the face of management scrutiny and traceable in case of an audit.And it can be modified easily as technology and business structures change.For more information, go to Call 1-800-967-5352 or email gets you the answers you need—within 24 hours. We look forward to helping 16
  • 18. Insider’s Guide to Faster Safety & EMC Testing Intertek Testing Services 70 Codman Hill Road, Boxborough, MA
  • 19. IntroductionBringing a new product to market is a complex and involved process thatrequires the talent and expertise of a wide range of personnel within anorganization; business strategists, product designers and engineers, productionteams and line staff to name a few. Amidst the flurry of development activitywithin these teams, Safety and EMC product compliance issues may seem to bea low priority – at very least until a prototype is built. Indeed how can you testsomething for compliance when it doesn’t actually exist? By postponing compliance considerations until later inthe development cycle, it can cause delays in launchinga product to market. Testing can reveal non-conformities that require a product redesign ormodification then retest – lengthening the complianceprocess significantly. Indeed it is common thatmodifications made to a product for EMC compliancecan effect safety compliance. For example, having toadd extra insulation into a product can reduce thecurrent creepage and clearance distances required forsafety purposes, potentially making it unsafe. Similarly,changing bypass capacitors to comply with safetyleakage current requirements can throw off EMCcompliance. The product then has to be modified to fixthis problem and then retested for safety.With such a potentially complex situation, it seems obvious that product safetyand EMC compliance should be considered from the earliest concept stages ofdevelopment (and in an integrated way) to keep launch disruption to a minimum.Product modification and retest delays can have a critical impact on yourbusiness, potentially costing you thousands in lost revenue (missing out onHoliday sales for example) as well as damage to your brand. Your competitorscould get their rival products to market first, making them - in a consumers mindat least - a “leader” and everyone else that comes after a “follower”.In this document, we will explore some simple, practical strategies that ensurethese compliance considerations can be addressed early, and enable thecompliance process itself to be optimized to help reduce time to market, costs,chances of delay and the likelihood of having to make frustrating modificationsand retests to your product.
  • 20. Knowledge is PowerIt is a cliché to say knowledge is power, yet despite that, it is true.When a company decides to expand its portfolio of products, the first thing doneis market research. Is the product needed/wanted in the marketplace? What arethe competitive products, and what are their weaknesses? What features wouldmake the new product better than anything else available? What would its lifebe? Would it need to be repairable/upgradeable? Does it have to be functional oraesthetic or both? How much should it cost? And most importantly, to whom isthis product targeted and in which countries can it be sold? These last two items of information are essential knowledge for the development team, so try and get a copy of the market research for the proposed product. Depending on the depth of the research, this will give some indication as to any special Safety or EMC conditions that may have to be considered during the design (e.g. Is this product for home or commercial use; is it aimed at able-bodied users? Or children or the elderly?) and it will also show which regional regulations will have to be met.This knowledge is key to organizing the compliance schedule and budget itselfas you can use the existing knowledge of your engineers to identify the probableSafety and EMC test plan and likely costs – based on previous projects. Forexample, in the US, domestic products must be tested for EMC emissions, notimmunity. In Europe, domestic products must be tested for both. If your productis going to Europe, your test plan for compliance in this region is therefore likelyto take a little longer, cost a little more and will probably require more samplesand spares to be provided to the test house. These factors can then be built intoyour compliance plans, helping you to anticipate the requests of the test house,saving you time when you actually come to the testing stage.
  • 21. Standards & Local DeviationsKnowing the safety and EMC regulations for a newproduct in the target market is essential for theproduct development team. This enables them toobtain appropriate Standards for those markets(indeed they can select Standards that give themmaximum geographical coverage) and design theproduct with the safety and EMC requirements ofthese Standards in mind.Standards & JurisdictionUS - FCC/ FDAUS/EU - FCC, IEC, CENELECAsia Pacific - FCC or IEC with deviationsProduct Jurisdiction StandardITE USA FCC Part 15, 60950-1ITE EU, Asia CISPR 22/EN 55022, CISPR 24/EN55024Medical USA, International IEC 60601-1-2Test/Measurement 61010-1Audio/Visual 60065Household Appliances 60335-1Electrical Tools 60745-1ISM USA FCC Part 18ISM EU, Asia EN 55011 +…Lab USA ExemptLab EU EN61326-xRadio USA FCC Part 15, 22, 24, 25, 27, 74, 90, 95Radio EU ETSI EN, EN 301 489 -x
  • 22. Insider’s Guide to Faster Safety & EMC TestingPurposefully designing a product for safety and EMC conformity seems acautious and conservative approach to product design that restricts creativity andinnovation, but it is likely to reduce your chances of product failure at the testingstage.A Note on Standards Use Many companies maintain an in-house library of Standards that relate to their product ranges with a view to ongoing safety and EMC compliance within their target markets. These libraries can be extremely effective in aiding designers, but two issues need to be highlighted. The first is the matter of interpretation. Some of the language used in Standards – particularly inthose sections relating to specific tests to be conducted, can be interpreted in anumber of ways. Calling upon the expertise of a testing and certification partnerto interpret the fine detail of a Standard can help designers and engineersovercome the hazards of ambiguity and potential product non-conformity. If theissue has particular subtleties, your test partner can even approach theStandards Developing Organisation (SDO) directly for a definitive explanation.The second issue with in-house Standards libraries, is the need to maintain thelatest version of the Standard. When potentially dozens of Standards need to bemaintained, it is possible that an expiring document may be overlooked. Hereauditors and quality managers play their part in keeping the available documentsup to date – but again your testing and certification body can provide you with thelatest (and upcoming) Standards updates and information on local safety and orEMC deviations that might apply to a sub-section of your target market.Standards are expensive! But on the other hand, how expensive is it to re-work anon-compliant product design, or, how expensive is it to miss a product launchdate in the market place? Purchase of the standard is a good investment and isquite inexpensive when compared to the cost of re-submittal to the test lab.
  • 23. Insider’s Guide to Faster Safety & EMC TestingUnderstanding Dates of Withdrawal (DOW) and Standard VersionterminologyEnsuring that you’re using the appropriate standard is an obvious thing, butunderstanding the validity of dates within those standards is critical to using theright one! It would be incredibly frustrating to commission product tests against aStandard in your library and then find that it is soon to expire and that any testingand certification will need to be revisited.The new version of the Standard my not require any additional tests to becompleted – it could be a something as simple as a new labelling requirement,but it could require product modifications and a re-test. Understanding how thedating information in Standards works could save you time and expense inhaving to revisit your test program soon after completion because the Standardthat was tested against is no longer the newest version.Outlined below are some brief explanations of critical Standard dates andterminology for standards in the EU:Approved DraftThe Approved Draft Date is usually found in the Foreword atthe front of the Standard. This date is essentially when theStandard text was “Approved” by CENELEC, prior topublication by the National Standards Bodies.DOP - Date of PublicationThe DOP or Date of Publication is the date by which the Standard must bepublished by all countries’ National Standards Bodies. The DOP is usually 6-12months after the document has been “Approved” by (for example) CENELEC andonce the document is published, it becomes the current version of the Standard.Amendment DatesAs you would expect, Amendments to Standards (also found in the foreword anddesignated with the letter A and numbered in sequence e.g. A1, A2 etc) alsohave an Approved Draft Date and a DOP, but in European Standards, you willalso find a Date of Withdrawal (DOW). This DOW indicates the date when theStandard it is associated with can no longer be used on its own - i.e. without thenew Amendment. DOWs are also found on fully re-issued Standards. It doesn’tindicate that the Standard as a whole will cease to be current on that date.
  • 24. Insider’s Guide to Faster Safety & EMC TestingAmendment Numbers An interesting point to note is that Amendments are numbered in a specific way. Generally speaking a single number after an A, e.g. A1, A2, A3 etc indicates that an amendment applies to both IEC and EN versions of the Standards. However, if an amendment only applies to the European Standards - say in order to comply with a piece of European legislation then a two digit number will be used, e.g. A11, A12, A13 etc. Essentially ifyou have an A1 amendment and an A11 amendment in the same document -you haven’t missed amendments 2,3,4,5,6,7,8,9 & 10! - It’s just that there are twodifferent amendments to that Standard; one for International use, one forEuropean.BS, EN & IECThe name of a Standard will be designated with a BS, EN or an IEC. A BSdesignation indicates a British Standard, an EN designation indicates that it is aEuropean Standard and an “IEC” designation indicates a worldwide Standard.Part 1s and Part 2sMany Standards will be divided into part 1s and part 2s. Part one usually refers toa generic category of products - for example “Household and similar electricalAppliances” and gives details of general requirements for them and part tworefers to specific items in that category, say for example room heaters.REMEMBER!For certification purposes, a product can only be said to conform to a Standardthat is still current. For example if I test a product to a particular Standard andthen an amendment is published for it, my product will not comply with the mostcurrent (now amended) version of the Standard once the Date of Withdrawal onthat Amendment is passed.Similarly, if you have a Certification for a product that doesn’t expire for severalyears - but the Standard that was used to get that Certification gets Amendedbefore your certification runs out, you must contact your Certification Body toenable them to determine what you need to do to comply with the latest version
  • 25. Insider’s Guide to Faster Safety & EMC Testingof the Standard. Sometimes you may need to do additional testing - sometimesthe conformity is purely a documentary exercise but you must ensure that yourproduct meets the most current version of the Standard.The Devil is in the Details: Designing for ComplianceContinue to use the knowledge and expertise of your product designers andengineers to “design for compliance”, but also use the available productStandards as design reference tools and even look at existing best of breedproducts to see how they have overcome certain design challenges.By establishing safety and EMC compliance as afundamental design goal, along with functionality,ease of use, aesthetics etc at the start of the designprocess, compliance issues can be tackled earlier inthe design cycle. Compliance will be seen as aproduction imperative not a last minute addition tothe project. This will reduce chances of productfailure at the test phase as the product itself will be“designed for compliance”.Issues to consider during the design phase: • Materials – knowing the characteristics of the materials that could be used in the product and how they behave in certain environments can help you choose materials that make optimum contribution to safety and EMC compliance • Printed Circuit Boards (PCBs) – Consider the architecture and positioning of PCBs for optimum protection • Ventilation – Keeping a product cool is important but will the venting enable EM radiation to seep out at unacceptable levels? Or bring instability to the system? • Shielding – by adding shielding to prevent EMC emissions, are you reducing the clearance of electrical components within the system? Will the extra material enable the system to overheat? • Family resemblance – Perhaps minimize the differences within suites of products if you want to minimize the testing they have to undergo. The
  • 26. Insider’s Guide to Faster Safety & EMC Testing fewer the differences between them the less complicated (and costly) the testing will be. • Cabling – does the cabling have optimum shielding and protection? • Software and virtual testing – some immunity upsets can be corrected or mitigated by suitable operating software/firmware design. Also, consider the use of virtual testing software. A number of IT packages are available that can model and analyse a product design that can help designers design for compliance.Choosing ComponentsWhere possible use listed or certified components in critical systems in theproduct. e.g., controls, transformers, components in the 120 or 240 primarycircuit, etc (and know their ratings and conditions of use) as these will contributeto the overall compliance of your product.Also with some specific products – like UK plugs for example, having certifiedsub-systems like pre-approved moulded pin inserts means that some of yourtesting has already been done and you could save money on your overall testprogram. The temptation to use non-listed components because they are cheaper can be a false economy – they are likely to be unproven, and unless the manufacturer is reputable or at least already trusted by you, they could be of questionable quality. In addition, such non-listed components may require extensive additional evaluation and testing, including annual re-testing. Just remember if a batch ofcomponents (and even materials) seems a bargain that is too good to be true, itprobably is.A Note on Modifying Established ProductsIf you are redesigning or modifying an existing product, even if you are simplyswapping one component for another from a different supplier, don’t forget to tellyour testing and Certification/Approval partner, so they can determine if anyadditional testing is required. Swapping one component for another may haveimplications that weren’t anticipated when the substitution was made and if youdon’t notify your partner; it may invalidate your certification. Very often
  • 27. Insider’s Guide to Faster Safety & EMC Testingsubstitutions have no impact on a product at all, and no further testing is needed,but it is important that documentation is updated with the change for auditingpurposes.Putting Pen to PaperDocumenting the design and production process is invaluable for the complianceprocess. Quality Management tools and Project Management systems provide auseful structure for capturing information that not only can it help an engineer re-trace their steps and identify a problem if a product shows a non-conformityduring the testing process, but it will also help them to keep track of componentsand schematics for easy reference – particularly if they are creating a suite ofproducts.The testing and certification team at yourpartner laboratory will require access tothe component and materials lists as wellas circuit diagrams and drawings in orderto be able to test and assess the product.Surprisingly, a great many testing andapproval projects get delayed, not becauseof the modification of product or because afailure of tests, but because the test labhasn’t had all of the paperwork they needto move a project forward. It seemsbureaucratic, but as test houses andcertifying bodies are regularly audited toensure the work they do is to a consistentand of high standard, they need to have allof the relevant documentation necessaryto conduct the work. Sometimes the mostsimple of required “paperwork” (usermanual, installation instructions, productmarkings, etc.) is not provided. If amanufacturer can have all of the relevantdocumentation ready for the test house,frustrating delays can be avoided.In your records, it is also beneficial to keep a list of contact names and numbersand email addresses for the team at the test lab, and some calendar notes tocheck in regularly with them to check on the project progress. Some
  • 28. Insider’s Guide to Faster Safety & EMC Testingmanufacturers don’t do this as they want no part of the compliance process, butmany others have found an active dialogue with the test house and anunderstanding of and proactive involvement in the process can help reduce thetime it takes and reduces the number of potential issues that could arise.Design ReviewMany manufacturers have found it beneficial to have a design review conductedby their test or certification partner. This highlights any design issues early andcan be conducted using the circuit diagrams, component lists, design drawings –and if it is available, a prototype. Initial discussions with the certification partnercan even begin with an artists rendering or cardboard mock-up. If necessary theproduct can then be modified or re-worked before ever reaches the laboratory.Your partner will not only review the product but they can also be used as asource of reference for interpreting Standards.The Compliance Process Understanding the Safety and EMC and compliance process and actively preparing for and participating in it can help reduce the time it takes to complete it successfully. It is tempting to hand a product over to a test house, and take a “hands off approach” to compliance. Obviously your laboratory partner has both the expertise and the facilities to test a product to Standard and is fully capable of managing the process. However knowing the type of tests your product will undergo and where possible conductingsome preliminary testing yourself, can help give you some initial feedback onwhere your product might fail, enabling you to make appropriate modificationsbefore a product reaches the formal testing stage.
  • 29. Insider’s Guide to Faster Safety & EMC TestingWhat can a man with a radio do?The most basic of all EMC tests – that you can conduct yourself withoutspecialist equipment or test chambers - is the radio test. Switch on your radioand hold it near your live appliance and see if the reception becomes distorted. Ifit does, it’s likely that your product needs better emissions mitigation.Other basic bench tests can usually be conducted at site with some help fromyour test laboratory team. They can give you direction on equipment you willneed, guidance on specific tests and even observe some testing so it can beincluded in the formal compliance assessment.Keep it in the FamilyWhen you are submitting products to the laboratory for testing, group them into afamily of products, and submit as many similar items as is feasible at the sametime. This will help to reduce the cost and time required for the complianceprocess for multiple items. If that isn’t possible then try and arrange a worst case(fully loaded) configuration that can represent the other units in the family.Partners Choosing to work collaboratively with a compliance partner like a test house or a certification body from the beginning of the design process can also bring clarity and speed. Particularly if a manufacturer’s design team has a thorough understanding of the compliance process and can prepare in advance for the requests of test house. As well a providing advice on what Standards should be referenced during the design phase and how to interpret them; they can also conduct design review and give general guidance throughout thedevelopment of where issues typically lay. This will help manufacturers toprepare their product for test and reduce the likelihood of failure.
  • 30. Insider’s Guide to Faster Safety & EMC TestingConclusionIn a global market where the ability to innovate and respond to market needs withnew and vibrant products is the mark of world leading brands, time to market is akey factor in determining both the success of a particular product and ultimatelythe ongoing commercial success of a company. As each trading area in the worldhas its own set of specific regulations and requirements for these products,minimizing the time to meet these is critical to reducing time to market.To reduce the time it takes to complete the compliance process the manufacturercan: • Consider compliance issues from the beginning of the design process. These need to be an integral part of the creation of a new product, not an afterthought. • Use the knowledge and expertise available to them to ensure they are designing product to the latest versions of the Standard, and that they have taken into consideration the local deviations that may apply to their product. A test partner will be able to advise on what Standards to use, and if required, how to interpret them. • Improve their understanding of, and increase their involvement in the compliance process. By anticipating the needs of the test house, response and delivery times can be improved. • Design for compliance. Deliberately use appropriate materials, proven designs and approved components that provide adequate EMC shielding and reduce hazards from electrical shock. • Maintain a detailed technical file on the project – so when the test house makes a documentation request, everything required is quickly available. • Utilize a design review from their partner test house to ensure that they are on the right track and that any issues can be spotted and rectified early in the product development process.There is no magic solution to prevent all of delays with EMC and Safety testing.Sometimes products fail and sometimes delays occur for other reasons, but withthese simple, common sense efforts, they can at least be reduced. Designing forcompliance is an unromantic notion, but a common sense one. You can optimizethe testing process with proactive involvement, but a well designed product thatmeets all of the criteria required of it, will be the most influential factor in gettingthrough the compliance process, fast.
  • 31. Insider’s Guide to Faster Safety & EMC TestingAbout the AuthorsRoland Gubisch is the Chief Engineer, EMC and Telecom, Intertek Testing Services. Inthis capacity he is responsible for the technical activities in EMC andtelecommunications testing of Intertek laboratories in the US and Canada. He has beenwith Intertek for 17 years. He is also the Certification Body Manager at Intertek for FCCand Industry Canada radio certification activities.His industry activities include the IEEE Working Group for Power Line CommunicationsEMC standards, membership in the Administrative Council for Terminal Attachments(ACTA), and TIA liaison groups with the FCC for wireless communications. He holdsdomestic and international patents in the fields of optical and chemical instrumentation,and network test apparatus. He is a member of the IEEE, and IEEE Communicationsand EMC Societies.Jim Pierce is the Chief Electrical Engineer for Intertek Testing Services. He began hiscareer with UL over 30 years ago as an Engineering Technician and moved up in theorganization to managing 40 engineering staff. He joined Intertek in 1990 and heldvarious engineering management positions over the years.His responsibilities include: preparing and conducting training programs for Intertek’stechnical staff and monthly worldwide training webinars and annual requalification ofReviewers Webinar sessions.Mr. Pierce is a member of the National Fire Protection Association (NFPA) and iscurrently serving on National Electrical Code (NFPA 70) Panel #18 and is also amember of the NFPA 79 Technical Committee (Industrial Machines). He also serves onmany ANSI, NEMA, NFPA and UL Standards Maintenance Review Boards. In addition,he has been an Inspector member of the International Association of ElectricalInspectors (IAEI) and has served on their monthly Code Panel Forums, for over 17 years.Natasha Moore is a technical author and editor specializing in electrical safety andcertification information. Based at Intertek UK, she was the contributing editor of ASTABEAB’s Update magazine and recently wrote the Intertek whitepaper “The EngineersGuide to Solving World Problems: 5 Strategies for Efficient Global Market Access.” For more information on specific testing and certification information, please contact Intertek at 1-800-WORLDLAB, email, or visit our website at publication is copyright © Intertek and may not be reproduced or transmitted in any form in whole or in part without the priorwritten permission of Intertek. While due care has been taken during the preparation of this document, Intertek cannot be heldresponsible for the accuracy of the information herein or for any consequence arising from it. Clients are encouraged to seekIntertek’s current advice on their specific needs before acting upon any of the content.
  • 32. Why 50% of ProductsFail EMC Testing the First Time Intertek Testing Services NA, Inc. 70 Codman Hill Road, Boxborough, MA 01719 Phone: 800-967-5352 Fax: 978-264-9403 Email: Web:
  • 33. SummaryA large percentage of electronic products fail to meet their target EMC requirements the first time they aretested. In this article we look at some of the possible reasons for that failure rate, and what designers andmanufacturers can do to improve the success rate and therefore time to market.Why do 50% fail?During the last several years, we have observed that initial EMC test failure rates for electronic productshave decreased gradually. Improved success may be the result of growing awareness of EMC designconsiderations, use of EMC software, reduced circuit dimensions or all of these factors. Nevertheless, wecontinue to see EMC test failure rates around 50%.Looking more deeply into the numbers, we note that, for example, medical products are slightly moresuccessful (~40% initial failure) at meeting their EMC objectives than information technology equipment(ITE). One might expect otherwise from the added performance constraints of the medical EMC standardIEC 60601-1-2 over the ITE standards CISPR 22 and 24, but two factors may work in favor of medicalproducts. They are often designed more conservatively and with more review than ITE, and the IEC 60601-1-2 standard it self allows justified derogations from the limits. But overall, the same basic EMCconsiderations apply to both medical and ITE. 60 Fortunately, the EMC learning curve for products that fail 50 ITE initially is quite steep. Presumably taking advantage of both the EMC education provided by the first go-around, as well 40 Medical as the pinpointing of EMC problems, manufacturers reduce 30 the failure rate on the EMC re-testing to the level of 5% - Learning curve – 7%. Very challenging products may require a third round of Failure 20 plus knowing exactly what EMC testing, for which we observe a failure rate reduced to 10 1% - 2%. 1st 2nd 3rd trialBased on our experiences with a wide variety of equipment suppliers, we can summarize the leadingobserved causes of initial EMC failure as: • Lack of knowledge of EMC principles • Failure to apply EMC principles • Application of incorrect EMC regulations • Unpredicted interactions among circuit elements • Incorporation of non-compliant modules or subassemblies into the final productThese topics are discussed briefly in the context of a product design and development program intended tomaximize the likelihood of success in the initial EMC 1
  • 34. EMC regulationsAlthough RF interference considerations have existed since the advent of radio, commercial EMCregulations (both emissions and immunity) are relatively recent – and continuously changing. Equipmentdesigners and regulatory compliance engineers have to work hard to identify and keep abreast of the EMCregulations that impact their products. Of course, regulations should not be the only design driver.In the USA, the Communications Act of 1934 established the framework for resolving radio interferenceissues. Parallel laws were enacted around the world, with Germany providing early leadership in laws andstandards that provided a model for the European Union.After the Second World War and the growth of electronics, specialized EMC standards were created toassure reliable equipment operation in such critical applications as aircraft, military, medical andautomotive. The regulation of RF emissions from consumer products was given a boost from the advent ofthe personal computer. Numerous complaints of interference to radio and TV reception from personalcomputers led in the United States to the adoption of Subpart J to the FCC’s Part 15 rules in 1979. Theregulation of RF emissions from personal computers has spread throughout the world, with a fewexamples shown below: • FCC Part 15, subpart J 1979 • IEC CISPR 22 1985 • VCCI in Japan 1985 • Canada Radio Act 1988 • Australian EMC Framework 1996 • Taiwan ITE EMI 1997 • Korea ITE EMC 1998 • Singapore EMI for telecom 2000 In 1989 the FCC consolidated its Part 15 rules into Subparts A, B and C. But thanks to the unstoppableflow of new communication technologies, the Part 15 rules have grown back to include Subpart G, with anew Subpart H already proposed. Today, RF emissions are regulated in most developed countries to protectbroadcast services (radio, TV) and sensitive services (radio-navigation, satellite communications, radio-astronomy).The first widespread application of RF immunity requirements was introduced with the European Union’sEMC Directive published in 1989 and originally to take effect in 1992. However, the lack of suitable EMCstandards – and the lagging preparedness of manufacturers – led to a delay until 1996. The original EMCDirective 89/336/EEC is replaced by a new Directive 2004/108/EC, with a transition period 20 July 2007 –20 July 2009. EMC for radio equipment in the EU is mandated by the R&TTE (Radio andTelecommunications Terminal Equipment) Directive 1999/5/EC.Worldwide EMC regulations, including limits and measurement procedures, are changing constantly andrepresent a moving target for product 2
  • 35. RF emissions limits have been established for the threshold sensitivities of typical “victim” receivers such asradio and TV, and on the “protection distances” that may be available to increase the spacing between RFemitter and victim. The common protection distances are 10 meters for residential environments and 30meters for non-residential. Most emissions standards allow scaling to other measurement distances such as3 meters.The equipment designer needs to know that the EMC environmentinterpretation of EMC environments can differ USA EU+between jurisdictions. In the USA, the FCC hasdefined the Part 15 Class A environment asanything except residential or consumer. EU non-residential industrial Class Ageneric EMC regulations define Class B morebroadly. It may include commercial and light residential,industrial environments. For ITE, however, it is Class B residential commercial,acceptable to allow Class A emissions in light industrialcommercial and light industrial locations. Emissions increase Immunity disturbancesImmunity environments are generally defined by the electromagnetic “threats” or disturbances that mayexist there. For example, the generic industrial immunity standard IEC 61000-6-2 defines an industrialenvironment both from the nature of the AC connection: - to a power network supplied from a high or medium voltage transformer dedicated to the supply of an installation feeding manufacturing or similar plantwhich could conduct disturbances from the equipment to other “victims,” and to the surrounding“threats” as: - industrial, scientific and medical (ISM) apparatus - heavy inductive or capacitive loads are frequently switched - currents and associated magnetic fields are highThe equipment designer or design team needs to assure that their EMC objectives take into account anyregulatory differences among jurisdictions regarding the definitions of the EMC environment.Consider EMC early in the design processThere are many opportunities during the productdevelopment process between concept and marketentry where EMC criteria should be established, The design processvalidated, tested and perhaps modified. The Design concept Target Systemfeedback implied in Figure 3 does not necessarily rulesmean a mid-course correction (although one mightbe justified), but rather an opportunity to captureEMC information for use in future projects as ameans of process improvement. ISO 9000-registered manufacturers should consider including Regulatory Functional Initial release evaluation 3
  • 36. these review steps in their equipment development program.Some specific EMC considerations are suggested below for each of the design steps shown in Figure 3:Target Specifications The details (include functional and regulatory— EMC) Are all the jurisdications specified? Have the requirements changed? Is the environment correct?System Architecture The structure and details—EMC How many layers in PCBs? Are reactive circuits located away from I/O ports? Are I/O ports isolated/shielded? Are IC families appropriate for speeds needed? Will housing provide shielding?Design Rules The circuit and layout constraints—EMC Are RF signal traces short and/or embedded? Are bypass caps located and sized optimally? Are ground planes low-impedance, and earth bypass provided? Have sensitive designs been modeled?Regulatory Evaluation Is it legal? If not modify—EMC Were places provided for optional filtering/bypassing? Are ferrites cost-effective? Can spring fingers be added to the enclosure? Will a shielded cable help? Board re-spin? Design for complianceNumerous books provide a thorough treatment of EMC design. In a limited space we can only mention afew key considerations for each of the major categories of: - Components - Logic families - PCB layout and I/O - Cables - Enclosure and shielding - Software and firmware 4
  • 37. Smaller, leadless components are contributing to the increased EMC testing success rate in two ways: (1)the absence of leads reduces the connection inductances, allowing more effective bypassing and lowerground bounce, and (2) the smaller components permit smaller PC boards, reducing trace lengths that canradiate or absorb RF energy. The effect of lead inductance is illustrated in bypass impedance Figure 4 for a leaded bypass capacitor. At low frequencies the capacitive impedance decreases as frequency increases, allowing for 10 good bypass characteristics. Above a resonant point determined by the capacitor’s nominal value and its internal and external lead impedance, ohms inductances, impedance increases with 1 frequency – reducing the capacitor’s effectiveness at the higher frequencies. Leadless bypass capacitors are more effective at high frequencies owing to their lower connection inductances. 0.1 0.01 0.1 1 10 The same argument can be applied to the frequency, GHz parallel power and ground planes in a PC board. These constitute effective bypass capacitors with low 5
  • 38. Logic familiesSelection of logic families for a particular design should use the slowest speed consistent with targetfunctionality. Excessive speed and/or high loads can cause EMC problems, because: • Emissions increase with power consumption • Emissions increase with slew rate/clock speed • Emissions increase with ground bounce • Emissions increase with output loadingDesigners confronted with the need to pass high-speed signals over long distances might wish to considerusing LVDS (Low-voltage differential signaling) logic. LVDS is often used to communicate video data fromthe base of a laptop computer to its flat-screen display. The key benefits of LVDS include a low voltageexcursion and differential drive. PCB layout and I/OKey decisions faced by the designer include number of planes and locations of components. Planes can beused to good advantage for shielding (of internal traces) or bypassing (using the capacitance describedabove). There are tradeoffs because effective bypassing requires the planes to be as close together aspossible, but for shielding they have traces between them. Where unshielded cables exit the PCB, anydigital logic planes should be kept away because the planes carry noise.Traces should be kept as short as possible, and their high frequency impedance is minimized when theratio of length to width is no greater than 3:1. Short straight current elements radiate fields that are: - Proportional to the current they carry - Proportional to their (electrical) length - Increasing with frequencySimilarly, small current loops radiate fields that are: - Proportional to the current - Proportional to the square of the loop radius -- and the square of frequencyLocate I/O drivers as far as possible away from sources of high frequency (clocks) and near the ports theyserve. Otherwise, the high frequency energy will couple to the cables on the I/O ports and the cables willradiate above the applicable limits. CablesConductors exiting the enclosure can perform as effective antennas, radiating at frequencies that aresourced within the enclosure. If the conductors are a pair of wires driven differentially, the opposite andequal signal components on each will tend to cancel one another and any radiated emissions will beminimized. If the signals on each connector are not equal in amplitude and opposite in phase – as with asingle-ended drive – some energy will be radiated and may cause regulatory limit failure.Robust cable shielding can be an effective method of suppressing the emissions from a conductor carryinga single-ended signa. However, the outer shield onsuch shielded cables should be returned via theconnector to an enclosure ground and not a signal ground. The signal ground is generally polluted by noisethat, if connected to the cable shield, could cause the cable shield to radiate above regulatory 6
  • 39. Enclosure and shielding The equipment enclosure can provide shielding aperture shielding effectiveness to reduce RF emissions or improve immunity, 70 only if the enclosure is conductive (metal or plastic) and preserves the continuity of a shielding effectiveness, dB 60 conductive path around the electronic circuitry 50 inside. Any seams or holes in the enclosure 40 10 cm must be sufficiently small to attenuate 30 1 cm electromagnetic disturbances that could enter or exit. Small openings (see Figure 5) can be 20 tolerated, depending on the frequencies of 10 concern. In this chart the dimensions of 1 cm 0 and 10 cm represent the diameter of a circular 0.01 0.1 1 10 opening, the diagonal of a rectangular opening, frequency, GHz or the length of a thin slit or seam. Non- conductive enclosures provide good protectionfrom electrostatic discharge (ESD) but afford no shielding. Software and firmwareNot all of the “heavy lifting” for EMC compliance needs to be accomplished with hardware. Many of themost common immunity disturbances allow the equipment being tested to temporarily degradeperformance during the test, but recover automatically. This functionality can be provided by goodsoftware/firmware design at no hardware cost. These are prudent features in any case, not just for EMCcompliance: - checkpoint routines and watchdog timers. - checksums, error detection/correction codes. - ‘sanity checks” of measured values. - poll status of ports, sensors, actuators. - read/write to digital ports to validate. Pre-compliance testingIn cases where the product development uses modules or subassemblies that have not been previouslyevaluated for EMC, or where marginal EMC performance of the product is suspected, it is prudent toperform some pre-compliance EMC testing. This can only provide approximate results but could revealproblems at an early stage when the corrections can be made quickly and cost-effectively.If the developed product has been tested on an accredited EMC site and failed (or even passed), theaccredited test results can be used to correlate with results on a pre-compliance site to decrease theuncertainty of the pre-compliance results. Pre-compliance RF emissions sitesIt is possible to set up a simple 1m emissions site in an office or factory. By bringing the measurementantenna (which can be rented for the purpose) closer than 3m to the equipment being tested, interferencefrom ambient emissions is minimized. At frequencies above about 100 MHz reflections from any 7
  • 40. plane are not relevant in this configuration, so the customary office or factory floor is acceptable. Theantenna is kept at a fixed height of 1m. This site is not well-suited to large equipment, with dimensionsnear or larger than 1m. See Figure 6. If ambient radiated emissions are very high, they can be Pre-compliance EMI site excluded from the 1m pre-compliance site by constructing a screened room around it using a wooden frame and metal 1m mesh. Radiated reflections will be introduced, so any measurements made in the screened room are subject to EUT analyzer additional uncertainties. The screened room can also be used for conducted emission measurements using a LISN (Line Impedance Stabilization Network) or AMN (Artificial Mains floor - not a ground plane Network). Pre-compliance tools – emissionsWith a suitable pre-compliance site available, you can perform simple diagnostic tasks to isolate, identifyand mitigate sources of RF emissions. Take a set of baseline measurements across the frequency range ofinterest, using a suitable EMI receiver or spectrum analyzer (which can be rented for the purpose). Then,perform a succession of operations in turn and observe the results on the screen of the measuringinstrument: - Wiggle I/O or AC cables to correlate with emissions. - Remove I/O cables one by one to determine effect on emissions. - Shield AC cable to chassis with tin foil. - Selectively add ferrites, line filters or bypassing to localize reactive cable. - Use EMI probes (below)If an emission of interest has been identified, its source on the equipment or circuit board can likely beidentified by using either a proximity probe or a contact probe; see Figures below.The proximity probe is moved around the enclosure or circuit board until an emission is located at the samefrequency as the one found using the antenna. By locating the highest emission with the proximity probe,you have likely – but not definitely – located the source of the emission. The contact probe allows you totouch individual PC traces or component leads in searching for the frequency of 8
  • 41. Pre-compliance tools – immunityImmunity pre-testing requires you to generate electromagnetic disturbances that simulate the requirementsin the applicable immunity or EMC standards. The simplest way to perform ESD pre-compliance testing isto rent an ESD “gun” for the purpose. Be sure to review the ESD standard such as IEC 61000-4-2 in orderto follow the test procedures and setup as closely as possible. Use a similar approach to surge testing for astandard such as IEC 61000-4-5, and be sure to comply with safety precautions as the surge voltages canbe hazardous.RF radiated immunity testing is normally performed in a shielded chamber to avoid radiating illegal RFsignals across the radio spectrum. Unless you have constructed a screened room and determined that itprovides sufficient shielding effectiveness to prevent unwanted emissions from inside to outside, youshould confine any RF radiated emissions pre-compliance testing to the use of certified and/or licensedradio transmitters approved for use in the USA or in the test location. Some convenient transmitter typesand their operating frequency bands (for US operation) are listed below: – CB radio 27 MHz – Portable phone handset 49 MHz (be sure to check; many now operate in the 900 MHz, 2.5 and 5 GHz bands) – Garage door opener 300 MHz – Walkie-talkie 460 MHz – Cell phone, analog/TDMA 800 MHz – Cell phone, PCS 1900 MHz – Wireless LAN, Wi-Fi 2450 MHzIf insufficient RF immunity is observed during pre-compliance testing, you can experiment with conductivespring fingers to bridge enclosure discontinuities, filters at low RF frequencies and ferrite beads typicallyabove 50 MHz.Modifications for compliancePrudence dictates that a product which has never before undergone EMC testing be designed with a fewextra EMC ”hooks” that can be used in the event of EMC problems during regulatory testing. Such“hooks” can be as simple as PCB locations for extra bypass capacitors and/or ferrite beads, or alternateconnections for a larger AC line filter. If the equipment passes the regulatory EMC testing with flying colors,the optional positions remain unpopulated. This precaution can avoid board re-spins and a subsequentdelay in time-to-market, or even slipping outside of the marketing “window.” 9
  • 42. ConclusionIn summary, to increase the EMC success rate the designer should: • Be sure the regulatory specifications are correct and current • Take into account the impact of equipment architecture on EMC, and ensure that purchased modules also comply. • Consider EMC design rules, manual and/or automatic • Include places for EMC compliance modifications • Perform pre-compliance testing where possibleETL SEMKO is a division of Intertek plc (LSE: ITRK), a global leader in testing, inspection and certificationservices, operating in 322 laboratories and 521 offices in 110 countries throughout the world. Intertekprovides access to global markets through its local services, which include product safety testing andcertification, EMC testing and performance testing for customers in such industries as wireless technology,security, appliances, HVAC, cables and wiring accessories, industrial machinery, medical devices,telecommunications, lighting, automotive, semiconductor, building products and electronics. For moreinformation, visit, or call 1-800-WORLDLAB For more information on EMC, and testing products covered under Intertek’s scope, or to contact Intertek to begin your review right away, call 1-800-967-5352, email, or visit
  • 43. Effects of EMC on Smart Appliance Designs Written by Roland Gubisch 1-800-WORLDLAB
  • 44. Effects of EMC on Smart Appliance DesignsContentsIntroduction ..............................................................................................................1EMC - Electromagnetic compatibility .........................................................................1 Background .......................................................................................................3 EMC ..................................................................................................................3 Emissions - USA .................................................................................................5 Emissions - Japan ...............................................................................................6 Emissions - Australia...........................................................................................7 Designs for emissions compliance.......................................................................8 Emissions and Susceptibility - EU ........................................................................8 Designs for disturbance power compliance.......................................................11 Harmonic and flicker emissions ........................................................................11 Designs for harmonic and flicker emissions compliance.....................................12 Appliance susceptibility and EN 55014-2 ..........................................................12 Designs for susceptibility/immunity compliance.................................................14 Communications..............................................................................................15 Powerline communications...............................................................................15 Radio ...............................................................................................................16 Designs for communications compliance ..........................................................18 Product safety ..................................................................................................18 Functional safety ..............................................................................................19 Electromagnetic exposure ................................................................................19 EU low-frequency EMF limits: EN 50366 ...........................................................20 Designs for EMF compliance.............................................................................21 RF exposure from radios...................................................................................21 Designs for RF exposure compliance 2
  • 45. Effects of EMC on Smart Appliance DesignsIntroductionWhen we hear the term “appliance” we think of common household devices such asair conditioners, blenders, coffee makers, dishwashers, electric knives, fans,microwave ovens, refrigerators and vacuum cleaners. These examples contain amongthem motors, switches, thermostats and electrically-actuated valves – all well-knownelectromechanical technologies, with perhaps some simple solid-state electronicsadded. Newer appliance designs are reducing cost, expanding functionality and increasing reliability by adopting programmable electronics such as application specific integrated circuits (ASICs), microprocessors, and intelligent sensors, transmitters and actuators. In addition, such “smart” appliances are adopting powerline and wireless communication techniques to enhance their utility even further – for remote control over a “smart grid,” or for remote recordkeeping, for example.The migration of appliance technology from electromechanical to programmableelectronic and wireless has significant consequences for EMC design and regulatorycompliance. Even for simple appliances, the designer may be faced with unfamiliarstandards governing user safety and radio interference. For more complex appliances,stringent “functional safety” requirements may affect EMC testing.This document is intended to help the reader become aware of global EMC issues anddesign considerations for “smart” appliances. It is not intended as a comprehensivecatalog or toolkit. EMC consultants and test laboratories can provide targetedassistance with up-to-date information on regulations and compliance procedures.EMC - Electromagnetic compatibilityElectromagnetic compatibility is defined as the condition which exists whenequipment is performing its designed functions without causing or sufferingunacceptable degradation due to electromagnetic interference to or from otherequipment. EMC refers to a kind of environmental equilibrium. In this case, theenvironment is an electromagnetic one - consisting of invisible disturbances whichtravel through the air or through metal cabinets or 1
  • 46. Effects of EMC on Smart Appliance DesignsEMC has two components, illustrated in the diagram below: 1) Electromagnetic emissions, from the appliance itself; emissions from the appliance can interfere with radio and TV broadcasting or sensitive services such as radio navigation or radio astronomy. The term EMI (Electromagnetic Interference) refers to electromagnetic energy which interrupts, obstructs, or otherwise degrades or limits the effective performance of equipment; and 2) Electromagnetic susceptibility of the appliance to disturbances in its environment, resulting in appliance malfunctions caused by static discharges, radio transmitters, cell phones or other nearby electrical or electronic devices. The term Immunity refers to the condition which exists when equipment operates within acceptable limits when exposed to electromagnetic environments imposed by an external source.When a particular appliance is not generating excessive disturbances, and when it isoperating correctly in the presence of such disturbances, the condition ofelectromagnetic compatibility is satisfied. Whether or not EMC is subject togovernment regulations in a particular market, EMC is an important design goal toassure reliable appliance operation and to avoid interference to nearby devices andradio services.Over time, the nature of EMC considerations in the residential environment haschanged. The introduction of digital circuitry into appliance designs has addednarrowband, high frequency emissions to the possibility of broadband interferencefrom DC motors and electromechanical switches. Electromagnetic susceptibility hasbeen affected both by the use of potentially sensitive semiconductors in appliances,and by a residential environment that now includes many more disturbance sourcessuch as cell phones, portable phones, remote controls and home entertainmentelectronics. Electromagnetic Compatibility Electromagnetic emissions Electromagnetic 2
  • 47. Effects of EMC on Smart Appliance DesignsRegulatory requirementsBackgroundThe regulation of electromagnetic emissions started with commercial radiobroadcasting, so that interference with broadcast reception would be minimized. Inthe United States, the Federal Communications Commission (FCC) was established in1934 to regulate broadcasting and interference. In the same year, the German “High-frequency device law” was published. Spectrum regulators in other parts of the worldwere established around this same time to deal with the rapid growth of thebroadcast industry. To this day, emissions are regulated worldwide to preventinterference to radio and TV broadcasting, and sensitive services such as radionavigation and radio astronomy.Immediately after radio receivers found their way into automobiles in the 1930’s, thesubject of susceptibility arose – those receivers picked up interference fromautomotive ignitions and even static from the tires. Both sources of interference werequickly resolved, but the concept of EMC had been established. During the SecondWorld War, the dense packaging and high power of military electronics acceleratedthe development of standards for both emissions and susceptibility.Regulation of emissions from consumer devices grew mid-century with the advent ofelectrical household appliances and semiconductors, the latter enabling low-costwireless remote controls and portable telephones. The digital electronics contained inpersonal computers that became popular during the 1970’s was found to generatepotent radio interference. As a result, digital device regulations were establishedaround the world – in the USA under FCC Part 15 Subpart J in 1979, internationallyby the IEC standard CISPR 22 in 1985, and in the European Union under the EMCDirective in 1989.EMC regulations now play an essential part in both governmental and privatestandards – to prevent radio interference and assure equipment functionality inaerospace, automotive, commercial, medical, military and residential applications. Wewill explore how “smart” appliances pose unique EMC challenges for both design andregulatory compliance.EMCThe regulation of EMC varies around the world by product use and jurisdiction. In theUnited States of America (USA), only the emissions of residential and commercialappliances are specified – adequate levels of susceptibility or immunity are left to 3
  • 48. Effects of EMC on Smart Appliance Designsmarketplace to determine. Emissions-only regulations for residential and commercialproducts are also found in Australia, Canada, China and Japan. Some commonresidential and commercial emissions standards are listed in Table 1 below:Product type USA European Union InternationalHousehold appliances - EN 55014-1 CISPR 14-1Audio/visual, broadcast receiver 47 CFR Part 15 EN 55013 CISPR 13Information technology (ITE) 47 CFR Part 15 EN 55022 CISPR 22ISM (Industrial, Scientific, Medical)that generates radio-frequency 47 CFR Part 18 EN 55011 CISPR 11energyTable 1 – Common residential and commercial emissions standardsIn the European Union (EU), regulation of both emissions and immunity for residential,commercial and industrial products of all types is in force, to assure the freemovement of goods among member states. South Korea has also adopted the morecomprehensive approach of the EU. The most common residential and commercialsusceptibility/immunity standards are listed in Table 2 below:Disturbance type Common source European Union InternationalESD (Electrostatic Static buildup EN 61000-4-2 IEC 61000-4-2Discharge) Broadcast stations,Radio-frequency consumer wireless > 80 EN 61000-4-3 IEC 61000-4-3Radiated Immunity MHzEFT/B (Electrical Fast ac branch switch arcing EN 61000-4-4 IEC 61000-4-4Transient Burst)Surge Lightning-induced EN 61000-4-5 IEC 61000-4-5 Broadcast stations,Radio-frequency consumer wireless < 80 EN 61000-4-6 IEC 61000-4-6conducted Immunity MHzPower line magnetic ac power wiring EN 61000-4-8 IEC 61000-4-8immunityPower line variations Ac branch load switching EN 61000-4-11 IEC 61000-4-11Table 2 – Common residential and commercial immunity 4
  • 49. Effects of EMC on Smart Appliance DesignsEmissions - USA In the USA, the FCC exempts from its technical regulations appliances that contain “incidental radiators” such as switches and motors. Only appliances containing radio frequency (RF) or digital circuitry – defined as having clocks or oscillators operating above 9 kHz – fall under Part 15 rules, and even then there are additionalexemptions under which the digital circuitry in appliances may fall: • Power consumption below 6 nanowatts (nW); this would apply to most calculators and some digital clocks. • Battery-operated only, and having an operating frequency below 1.705 MHz. • Used exclusively in transportation vehicles; these are subject to other industry standards. • Digital devices used in large motor-driven appliances such as dishwashers and air conditioners.This last exemption to Part 15 regulation – digital circuitry used exclusively inappliances – was intended only for large appliances, but has been widelymisinterpreted to apply to all appliances. The FCC allowed the exemption on the basisthat their large motors effectively mask any emissions produced by the low frequencymicroprocessors they employ. There is no such basis for exempting a hair dryer, ricecooker or massager.Notwithstanding any or all of the exemptions listed above, the appliancemanufacturer is obliged to assure that his devices do not cause interference to radioor TV. FCC Part 15.103 states: The operator of the exempted device shall be required to stop operating the device upon a finding by the Commission or its representative that the device is causing harmful interference. Operation shall not resume until the condition causing the harmful interference has been corrected. Although not mandatory, it is strongly recommended that the manufacturer of an exempted device endeavor to have the device meet the specific technical standards in this part.The simplest way for the appliance manufacturer to comply with the intent of 15.103is to have the appliance tested for compliance with either the Class A (non-residentiallimits) or Class B (residential limits), if there is any possibility that the appliance may 5
  • 50. Effects of EMC on Smart Appliance Designs causing interference. Appliances intended for use in the home would, of course, be subject to Class B emission limits. Appliances that use RF energy to do some kind of work (such as heating or ionization) are subject to FCC Part 18 (ISM devices) rather than Part 15. Examples of such appliances are microwave ovens, wireless battery chargers and compact fluorescent lamps. The emission limits and measurement procedures under Part 18 are different from those of Part 15, and the product labeling is different too. FCC regulations for appliances are summarized in Table 3 below. FCC EMC regulations, appliances: emissions immunity example no digital circuitry n/a* n/a hair dryer with digital circuitry 15 subpart B** n/a setback thermostat with ISM function Part 18 n/a microwave oven wireless charger RF lighting * but cannot cause interference. ** only large appliances are exempt.Table 3 - FCC regulations applicable to appliances in the USA FCC rules, including Parts 15 and 18, are available online at: Emissions - Japan As with the FCC in the USA, residential appliances intended for use in Japan are subject to compliance only with emission requirements; susceptibility is not regulated but is left to the marketplace. Self-declaration of conformity to the Electrical Appliance and Material Safety Law ("DENAN") is appropriate for most electrical appliances. Transition deadlines of March 31, 2006 to March 31, 2011 from the prior Material Control Law to the present DENAN are largely past. The emission limits are drawn from IEC CISPR standards and are summarized in Table 4. 6
  • 51. Effects of EMC on Smart Appliance DesignsJapan EMC regulations, appliances: emissions immunity exampleno digital circuitry CISPR n/a hair dryer 14:1993/A1:1996audio-visual CISPR n/a CD player 13:1996/A1:1998with digital circuitry CISPR n/a computer 22:1993/A1:1995with ISM function High-frequency n/a microwave oven appliances (ISM)Table 4 - EMC regulations applicable to appliances in JapanAppliances in Japan are not subject to the low-frequency harmonics (EN/IEC 61000-3-2) and flicker (EN/IEC 61000-3-2) emission limits that apply in the EU. These standardsare discussed more fully in the EU section below.Emissions - Australia Australia does not impose susceptibility or immunity requirements under its EMC Framework. Rather, the Australian Communications and Media Authority (ACMA) recognizes a wide variety of joint Australian/New Zealand (AS/NZS), IEC, CISPR and CENELEC standards for self-declaration and C-tick marking connoting EMC compliance. Earlier versions ofstandards are superseded on clearly-defined dates posted on ACMA’s EMC StandardsList at AS/NZS CISPR 14.1(appliances emissions) and AS/NZS 61000.6.3 (generic) are the most appropriatestandards for compliance, as well as AS/NZS CISPR 22. As with Japan, appliances inAustralia and New Zealand are not subject to the low-frequency harmonics (EN/IEC61000-3-2) and flicker (EN/IEC 61000-3-2) emission limits that apply in the 7
  • 52. Effects of EMC on Smart Appliance DesignsDesigns for emissions compliance“Smart” appliances will contain some digital circuitry. The key design features to meetemissions compliance are:For AC conducted compliance: • consider bypass capacitors across the ac line, or a modular line filter for more severe noise • use a common-mode choke to attenuate higher frequency conducted emissions. • assure that any third-party switching power supplies already meet emission limitsFor RF radiated emission compliance: • use the lowest-power and slowest speed logic circuitry possible • keep the circuit layout as compact as possible • physically separate clock/driver circuits from I/O circuits as much as possible • use capacitive bypassing or ferrite beads on lines leaving the circuit board • use the appliance enclosure for shielding or signal grounding, if it is metallic • for non-metallic enclosures, use an internal shield for severe interferenceEmissions and Susceptibility - EU In the European Union, both appliance emissions and susceptibility or immunity are regulated under the EMC Directive 2004/108/EC for the purpose of CE-marking by “harmonized” standards that are listed periodically by the European Commission at: standards are drawn largely from those published by the EuropeanOrganization for Electrical Standardization CENELEC. It should be noted that thesestandards are not mandatory, but if they are used to demonstrate compliance thenconformity is presumed.The EMC Directive and its official interpretations allow many fewer exemptions thanFCC rules, but appliances that contain inherently “benign” components do not needto be tested. Such “benign” components include passive resistance loads, acinduction motors, simple quartz watches, incandescent lamps, home and 8
  • 53. Effects of EMC on Smart Appliance Designsswitches that do not contain any active electronic components and passive antennasused for TV and radio broadcast reception.The harmonized emission and immunity standards in the EU that are commonlyapplied to appliances are shown in Table 5 below.RF interference and immunity, EU appliances emissions immunity examplegeneral EN 55014-1 EN 55014-2 hair dryer EN 61000-3-2 EN 61000-3-3with ISM function EN 55011 EN 55014-2 microwave oven EN 61000-3-2 EN 61000-3-3with digital function EN 55014-1 EN 55014-2 setback thermostat EN 61000-3-2 EN 61000-3-3Table 5 - CENELEC standards applicable to appliances in the EUThe emissions standard EN 55014-1 requires ac conducted measurements similar toFCC Part 15, EN 55011 and EN 55022. However, it uses as a proxy for radiatedemission measurement above 30 MHz an absorbing clamp or ferrite transformer thatis moved along each appliance cable, including the ac power cable. Use of theabsorbing clamp to measure disturbance power is predicated on the assumption thatmost of the radiated interference from appliances smaller than 1m on a sidepropagates along its cables and not out from the enclosure.Appliance measurements using the absorbing clamp are further detailed in the IECstandard CISPR 16-2-3. The method is quicker than radiated emissions measurements,and the test site requirements are also simpler. A diagram of disturbance poweremissions measurement on an appliance using the absorbing clamp is shown in Fig. 9
  • 54. Effects of EMC on Smart Appliance DesignsFigure 1 – Absorbing clamp used to measure appliance emissions.The emissions standard EN 55014-1 allows for the possibility of digital circuitry in the“smart” appliance, but the possibility of digital emissions above 300 MHz is notforeseen in the standard. It does include radiated emissions limits and methods, butonly for toys.If the appliance contains sources of emissions above 300 MHz, not necessarily a“smart” appliance but more likely in that case than otherwise, it is prudent to includeEMC testing to a radiated emissions standard in addition to EN 55014-1. Reasonablechoices would be either EN 55022 (for information technology equipment) or EN61000-6-3 (generic emissions for residential, commercial and light industrialenvironments – the radiated emission limits are identical to EN 55022).Several years ago a British importer of hair dryers was fined£6000 because two hair dryers, when tested for complianceto the “essential requirements” of the EMC Directive, failedthe disturbance power limits of EN 55014-1 by up to 8 dB,but they also failed generic radiated emission limits by 19 dB.The hair dryers also caused visible interference to TVreception. Many in the EMC community at this time weresurprised that the UK authorities chose to apply an EMC test(radiated emissions) over and above the appropriate productfamily standard EN 55014-1 for the hair dryers. The 10
  • 55. Effects of EMC on Smart Appliance Designsauthorities considered that EN 55014-1 was not sufficient. Therefore, carefulconsideration needs to be given to the appropriate EMC testing of “smart” appliancesthat are likely to generate high-frequency emissions.Designs for disturbance power complianceThe absorbing clamp used to measure disturbance power is sensing common-modesignals in the cable being tested. In order to reduce these common-mode signals: • consider bypass capacitors across the ac line, or a modular line filter for more severe noise • use ferrite beads or common-mode chokes on signal lines • for any shielded (screened) cables, minimize the impedance between cable shield and appliance enclosure or ground; improve termination of cable shield to connector, and connector to appliance enclosure or ground.Harmonic and flicker emissionsTable 5 contains references to the low-frequency (< 2 kHz) standards EN 61000-3-2(harmonic emissions) and EN 61000-3-3 (flicker emissions). These standards only applyto equipment in the EU drawing less than 16 A/phase. Related standards coverequipment with higher current consumption. EN 61000-3-2 and EN 61000-3-3 areso-called “horizontal standards,” in that they apply to all types of equipment withintheir scopes, including home appliances, in addition to other EMC standards.Harmonic emissions occur when the appliance power supply imposes a distortedcurrent waveform onto the ac line, typically through diode rectification or electronicswitching. The effect of high harmonic emissions is not so much the disturbance ofother equipment connected to the same ac line, but rather the potential foroverheating of a branch circuit feeding other equipment that also generates harmonicemissions. EN 61000-3-2 specifies that appliances drawing less than 75 W areexempt, from testing, and that “professional” equipment rated above 1 kW is alsoexempt.Flicker emissions occur when the appliance presents a slowly- and quickly-varying load to the ac line. Limits are based on the threshold of annoyingflicker caused by a 60 W incandescent lamp connected to the same acbranch as the appliance. Note that flicker emissions are not regulated inthe EU on the basis of disturbance to other appliances, but rather on theirritability to bystanders. EN 61000-3-3 specifies that tests need not bemade on equipment which is unlikely to produce significant voltage fluctuations 11
  • 56. Effects of EMC on Smart Appliance DesignsIn the example of a setback thermostat in Table 3, testing to neither EN 61000-3-2nor EN 61000-3-3 would be applied, because either: (a) the thermostat is battery-powered and not connected to the ac line, or (b) if ac-powered it consumes less than75 W and by itself is unlikely to produce significant flicker emissions.Designs for harmonic and flicker emissions complianceFor harmonic emissions compliance: • do not use a linear ac power supply > 75 W; use a power-factor-corrected (PFC) switching supply.For flicker emissions compliance: • use solid-state and soft-start techniques for switching loads • where real loads must be switched on and off, consider transferring to equivalent dummy loads.Appliance susceptibility and EN 55014-2The harmonized product family standard EN 55014-2 draws on most of the commonEMC disturbance tests and applies them selectively, depending on the technology inthe appliance. Four categories are defined, as shown in Table 6 below: Category I Category II Category III Category IV Electronic control No electronic Battery-powered, circuitry circuitry, clocks < Everything else control circuitry clocks < 15 MHz 15 MHz Tools, Motor-operated examples Electronic toys thermostats appliances, toysTable 6 – Appliance categories defined in EN 12
  • 57. Effects of EMC on Smart Appliance DesignsBased on these categories, EN 55014-2 then defines which disturbance phenomenaare to be applied to the appliance during testing, which performance criteria must bemet, and the levels of the disturbances. The tests to be applied by category are shownin Table 7 below: disturbance Category I Category II Category III Category IV B (C, some ESD n/a B toys) B RF radiated n/a n/a A A EFT/B n/a B n/a B Surge n/a B n/a B RF conducted n/a A (230) n/a A (80) Mains variations n/a C n/a CTable 7 – Applicability of susceptibility tests by appliance categoryIf the appliance contains no electronic control circuitry, no disturbances are applied.The appliance is deemed to comply without testing. The performance criteria are: A - performs as intended during and after test A (80) - criterion A, with upper limit of testing 80 MHz. A (230) - criterion B, with upper limit of testing 230 MHz. B - may degrade during test, returns to normal after test. C - test may cause loss of function, which may be self-recoverable or by operator actionExamples of permissible degradations in performance, in terms of measurableappliance parameters such as speed, torque, etc. are also given in EN 13
  • 58. Effects of EMC on Smart Appliance DesignsThe reference standards and test levels specified in EN 55014-2 are given in Table 8below:EMC disturbance reference standard test levelESD EN 61000-4-2 4 kV contact, 8 kV airRF radiated EN 61000-4-3 3 V/m. 80% modulatedEFT/B transients EN 61000-4-4 0.5 kV signal lines, 1 kV ac linesSurge EN 61000-4-5 1 kV differential, 2 kV common modeRF conducted EN 61000-4-6 1 V signal lines, 3 V ac linesMains variations EN 61000-4-11 100% interrupt, 0.01s; 60% dip, 0.2s; 30% dip, 1s.Table 8 – Overview of EN 55014-2 EMC tests and levelsJust as we saw with the appliance emissions standard EN 55014-1, when “smart”functions are added to the appliance, additional susceptibility tests to those listedabove may be needed to assure reliable operation and compliance with the essentialrequirements of the EMC Directive.Designs for susceptibility/immunity complianceESD • for metallic enclosures, assure good contact all along seams • for non-conductive enclosures, assure no gaps • keep sensitive wiring away from conductive enclosure • provide capacitive bypassing and clamping components for wiring entering circuit boardsRF radiated • use metallic enclosure for shielding, or provide internal shielding • provide ferrite beads and/or capacitive bypassing for sensitive wiring on or entering circuit board • keep circuit wiring and boards as short as possibleEFT/B • use capacitive bypassing or modular filter on ac power entry and cables > 3m • place bypassing or filtering of ac power entry as close as possible to enclosure boundary • use capacitive bypassing or ferrite beads on internal wiring that is 14
  • 59. Effects of EMC on Smart Appliance DesignsSurge • use capacitive bypassing or modular filter on ac power entry • use clamping components at power entry, to limit surge energyRF conducted • use capacitive bypassing or modular filter on ac power entry and cables > 3mMains variations • assure adequate frequency response and energy storage in power supplyCommunicationsOne way to enhance the functionality of home appliances is to endow them with thecapability of communicating with a home computer, phone line or each other. Thedesigner’s choice of whether radio or powerline communications is the medium isconstrained by the performance characteristics of each and national regulations thatvary from place to place. In any case, it is usually possible to embed an approved orcompliant communications module into the appliance, minimizing the design timeand regulatory compliance effort. There are often additional EMC or radio testsnecessary to assure compliance of the “smart” appliance with the installedcommunications module.Powerline communicationsPower wiring is everywhere in the home, and products have been developed to use itas a communications bus. However, the ac wiring generally carries a great deal ofinduced noise from network switching equipment, other home appliances andelectronics and radio transmitting sources that couple into the wiring. As a result,reliable powerline communications (PLC) with the home typically use robust encodingsuch as spread spectrum technology to superimpose control or data signals on the acline. Industry standards govern the signaling protocols, but regulatory compliance fallsunder spectrum regulators such as the FCC.In the USA, home powerline communications falls under the Part 15 category ofcarrier current systems. They are regarded as “unintentional radiators” subject to therules in 15.109(a), (e), and (g) and the general radiated emission limits in 15.209. TheFCC’s Class B radiated emission limits can be used to assess compliance of an installedsystem, or CISPR 22 Class B as an FCC-accepted alternative. The only ac conductedemission limit is 1000µV (60 dBµV) over the AM broadcast frequency range 535 –1705 kHz. There are no regulatory compliance requirements for susceptibility 15
  • 60. Effects of EMC on Smart Appliance DesignsIn Canada, residential and office powerline communications are regulated under ICES-006. For systems operating above 1.705 MHz the radiated emission limits are identicalto FCC limits. However, below 535 kHz ICES-006 imposes limits on carrier currentoutput voltages that do not exist in FCC rules. Both the FCC and Industry Canadarequire verification of carrier current systems in three separate locations.The regulatory situation for powerline communications in the EU presently divides atthe signaling frequency of 148.5 kHz. Harmonized standards exist for both emissionsand susceptibility below that frequency, but for broadband powerlinecommunications above 1 MHz only an immunity standard is available as shown inTable 9 below:Signaling range Harmonized emissions standard Harmonized immunity standard95 – 148.5 kHz EN 50065-1 EN 50065-2-11.6 – 30 MHz none EN 50412-2-1Table 9 – EU powerline communications standardsEN 50065-1 is a complex emissions standard that divides the operating range 95 –148.kHz into several sub bands, two of which require a signaling protocol. Thus it islimited to low-frequency control and data applications.While the European Commission has emphasized that all such systems must meet theessential requirements of the EMC Directive, little guidance is available on how to dothat for systems operating above 1 MHz. Amendments to CISPR 22 are underway toaccommodate higher levels of conducted emissions for PLC systems than thoseallowed by the present ac conducted limits.RadioFor the “smart” appliance designer looking at wireless communications, there areseveral system architectures of interest: Short/medium range low-power radio link(s) appliance-to-appliance or appliance- to-PC Long range low-power radio link(s) in appliance(s) to public telephone (PSTN) gateway low-power radio link(s) in appliance(s) to PC-to-Internet low-power radio link(s) in appliance(s) to cellular modem in PC or freestanding cellular modem(s) in appliance(s) 16
  • 61. Effects of EMC on Smart Appliance DesignsBy exploiting the use of a PSTN or Internet gateway,wireless links (and also powerline buses) allow appliancesto be interrogated by the owner at any location over asecure path; or permit the appliance to report impendingor actual failure modes to a central repair facility; or to beshut down by the local utility over a “smart grid” to reducepeak demand or take advantage of off-peak pricing.If powerline communications is hampered by differing national regulations, radiocommunications is similarly burdened, except that: • there are a few short-range radio bands available more-or-less globally, such as 2.4 GHz (including such IEEE 802 protocols as Bluetooth, Wi-Fi and Zigbee) • embedded cellular modems are available to individually satisfy most national spectrum allocationsSome generally available wireless frequency bands and regulations are listed in Table10 belowFrequency band FCC Industry Canada EULow-power, short distance (1 – 10m)433.92 MHz 15.231* RSS-210 A.1* EN 300 2202.45 GHz 15.249 RSS-210 A2.9 EN 300 440Low-power, medium range (10 – 100m) high-speed data2.45 GHz 15.247 RSS-210 A.8 EN 300 328 EN 300 4405 GHz 15.401 A.9 EN 301 893* Protocol requirements on type of communication and transmission rate.Table 10 – A sample of wireless regulations for common frequency bandsThe corresponding standards for some public telephone (PSTN) interfaces are: FCC 47 CFR Part 68, TIA-968-B Canada CS-03 EU ES 203 021-1, -2 and -3Under the EU Radio and Telecom Terminal Equipment (RTTE) Directive 1999/5/EC, theonly essential requirements for terminal interfaces are EMC and safety. Therefore theETSI ES standards listed above are discretionary but recommended. For a 17
  • 62. Effects of EMC on Smart Appliance Designsterminal interface in the EU the typical mandatory standards would be EN 55022(emissions) and EN 55024 (immunity) and EN 60950-1 (safety).The essential requirements for radio equipment under the RTTE Directive includeEMC, safety and spectrum protection. Therefore in addition to the spectrumstandards listed in Table 10 for the EU, there are these additional EMC standards: Spectrum standard EMC standards EN 300 220, EN 300 440 EN 301 489-1, -3 EN 300 328 EN 301 489-1, -17 EN 301 893 EN 301 489-1, -17EN 301 489-1 is the core EU EMC standard for radio equipment that definesapplicable EMC tests by equipment type, and performance criteria. The EMC tests arelargely those listed in Tables 1 and 2 above. The EMC standards EN 301 489-3 and -17 apply specific setup and operating conditions appropriate to the frequency bandand equipment.There are no susceptibility/immunity requirements under FCC rules for the wirelessbands above.Designs for communications compliance • Assure that transmitter modules are already certified for the jurisdiction; “compliant with” is not the same as “certified.” • Appliances containing cellular modems will generally require approval by the cellular network operator, in addition to modem certification. • Use the transmitter module in accordance with any user guidance or certification conditions; antenna choices may be restricted. • Exercise care in selecting operating frequency bands; there are very few bands that are acceptable worldwide. On the other hand, a region-specific band may be less subject to interference than a more popular global one.Product safetyAppliance safety standards concern the hazards of shock, fire, heating, and similarphysical phenomena. “Smart” appliances present no unusual EMC hazards except infour categories: 1. wireless appliances that can be used during life safety emergencies; related safety standards generally contain additional tests to assure the integrity of the wireless 18
  • 63. Effects of EMC on Smart Appliance Designs 2. appliances for use in the EU that can generate strong and potentially hazardous low-frequency electromagnetic fields. 3. “smart” appliances with embedded radios, where the combination of radiofrequency output power and proximity to the user is potentially hazardous. 4. “smart” appliances that use electronic circuitry for safety-critical functions such as motion or power shutoff.Category 4 is addressed in the section below on Functional safety, and categories 2and 3 are addressed in the section below on Electromagnetic exposure.Functional safetyThe IEC standard series IEC 62508-1…-7 is directed at the structures for defining andreducing the hazards and risks associated with electrical/electronic/programmableelectronic (E/E/PE) safety-related systems. The impact of functional safety on EMC isperhaps best captured in IEC 51508-2 clause, bold added: e) the electromagnetic immunity limits (see IEC 61000-1-1) which are required to achieve electromagnetic compatibility – the electromagnetic immunity limits should be derived taking into account both the electromagnetic environment (see IEC 61000-2-5) and the required safety integrity levels; NOTE 1: It is important to recognize that the safety integrity level is a factor in determining electromagnetic immunity limits, especially since the level of electromagnetic disturbance in the environment is subject to a statistical distribution. …For higher safety integrity levels it may be necessary to have a higher level of confidence, which means that the margin by which the immunity limit exceeds the compatibility level should be greater for higher safety integrity levels.Thus the susceptibility/immunity levels specified in Tables 5, 7, 8 and 9 above may notbe sufficient for safety-related functions implemented in “smart” appliances. The IEC61508 series provides guidance for evaluating and designing to the appropriaterequirements.Electromagnetic exposureStrictly speaking, EMC refers to the harmonious operations of equipment with eachother in the context of an electromagnetic environment. In many cases persons arepart of that environment, and consideration must be given for “smart” appliances toany adverse effect of electromagnetic exposure on users and operators of thatequipment. The nature of any electromagnetic threat varies by disturbance frequency,from skin surface currents at very low frequencies to cell heating at frequencies in theMHz and GHz 19
  • 64. Effects of EMC on Smart Appliance DesignsNational regulations for electromagnetic exposure generally divideby considering whether the exposure results as a natural byproductof the operation of the appliance (such as a heating blanket) orwhether there is an intentional radiating source of radio frequency(RF) energy present (radio transmitter). Table 11 details this division. USA EU Microwave ovens: 21 CFR 1030: EU CouncilElectromagnetic Leakage limit 1 mW/cm2 new, 5 Recommendationfields (EMF) as a mW/cm2 afterward. 1999/519/EC; harmonizedbyproduct of Otherwise: only guidelines (IEEE standard EN 50366 fornormal operation C95.1) appliances. EU Council 47CFR 1.1310, 2.1091, 2.1093.Radiated fields Recommendation SAR evaluation for userproduced 1999/519/EC; harmonized distances < 20 cm.intentionally for standards for radios such as MPE evaluation for usercommunications EN 50360, EN 50371, EN distances > 20 cm 50385Table 11 – Overview of USA and EU regulations for electromagnetic exposureIn practice, appliance EMF evaluation under EN 50366 in the EU is limited tofrequencies below 400 kHz and therefore considers low-frequency effects. Radiatedfields from transmitters in the USA, EU and many jurisdictions elsewhere are typicallyevaluated above 300 MHz, and involve high-frequency effects.EU low-frequency EMF limits: EN 50366The test procedures in EN 50366 measure magnetic flux density emanating from theappliance over the range 10 Hz to 400 kHz. The magnetic flux density limit at 50 Hz is100 microTeslas (µT). For comparison, the earth’s magnetic field generates a steady-state or DC magnetic flux density from 30 µT to 60 µT.The measurement distances for evaluation differ according to the typical separationbetween the appliance and the user, as in Table 12 below:Measurement Appliance typedistance, cm 0 Electric blanket, dental hygiene, hair clipper, indoor whirlpool bath 10 Facial sauna, hair dryer, water bed heater 30 Dishwasher, washing machine, hand tool, microwave oven, 20
  • 65. Effects of EMC on Smart Appliance Designs refrigerator 50 Air conditioning unit, heater, clock, vacuum cleanerTable 12 – measurement distances in EN 50366 for evaluation of EMFCompliance with EN 50366 is mandatory for appliances to meet CE-markingrequirements for safety. There are no corresponding requirements in the USA.Designs for EMF complianceAppliances with motors; working at high frequencies to 400 kHz; working with veryhigh currents; evaluated at 0 cm • Assure adequate magnetic shielding; twist or shield ac power feed and internal wiringRF exposure from radiosOwing to the popularity of cell phones, Bluetooth, Wi-Fi and other wireless devices,there are concerns about the health effects of such radios in close proximity to theuser. Many jurisdictions have RF exposure rules for transmitters in place, including theUSA, Canada, the EU, and Australia. Most of the rules are based on the heating effectof the RF energy on human cells, as the RF energy is non-ionizing and no otherpotential sources of cell damage have been conclusively observed.The method of evaluation of RF exposure from a radio transmitter depends on itstypical proximity to the user or others nearby. The information in Table 13 below is forUS parameters but other jurisdictions are 21
  • 66. Effects of EMC on Smart Appliance DesignsUser Evaluation type methoddistance 1. Appliance with transmitter is placed near the body simulator filled with fluid approximating dielectric properties of brain or muscle. 2. Electric field inside body simulator is scanned to Specific determine maximum power density or SAR from< 20 cm Absorption Rate transmitter outside. (SAR) 3. SAR limits do not vary with frequency, but with body part exposed. Hands, wrists and legs can dissipate heat better than head or body and have higher SAR limits. 1. RF power to antenna is measured. Maximum 2. Gain of antenna is considered to calculate maximum> 20 cm Permissible power density at 20 cm or larger user distance. Exposure (MPE) 3. MPE limits vary with RF frequency.Table 13 – RF exposure evaluation of appliances containing radio transmittersThe graphical results of a typical SAR scan on a cellular handset are shown in Figure 2below. Note that the place of highest SAR is at the base of the handset antenna:Figure 2 – SAR scan of a cellular 22
  • 67. Effects of EMC on Smart Appliance DesignsIn most regulatory regimes, average transmitter powers of 20 mW or less do notrequire SAR evaluation regardless of the user distance. Transmitter power above 0.6W approaches the upper limits of SAR for head-held devices such as cellular handsets.Transmitters operating > 20 cm from users (and most installations in fixed applianceswould fall in this category) would meet FCC 1.1310 MPE limits with 1 W poweroutput and no antenna gain (0 dBi) from 30 to 300 MHz. Allowed power to meetMPE limits rises to 5 W from 300 to 1500 MHz and remains flat at 5 W above 1500MHz. These power levels are reduced if the antenna gain is greater than 0 dBi.Designs for RF exposure compliance • Use the lowest transmitter power consistent with reliable operation • Multiple radio transmitter modules in one appliance may require additional RF exposure evaluation For more information on specific testing and certification information, please contact Intertek at 1-800-WORLDLAB, email, or visit our website at publication is copyright Intertek and may not be reproduced or transmitted in any form in whole or in part without the priorwritten permission of Intertek. While due care has been taken during the preparation of this document, Intertek cannot be heldresponsible for the accuracy of the information herein or for any consequence arising from it. Clients are encouraged to seekIntertek’s current advice on their specific needs before acting upon any of the 23
  • 68. Automotive EMC Testing 12, 600 sq.ft. facility. Expanded performance, vibration and EMC test capabilities and test equipment. AEMCLAP Accreditations BCI ESD (Closed Loop/Substitution Method) ISO 10605 GMW3100/3097 para. SAE J1113-13 GMW3097 Feb04 3.4.1 GMW3100/3097 para. ISO 11452-4 GMW3097 Feb04 3.6 SAE J1113-4 Ford ES-XW-7T-1A278-AC Ford ES-XW-7T-1A278-AC Chrysler DC 106141 Chrysler DC 106141 Radiated Emissions Radiated Immunity CISPR 25 (ALSE) SAE J1113-41 ISO 11452-2 GMW3100/3097 para. SAE J1113-21 GMW3097 Feb04 3.3.1 GMW3100/3097 para. Ford ES-XW-7T-1A278-AC GMW3097 Feb04 3.4.2 Chrysler DC 106141 Ford ES-XW-7T-1A278-AC Chrysler DC 106141 Service Features: • Fast report turn around - Raw data available within 24 hours of test completion. Report available in 48 hours. • Secure Website - Clients will be provided with a secure Website where data and reports will be posted for their convenience. • Remote monitoring - We will provide a method of monitoring tests based on the clients needs: -VHS -DVD -Live Webcam EMC Testing: • SAE J1113-4 Conducted Immunity (BCI) • SAE J1113-11 Immunity to Conducted Transients on Power Leads • SAE J1113-12 Electrical Interference by Conduction and Coupling • SAE J1113-13 Immunity to Electrostatic Discharge • SAE J1113-22 Immunity to Radiated Magnetic Fields from Power Lines • SAE J1113-41 Test Limits and Methods of Measurement of Radio Disturbance Characteristics from Vehicle Components and Modules • SAE J1113-42 Conducted Transient Emissions • SAE J551 • OEM Specific Requirements as well, including GMW3100 GS, Nissan 28400 NDS, Mazda MES PA 66920 • ISO 7637 Series (-1, 2, 3) Electrical disturbance by conduction and coupling • ISO 11452-4 Bulk Current Injection (BCI) • ISO 11452-2 Radiated RF Immunity (ALSE) • ISO 10605 Electrostatic Discharge (ESD) • European Directive 2004/104/EC Emissions Tests: • Radiated Emissions • CISPR 25, Nissan, Ford, ISO, SAE, Fiat, Audi, GM, Chrysler, Honda and many others • Use R+S Receiver ESIB 40 with low loss cables • AEMCLAP Certified measurements in our 5m Anechoic Chamber from 10 kHz to 40 GHz • Conductive / Non-conductive table top • AEMCLAP Certified Site • 8 diameter turntable capable of handling 5000 lbs. Max. Line Conducted Emissions • Horizontal and Vertical ground planes/5m Chamber7/06
  • 69. Immunity Tests: Environmental Testing: • Temp / Humidity Chambers — Electrostatic Discharge (ESD) 27 cubic feet; fully programmable 3°C/min ramp rates • +/- 15 kV Contact Discharge, +/- 30 kV Air Discharge. • Thermal Aging • Humidity & Temperature controlled rooms and lab. • Thermal Cycling • Waveform verification target with 1 GHz Oscilloscope. • Thermal Shock– 16 cu. Ft. each chamber, • Various ESD tips from standard IEC/EN test to tips designed for automotive. 3 chambers (2-hot, 1-cold), chamber to chamber transfer time <5sec. Bulk Current Injection (BCI) - Temperature Range Hot Chamber: 71°C • Use of dual directional power meter and probes for Forward, Reverse and to 210°C (160°F to 375°F) Net power measurements for every test. - Cold Chamber: -75°C to 190°C • Fixtures specifically designed per standards to improve repeatability (-103°F to 375°F) • Specific equipment per standard used for testing to ensure proper testing - Refrigeration: 25 to 30 horsepower and repeatability • Can perform testing to Ford, GM, Chrysler, Fiat, Nissan, Honda, Mazda, Audi, 5m EMC Chamber ISO or any other BCI standard. Specifications Radiated Electromagnetic Fields (RF) • Certified from 10 kHz - 40GHz • Tested in new 5m chamber. • Radiated Immunity from 80MHz - 18GHz • Uniform field per IEC/EN specification. @ 200 V/m CW • Varity of modulations (AM, FM, Pulsed) • Calibrated Uniform field all 16 points from 26MHz - 18GHz • Field strengths designed for >600 V/m at a distance of 1m CW or pulsed from 1-18GHz • Radiated Emissions capable of 3m and 5m measurements • Calibrated fields available up to 18 GHz • Interior working dimensions of 30.1 feet - 1kW amplifier from 80 MHz- 1 GHz x 18.1 feet x 18 feet - 250W amplifiers from 1 GHz - 18 GHz • Shielding performance greater than 100dB from 1kHz - 40GHz - 500W amplifier from 10 kHz - 200 MHz • 2m diameter turntable rated for 8,000 lbs • Floor rating of 8,500 lbs/sq ft or a total load capacity of over 10,000 lbs Frequency Ranges Field Strength V/m Antenna • Hydraulic lift capacity of over 10,000 lbs 10 kHz to 30 MHz >200 E Field (between elements) • Isolated shielded support room for clients support equipment 30 MHz to 2 GHz >200 Bi Log @ 1m distance • Separate shielded control room and isolated shielded amplifier room. 200 MHz to 18 GHz >200 Horn @ 1m distance • 8 foot by 8 foot door opening • Meets and exceeds requirements for 16 different standards. • CISPR 25 ground studs 90cm off floor • 5M EMC Chamber— Capabilities from 26 MHz to 18GHz. Can be used for testing in accordance to: SAE, ISO, GM, Ford, Chrysler, Nissan, Audi, Fiat, • Air pressure @ 300PSI Honda, Mazda, CISPR 25,11,16,22, SAE J1113, SAE J551 • Water/ Drain available @ street pressure • Typical industry standards include Automotive, GM 5097, 3100, DC • 200V/m fiber optic CCTV (Have access to viewing the product with a 10614REV A, Ford AB/AC, Nissan, Mazda, Fiat, Honda, Audi, Chrysler, SAE, fiber optic camera system that shows no effect due to the high field ISO, Mazda strength produced) • Peripheral support utilities are available: Compressed air (125 PSI @ • Fiber optically controlled mast and turntable 30 CFM, oiled or purified @ 2 Microns), Water (to 100 PSI), External gas • Automated Radiated Immunity and Radiated Emissions testing capability venting (200 CFM), AC Power up to 240 VAC @ 50 Amps (50 or 60 Hz) single or three phase, DC Power up to 65 VDC @ 150 Amps. Full color Available power internal monitoring system, with multiple camera angles provided. • 100 amps @ 120VAC 60 Hz single phase Generators, Chillers, Power Loads, Inert Gases, EMC hardened computers, • 100 amps @ 208VAC 60 Hz three phase can be made available. • 30 amps @ VARIABLE DC power • EUT (equipment under test) can be either tabletop or floor standing equipment. • 30 amps @ VARIABLE AC power • 30 amps @ 480VAC 60 Hz three phase • 30 amps @ 230VAC 60 Hz single phase All power is independently filtered.1/10 ©2010 Intertek Intertek 1-800-WORLDLAB w w w. i n t e r t e k . c o m
  • 70. The Ongoing Challenges inAutomotive EMC Compliance Intertek 70 Codman Hill Road Boxborough, MA 01719 800-WORLDLAB
  • 71. The Ongoing Challenges in Automotive EMC ComplianceContents Introduction ..............................................................................................2 History .......................................................................................................3 The Changing EMC Environment.............................................................3 Changing EMC Test Requirements ..........................................................6 Summary ...................................................................................................7 1
  • 72. The Ongoing Challenges in Automotive EMC ComplianceIntroductionWith advances in technology over the last decade, customer demand and OEMcompetition has forced automakers to try to integrate many of the latesttechnologies into their vehicles. Many of these technological advances, whetherentertainment, communication or performance improvements, do succeed inbringing to the consumer a new level of comfort and convenience as well asenhanced safety features. But along with these features come new challenges toensure EMC (Electromagnetic Compatibility) and device interoperability within thevehicle. EMC issues can result in minor annoyances such as unwanted noise throughthe entertainment system, as well as major issues such as loss of engine functions orcontrol issues that could compromise the safety of drivers, passengers and thepublic. Add to this the growing demand of Hybrid Electric Vehicles (HEV) andElectric Vehicles (EV). These systems may bring a whole new set of concerns inrelation to EMC. For these reasons, EMC is and will continue to be a very importanttopic of concern for the automakers’ present and future.There are two opposing forces at work influencing EMC in the vehicularenvironment. 1) The growing number of electronic components and modules forcontrol, communications, and entertainment now being installed make achievingEMC far more demanding. 2) The force promising to bring the situation undercontrol is the trend to replace complex vehicle wiring carrying analog, digital, andhigh-current signals with simpler, low-power signaling protocols.Between these two forces, engineers are modifying their predictive tools to keep upwith changes at all levels – integrated circuit EMC evaluation, module EMCprediction and measurement, and whole vehicle characterization. As circuits operateat higher frequencies (and voltages), simulation methods have to adopt smallergrids for the accurate prediction of the resulting electromagnetic fields.As this process of modification is underway, the vehicle manufacturers need toassure that new modules have been tested to their respective EMC standardscorrectly and that the standards reflect the actual environment of future installation.While many vehicle EMC standards are non-governmental (and/or OEM specific)and therefore simpler to update, in the EU the Automotive EMC Directive2004/104/EC contains its own requirements and is therefore more cumbersome toamend. Fortunately, it contains a number of international EMC standard references.With the recent surge of public awareness for a need for alternative vehicles such asEV’s and HEV’s , there are more independent auto manufacturers on the scene andthey are starting to review their own EMC procedures and may see themselvesdeveloping their own standards based on their findings and business growth. 2
  • 73. The Ongoing Challenges in Automotive EMC ComplianceHistoryThe popularization of the car radio in the late 1920s was the “canary in the coalmine” — the proverbial early warning— that automotive EMC would be anongoing challenge. By the 1930s, a number of commercial radio brands wereavailable. The early models were AM (amplitude modulation) only and verysusceptible to both ignition noise and static buildup from the car’s tires. Bothsources of disturbances were quickly overcome. Spark plug suppression wasprovided by resistive cables and resistive plugs; research on optimum spark plugsuppression continued into the 1970s1. Conductive carbon was added to the cartires to prevent electrostatic charge buildup. In 1947, SAE J551, the first SAE(Society of Automotive Engineers) EMC standard, was published, but it was notuntil the proliferation of vehicular electronics in the 1970s that development offurther vehicle EMC standards occurred.The Changing EMC EnvironmentToday’s motor car contains an amalgam of legacy electrical/electronic functions andmore recent devices – literally dozens of components or modules, sensors andactuators, and more than one network. Table 1 below lists typical functions andtheir attributes. function history attributesAirbag deployment Existing CriticalBraking control Existing Critical Comfort, Radio Noise, gage/warningCabin environment Existing functionCollision avoidance New Likely unlicensed radar 77 GHz.Communications New Cellular, Bluetooth (800, 1900, 2400 GHz)system Environmental and legal concerns in someEmissions control Existing statesEngine ignition Existing Critical May include satellite radio receiver, FMEntertainment system New modulator (low power 88-108 MHz).Fuel injection Existing Critical1 “Relationship Between Spark Plugs and Engine-Radiated Electromagnetic Interference,” IEEETransactions on Electromagnetic Compatibility, Burgett et. al.,August 1974, pp. 160-172. 3
  • 74. The Ongoing Challenges in Automotive EMC ComplianceLighting system New Some Xenon discharge lamps.Navigation system New GPS receiverNoise cancellation New ComfortSeat and pedal position Existing Critical Short-range and Part 90 radio (170-300Security system Existing MHz)Stability control New CriticalTire pressure New Short-range radiomonitoringTransmission control Existing CriticalTable 1 Typical automotive electronic component or module functions.Each of these functions exists in, and impacts, the vehicle’s EMC environment. Forexample, all of the control systems add to network/bus noise. Also, thecommunications, entertainment and security systems introduce radio sources whilethe GPS (global positioning systems) and satellite radio receivers require very low RFnoise over their operating bands.Compounding these EMC challenges from the added electronic functions are thenew factors associated with Hybrid Electric Vehicles (HEVs) and Electric Vehicles(EVs). Specifically, these include bus voltages exceeding 200 V, power inverterswitching noise, and new bus/cable configurations. These issues are illustrated inthe propulsion system block diagrams in Figure 1 and 2 for HEV and EVconfigurations. 4
  • 75. The Ongoing Challenges in Automotive EMC Compliance transmission DC AC power High inverter voltage battery DC/DC 12V battery Electric motor Engine Figure 1 Simplified HEV (Hybrid Electric Vehicle) block diagram. DC Electronic High control voltage unit battery 12V battery Power inverters and motors Figure 2 Simplified EV (Electric Vehicle) block diagram.In addition to the basics shown in these figures, there are the myriad modules,sensors, actuators, networks, and central control for the vehicle. 5
  • 76. The Ongoing Challenges in Automotive EMC ComplianceChanging EMC Test RequirementsExisting EMC whole vehicle and module test standards cover the range ofelectromagnetic phenomena in conventional vehicles2. Vehicle manufacturers haveadopted SAE and international standards to varying degrees and have establishedtheir own EMC standards that the testing laboratory must follow closely. Table 2summarizes some of the relevant standards by reference number. A sample of automotive EMC standards parameter SAE GM Ford Toyota Int’lEMISSIONS CISPR TSC7026G 25 TSC7058G Radiated RF ES-XW2T- CISPR 25 J551/1, GMW3097 1A278-AC J551/5 Conducted RF CISPR 25 TSC7058G CISPR 25 CS-2009.1 Conducted J1113-42 _ ISO7637-2 transientRADIATED IMMUNITY J551/1, TSC7025G J551/12, ES-XW2T- ISO 11452-2, RF immunity J551/16, GMW3097 1A278-AC ISO 11452-3 J1113/28Magnetic field J551/17 CS-2009.1 TSC7001G immunity ISO 11452-8 J1113-22COUPLED TRANSIENTS Inductive J1113-12 ES-XW2T- TSC7001G coupled 1A278-AC transients GMW3097 ISO 7637-2 CS-2009.1CONDUCTED IMMUNITY Susceptibility J551/13 TSC7315G ISO 11452-4 J1113-2,3,4 ES-XW2T- J1113-11 GMW3097 1A278-AC TSC7001G ISO 7637-2, Transient ISO 7637-3 ESD J551/15 CS-2009.1 TSC7018G ISO 10605 J1113-132 “An Overview of Automotive EMC Standards, “Poul Anderson, IEEE EMC Symposium 2006 Proceedings, 2006,pp. 812-816. 6
  • 77. The Ongoing Challenges in Automotive EMC ComplianceDue to the high cost of performing whole-vehicle EMC testing and the need toexpedite component integration, EMC testing is being performed at both thecomponent or module and chip levels. The results are then used to predictcompliance of the whole vehicle. Even without the added complexities of new HEVand EV propulsion systems, there are difficulties inherent in the existing testmethods. At the chip or IC level, test standards such as IEC 61967-x family and SAEJ145 2/3 do not fully predict installed EMC. The correlation between near- and far-field emissions may not hold, and the result is highly dependent on any externalwiring harness. Also, at the module or component level, similar ambiguities exist.Component testing, however, can still be useful for identifying potential EMCproblems.The introduction of HEV and EV propulsion systems clearly intensifies the challengesto existing test methods even more. High battery voltages reduce powertransmission losses, but the resulting higher system impedances can render invalidemissions test results obtained with the artificial networks described in CISPR 253.Battery and drive motor impedance and impedance changes can also become animportant factor in EMC. Worst-case RF emissions from vehicular power convertershave been observed under transient conditions of load and speed4. Unfortunately,measurement standards have not yet taken this observation into account.SummaryThe automotive EMC environment is in a constant state of flux as new onboardelectric devices, communications media (both wired and wireless), and new drivesystems are added. Consequently, both EMC standards writers and vendors findthemselves in a situation without fixed, agreed-upon testing procedures for assuringthe compatibility of vehicles and components in hybrid and all electric cars.Ongoing change is the only constant. Automakers need to continue with strictattention to detail and try to model tests to capture the newer issues and concernsthey come across. Component suppliers need to be aware of these concerns duringtheir development cycles. Manufacturers of after market products and “cross over”devices, such as various kinds of IT equipment now being used in vehicles need tobe cognizant of the requirements of the automotive EMC environments.Although automotive EMC standards are well-established by manufacturers andboth domestic and international standards-making bodies, refinements may be3 “High Voltage Automotive EMC Component Measurements Using an Artificial Network,” Nelson et. al.,IEEEProceedings 18th Int. Zurich Symposium on EMC, 2007, pp. 195-200.4 “HEV System EMC Investigation during Transient Operations,” Nelson and Aidam, IEEE Proceedings 18th Int.Zurich Symposium on EMC, 2007, pp. 205-208. 7
  • 78. The Ongoing Challenges in Automotive EMC Complianceneeded to achieve better correlation between chip-level and component- ormodule-level measurements and whole vehicle testing. New HEV and EV drivesystems continue to add further challenge to automotive EMC testing.About IntertekAs a leading provider of quality safety solutions serving a wide range of industries around the world, Intertekhas the expertise, resources and global reach to support its customers through its network of more than 1,000laboratories and offices – 39 specializing in EMC testing – in more than 100 countries around the world.For more information regarding Intertek’s new developments, call 1-800-WORLDLAB or visit: www.intertek.comThis publication is copyright Intertek and may not be reproduced or transmitted in any form in whole or in part without the priorwritten permission of Intertek. While due care has been taken during the preparation of this document, Intertek cannot be heldresponsible for the accuracy of the information herein or for any consequence arising from it. Clients are encouraged to seek Intertek’scurrent advice on their specific needs before acting upon any of the content. 8
  • 79. EMC for Military & AerospaceSecure an efficient and cost-effective test partnerIntertek, a global leader in testing, inspection and certification,has completed significant upgrades to its ElectromagneticCompatibility Testing (EMC) labs to now perform mandatory EMCtesting to commercial, military and aerospace requirements. Weoffer complete service, from initial project tendering stage and testplan origination, through to pre-compliance testing and timely finalqualification report.Our responsive team of experienced engineers and projectsupport staff, are on-hand to advise, guide, and manage thewhole process on your behalf.We provide testing to MIL-STD 461, DO-160F and MIL-STD 810standards at various locations within North America and Europe.Intertek’s EMC testing facilities provide 10-meter and 5-metersemi-anechoic chambers to accommodate military products of allshapes and sizes. Our commitment to unrivaled service allowsproject completion within your target time-frames & smoothmarket entry. Qualified Professionals With over 25 years experience in military and aerospace testing, Intertek engineers have the knowledge and experience to understand your industry needs.
  • 80. Testing Capabilities MIL-STD 461 MIL-STD 810 • EMC Radiated Immunity • Materials Testing • EMC Radiated Emissions • Vibration • EMC Radiated Susceptibility • Thermal Shock • Bulk Current Injection • Electrical Testing • Conducted Immunity • Mechanical Testing • Conducted Emissions • Altitude • Conducted Susceptibility • Temperature • Humidity • Salt Fog/Spray MIL-STD 704 • Immersion(Aircraft Electric Power Characteristics) • DC-400 H2 • Normal and Abnormal Power DO-160 Supply Condition Simulations • Section 15 Magnetic Effect • Voltage Ranges: • Section 16 Power Input o AC Systems: 115V • Section 17 Voltage Spike o DC Systems: 28 to 270V • Section 18 Audio Frequency Conducted Susceptibility – Power Inputs MIL-STD 1179D • Section 19 Induced Signal(Lamps, Reflectors & associated SusceptibilitySignaling Equipment for Military Vehicles) • Section 20 RF Susceptibility (Conducted & Radiated) • Photometric Testing • Section 21 Emission of RF Energy • Color Testing • Section 22 Lightning Induced • Blackout Visibility Testing Transient Susceptibility • Section 25 ESD Sample Projects Federal Aviation Administration (FAA) R&D Performance Testing of Obstruction Lighting systems per FAA requirements in accordance with FAA Advisory Circulars. US Army RDECOM ACQ CTR Testing of Advanced Combat Helmet (ACH) for PM Soldier Equipment according to government regulations in three phases. MARCOSYSCOM Code GTES/PM Engineers Test for 3-Ton and 5-Ton capacity packaged Environmental Control Units (ECU) for the US Marine Corps Systems Command HVAC equipment. For more information on EMC testing and certification for Military & Aerospace industries, call 1-800-WORLDLAB or visit
  • 81. EMC Compliance for Renewable Resource Power Systems Intertek Testing Services 70 Codman Hill Road Boxborough, MA 01719 1-800-WORLD LAB
  • 82. EMC Compliance for Renewable Resource Power SystemsContents Introduction ..................................................................................................... 2 Renewable Resources ....................................................................................... 3 Biomass .................................................................................................... 3 Geothermal .............................................................................................. 4 Hydroelectric............................................................................................. 5 Solar energy.............................................................................................. 6 Photovoltaic (PV) ....................................................................................... 6 Concentrating solar power (CSP)............................................................... 7 Tidal power............................................................................................... 8 Wave power ............................................................................................. 8 Wind ........................................................................................................ 9 EMC Considerations....................................................................................... 10 Environments and Installations ................................................................ 10 Emissions ................................................................................................ 13 Susceptibility........................................................................................... 16 Powerline communications...................................................................... 18 Wireless communications ........................................................................ 19 Summary ....................................................................................................... 20 About Intertek.............................................................................................. 1
  • 83. EMC Compliance for Renewable Resource Power SystemsIntroductionRenewable resources such as plants, sunlight, wind, rain and geothermal heat arenaturally replenished over time – as distinguished from the finite resources coal, oiland natural gas. The market forces driving the development of renewableresources vary by region of the world, but they include: • Reduction of greenhouse gases; • Reliability of existing power network; • Depletion of petrochemical sources; • Local regulations, tariffs, subsidies and tax incentives.The scale of cost-effective power generation from renewable resources varies bytype, and it can range from small rooftop photovoltaic (PV) solar cell installationsgenerating a few kilowatts (kW) for local consumption (see photo below) to anoffshore wind farm producing hundreds of megawatts (MW) peak and distributedover the high-voltage electricity grid to thousands of users. Often, renewableresource utilities will use more than one technology, to assure a more uniformsupply of electric power over a 24 hour period.Not all renewable resources need to be convertedinto electrical power to be useful. For example,geothermal heat is widely used for both heatingand cooling on a local basis. Fluid-filled solarpanels can similarly provide home heating. Usingthe renewable resource to generate electricity,however, multiplies its versatility in terms ofapplications, customers served, and electricalutility power saved. In this paper we will focuson electricity generation using renewableresources.Each of these renewable resource electrical power systems has its own uniqueelectromagnetic compatibility (EMC) characteristics – RF emissions and immunity -in addition to issues of environmental and electrical safety. Most jurisdictionsaround the world (in the USA for example, the FCC) regulate radio interferencefrom electrical and electronic equipment, and many also govern immunity (as inthe EU) to assure that the equipment continues to operate as intended in thepresence of interference from other equipment including radio transmitters.Standards also cover EMC requirements for grid-connected or grid-tied powersources, where the renewable resource feeds electrical power back into the 2
  • 84. EMC Compliance for Renewable Resource Power Systems Renewable Resources Today, renewable resources account for about 18% of the global electricity generation market. Some segments such as PV and wind power are growing more rapidly than others, but all segments are experiencing substantial investment. Estimates of the present capacity and potential for renewable resources are given in Table 1 below, followed by a brief overview of the most common renewable sources of electrical power. Total global electricity consumption is estimated at 15 TW, which can be supplied many times over by only partial realization of renewable resources. 2010 generating capacity, Global generating potential, Renewable source Gigawatts (GW) Terawatts (TW)Biomass 54 46Geothermal 11 22Hydroelectricity 480 7Solar photovoltaic (PV) 21 1000Solar concentrated (CSP) 500Tidal power 50 MW 10Wave power 10 MW 2Wind 175 72 Table 1 – Estimated global capacity and potential for renewable resource electricity generation. Biomass The term biomass includes fuels derived from timber, agriculture and food processing wastes or from fuel crops that are specifically grown or reserved for electricity generation. Biomass fuel can also include sewage sludge and animal manure. Biomass can be converted into other forms of energy through chemical processes such as fermentation, but for the purpose of electricity generation direct combustion is generally used. Some air pollution can be created, so biomass power plants may be less “green” than other renewable resources. Biomass is widely used for individual heating and cooking. It is estimated that 40% of the world’s cooking stoves use biomass. However, biomass power plants are typically utility-scale (output > 200 kW) and are not suitable for individual residential use. The photo at left depicts a 24 MW plant. Steam-electric generators, also used in fossil fuel power plants, provide the electrical power output 3
  • 85. EMC Compliance for Renewable Resource Power Systemsfrom biomass plants. Although the power plants themselves are exempt from mostEMC regulatory requirements (except to not cause interference), their internalcontrol equipment performs critical functions that demand adequate immunityfrom industrial electromagnetic disturbances. The electrical output of the plantmust conform to utility standards for power quality. Figure 1 illustrates a typicalplant block diagram.GeothermalHot springs, geysers and ancient Roman baths are all examples of geothermalenergy. This energy source can be tapped directly for individual residentialpurposes without generating electricity, by using heat pumps. At the utility level,geothermal power plants convert hydrothermal fluids (hot water or steam) toelectricity. The oldest type of geothermal power plant uses steam, accessedthrough deep wells, to directly drive a turbine to produce electricity. Flash steamplants are the most common type of geothermal power plants in operation today.They use extremely hot water (above 300 degrees F), which is pumped under highpressure to the generation equipment at the surface. The hot water is vaporizedand the vapor in turn drivesturbines to generate electricity.Binary-cycle geothermal powerplants use moderate-temperaturewater (100-300 degrees F). Thewater is used to vaporize a secondfluid that has a much lower boilingpoint than water. The vapor fromthis second fluid is then used todrive the turbines to produceelectricity.As with biomass generating plants, the geothermal power plants themselves areexempt from most EMC regulatory requirements; their internal control equipmentperforms critical functions that demand adequate immunity from industrialelectromagnetic disturbances. The electrical output of the plant must conform toutility standards for power quality. Figure 1 below illustrates a typical plant 4
  • 86. EMC Compliance for Renewable Resource Power SystemsHydroelectricMany hydroelectric power plants use a dam on a river to store water. Waterreleased from behind the dam flows downhill through a turbine, spinning it, whichthen turns a generator to produce electricity. Hydroelectric power does not requirea large dam – some hydroelectric power plants use only a small channel to directthe river water through a turbine. A small or micro-hydroelectric power system (<100 kW) can produce enough electricity for a home or farm. Water is 800 timesdenser than air, so it is a very efficient source of power where it is available.Small or micro-hydroelectric plants are often used off-grid, where the power willbe consumed locally. DC generators or alternators can be used where AC powerfrequency is unimportant. If the hydro power is to be fed back into the utility grid,or otherwise where line frequency is critical, then the power plant mustincorporate any of: 1) an automatic controller at its inlet valve plus an alternator,or 2) an induction generator synchronized to the utility power, or 3) a solid-stateinverter accepting either DC or variable-frequency AC and synchronized to theutility power.The control systems in small or micro-hydroelectric installations may be subject toresidential or commercial electromagnetic emissions limits, as well as immunity.Grid-connected or grid-tied systems are subject to utility power qualityrequirements. Large hydroelectric plants will generally be exempt from EMCstandards, but their internal control systems must meet industrial EMC standardsin order to provide adequate operating 5
  • 87. EMC Compliance for Renewable Resource Power SystemsHydroelectric storage – pumping water uphill for later release – is often used inconjunction with renewable resources that are periodic in nature, such as solar, inorder to provide a more uniform flow of electrical power to the user.Solar energyAround the world, several kilowatt-hours per day of solar energy fall on everysquare meter on the surface of the earth. The exact amount depends on latitudeand weather, but the total constitutes vastly more power than that presentlyconsumed.The conversion of solar power into useful energy usually takes one of two paths:1) direct use by heating, either locally with fluid-filled solar panels or at utility scaleby concentrating solar power (CSP or solar thermal); or 2) using siliconphotovoltaic (PV) panels to generate DC electricity either for residential purposesor at utility scale. The DC power is usually converted to AC power using solid-stateinverters. Inverters are available with capacities ranging from a few kW forresidential applications to MW for utility plants. Large-scale CSP is more efficientthan PV at converting solar energy to electricity, but the difference is diminishingas solar cell technology advances.Photovoltaic (PV): A number of different silicon fabrication technologies (such asthin film, monocrystalline silicon, polycrystalline silicon, and amorphous) are usedin assembling panels to convert solar energy to DC electrical power. The current- voltage characteristics of each panel are a function of the incident solar energy, with output short circuit current and open circuit voltage increasing with increasing light level. Maximum power is derived from each panel when the product of voltage and current outputs are maximized. Most inverters intended for PV applications will have built-in power maximization circuitry. Most residential and utility scale solar PVinstallations (such as the megawatt-scale installation shown above) keep theirpanels in a fixed orientation for the sake of simplicity, even though tracking theposition of the sun can add up to 50% in 6
  • 88. EMC Compliance for Renewable Resource Power SystemsThe control systems and inverters in residential or small commercial PV systems aresubject to residential or commercial electromagnetic emissions limits, as well asimmunity requirements. Grid-connected or grid-tied systems must meet utilitypower quality requirements. Large PV plants will generally be exempt from EMCstandards, but their internal control systems and inverters must meet industrialEMC standards in order to provide adequate operating reliability. Solid-state DC-to-AC inverters employ high-power switching circuitry, which can generateradiated and conducted interference unless adequately shielded and filtered.Concentrating solar power (CSP) or solar thermal: Concentrating solar power(CSP) technology is used solely in utility scale plants. It works by capturing the solarenergy with a number of concentrating mirrors or lenses, and uses the resultingheat to create steam and then electricity by a turbine generator. The mostcommon forms for concentrating thesun’s energy are linear solar troughs(parabolic in cross-section), solardishes (similar to satellite dishes) andsolar towers surrounded by a field ofreflectors called heliostats as in thephoto here. Temperatures of up to1,500˚C may be generated in anintermediate heat transfer workingfluid that may be oil or molten salts,and finally into steam for the turbine. Molten salts have the added advantage ofstoring heat to generate steam during cloudy weather or at night.Figure 1 also serves as the block diagram for the power generation part of CSPsystems. The trough reflectors, dishes, heliostats and lenses used in CSP 7
  • 89. EMC Compliance for Renewable Resource Power Systemstrack the position of the sun during the day, to maximize solar power conversion.This adds some complexity to the overall system. CSP plants will generally beexempt from EMC standards, but their internal control and tracking systems mustmeet industrial EMC standards in order to provide adequate operating reliability.Tidal powerOwing to the gravitational pulls of the earth’s moon and sun, ocean tides flowtwice a day in and out of natural estuaries or man-made channels. This flow of water can be harnessed by submerged turbines similar to wind turbines as a reliable source of electrical energy. Although a number of tidal power prototypes have been deployed, this is a relatively new technology and only one tidal power system, shown in the illustration at left, has been deployed commercially in the UK. The system can generate up to 1.2 MW of power; rotor blade angle control allows the system to generate regulated AC power for tidal flow in both directions. Tidal power plants themselves are exempt from most EMC regulatory requirements; their internal control equipment performs critical functions thatdemand adequate immunity from marine electromagnetic disturbances, includingshipboard radars. The electrical output of the plant must conform to utilitystandards for power quality.Wave powerIt has been estimated that favorable coastal locations contain about 50 kW permeter of shoreline in available wave energy. This energy is not as steady orpredictable as tidal power; in fact, it hasmany of the same characteristics as windpower. A number of different approacheshave been tried to harness wave power,but few have been commercialized so far.One method employs a float inside abuoy that moves up and down with thewaves, working an internal plunger that isconnected to a hydraulic pump. Thepump drives a generator to produceelectricity, which is sent to the shore by means of an undersea cable.Owing to the variability of the power source, wind power systems are often grid-connected through a solid-state inverter that can assure constant AC frequencyand waveform. Wave power plants themselves would be exempt from most 8
  • 90. EMC Compliance for Renewable Resource Power Systemsregulatory requirements; any internal control equipment would need adequateimmunity from marine electromagnetic disturbances, including shipboard radars iflocated far offshore. The electrical output of the plant would have to conform toutility standards for power quality.WindWind power is similar to PV solar power in being available everywhere, and inbeing scalable from individual residential wind turbines at the kW level to utilityplants generating 100 MW or more. The offshore wind farm at left can generate300 MW, and includes its own offshore power substation. A typical individualwind turbine will include a rotor, gearbox and generator. The gearbox is used to increase the slow rotational speed of the rotor to higher generator speeds suitable for providing AC line frequency power from an induction generator. Electronic rotor pitch control is often used, especially in large-scale systems, to optimize power generation efficiency and provide speed reduction and stopping under very high winds and for servicing. Single residential or farm turbines mayuse a DC generator or alternator for battery recharging, or with a solid-stateinverter for grid-tied or grid-connected power feeding. Typical wind power systemsare shown in the block diagram in Figure 4 below.The aggregated power from utility scale wind farms is converted to HV fortransmission over the utility’s HV (> 100 kV) 9
  • 91. EMC Compliance for Renewable Resource Power SystemsThe control systems and inverters in residential or small commercial wind powersystems are subject to residential or commercial electromagnetic emissions limits,as well as immunity requirements. Grid-connected or grid-tied systems must meetutility power quality requirements. Large wind farms will generally be exempt fromEMC standards, but their internal control systems and inverters must meetindustrial (or marine, if located offshore) EMC standards in order to provideadequate operating reliability. Solid-state DC-to-AC inverters employ high-powerswitching circuitry, which can generate radiated and conducted interference unlessadequately shielded and filtered.EMC ConsiderationsEnvironments and InstallationsIn the USA, electromagnetic emissions are regulated by the FederalCommunications Commission (FCC) in order to prevent interference to radio andTV broadcast reception, and to sensitive services such as radio astronomy andradio navigation. Susceptibility is not regulated by the FCC – but there are medical, military, aerospace, automotive and some other industry standards. In the EU, both emissions and susceptibility are regulated under the EMC Directive 2004/108/EC to assure the free movement of goods.Typical EMC environments can be classified by the severity of the electromagneticdisturbances normally found there (for susceptibility), and by the distance to theboundary within the operator’s jurisdiction (for emissions). • Residential environments usually assume a boundary 10m away, and by household sources of disturbances. In the USA, residential emissions from RF and digital devices are regulated under FCC Part 15, Subpart B, Class B limits. In the EU, residential EMC requirements also extend to commercial and light industrial environments. Thus a home rooftop solar PV system containing electronics such as a solid state inverter falls under residential emission limits. • Industrial environments are generally based on a 30m boundary, and have disturbances from high-power switchgear, arc welding equipment and similar electromagnetically-noisy sources. In addition, industrial environments are often differentiated from residential ones in being connected to a medium-voltage (MV) power transformer as opposed to a 120/240 V low-voltage (LV) distribution transformer. In the USA, industrial emissions from RF and digital devices are regulated under FCC Part 15, Subpart B, Class A 10
  • 92. EMC Compliance for Renewable Resource Power SystemsWhen electrical or electronic equipment is located in a large area under onejurisdiction, such as in a public utility or industrial plant, most interferenceproblems from the equipment can be resolved within the area and withoutregulatory intervention. Hence the FCC exempts such equipment from its technicalrules. The corresponding classification under the EMC Directive in the EU is a“fixed installation” to which CE-marking does not apply. Utility-scale biomass,CSP, geothermal and PV plants are not subject to FCC or EU EMC limits except forthe general requirement to not cause interference. However, the controlequipment within these plants performs critical functions and should conform toappropriate industrial EMC standards such as EN/IEC 60947-1 (low-voltageswitchgear and controlgear) EN/IEC 61326-1 (process control and measurement),or IEC TS 61000-6-5 (immunity for power station and substation environments).The potential electromagnetic interactions between devices in an installation andwith external influences are indicated in Figure 5 below. Disturbances can enterand exit equipment by way of AC or DC power wiring, or over signal and controlcables. Radio frequency (RF) emissions can emanate from equipment enclosuresand disturb nearby equipment, or exit the installation boundary to causeinterference to radio/TV or other sensitive receivers not under the control of therenewable power system operator. Similarly, RF emissions from powerful broadcaststations or nearby cell phones can upset the monitoring or control systems of therenewable power system. When the components of a renewable power system(such as Unit 1 and Unit 2 in the figure below) do not interfere with each other,they are termed electromagnetically self-compatible. Figure 5 – Potential electromagnetic interactions between equipment and 11
  • 93. EMC Compliance for Renewable Resource Power Systems Table 2 below summarizes electronic equipment EMC standards for various environments for the USA and EU. Note that the scopes of US Class A and B emissions do not map directly onto the generic EU EMC scopes. Because renewable power systems generally include a variety of electronics that could fall under several different EU EMC standards, we have chosen to show the default or generic standards here. USA - FCC EU – EMC Directive Environment emissions only emissions immunityresidential Part 15 Class Bcommercial EN 61000-6-3 (generic) EN 61000-6-1 (generic)light industrial Part 15 Class Aindustrial EN 61000-6-4 (generic) EN 61000-6-2 (generic)public utility or Documentation of EMC No interference No interferenceindustrial plant considerations Table 2 – EMC standards for US and EU environments. Renewable power systems that are connected to the electricity grid, whether residential or industrial, are subject to additional EMC requirements to assure that the grid is not exposed to needless distortion or interference. In the USA, UL 1741 applies to inverters, converters, controllers and interconnection system equipment for use with distributed energy resources such as small-scale photovoltaic and wind power systems. When these systems are grid- tied or grid-connected, UL 1741 specifies compliance with the requirements in IEEE 1547 (Interconnecting Distributed Resources with Electric Power Systems), which in turn calls out these susceptibility standards: • IEEE Std. 37.90.2 (Withstand Capability of Relay Systems to Radiated Electromagnetic Interference from Transceivers); and • IEEE Std. C62.41.2 (Recommended Practice on Characterization of Surges in Low-Voltage AC Power Circuits); • Or, in place of C62.41.2, IEEE Std. 37.90.1 (Surge Withstand Capability Tests for Relays and Relay Systems Associated with Electric Power Apparatus); and • IEEE Std. 62.45 (Recommended Practice on Surge Testing for Equipment Connected to Low-Voltage AC Power Circuits). The net effect of these susceptibility standards is to impose EMC criteria similar to, and slightly more stringent than, EU EMC requirements for similar phenomena. For 12
  • 94. EMC Compliance for Renewable Resource Power Systemsexample, IEEE Std. 37.90.2 specifies a 20 V/m RF radiated immunity test, plus akeyed and 200 Hz modulated spot test, to simulate GSM cell phone effects. Thecomparable EU generic industrial susceptibility level is 10 V/m.In the EU, EN 50178 applies to all types of electronic equipment for use in powerinstallations. Internally it refers to the generic residential, commercial and lightindustrial or industrial EMC standards comparable to those in Table 2. EN 50178 isharmonized to the Low Voltage Directive 2006/95/EC but not the EMC Directive.EN/IEC 61727 covers the utility interface characteristics of photovoltaic systems; itapplies the flicker emission standards EN/IEC 61000-3-3 (< 16 A/phase) or EN/IEC61000-3-11 (> 16 A/phase) to the interface, plus current distortion limits that fallunder the category of EMC phenomena. EN 61727 is not harmonized orassociated with any EU directive.EmissionsElectromagnetic emissions may be intentional or unintentional. Intentionalemissions include radio signals from broadcast stations, cell phones, and remotecontrol keys; or signals over power lines to control lights and appliances.Unintentional emissions can arise from sources such as DC motor brush noise,electromechanical switching or digital circuitry in computers and power systems.Separate emissions standards apply to intentional and unintentional radiators.Induction motors and generators do not generate significant emissions, nor arethey susceptible to most electromagnetic disturbances. Therefore, they are usuallynot a factor in renewable power system EMC considerations. The major sources ofunintentional emissions in most renewable power systems are digital controlelectronics and solid state inverters. Both of these create emissions by rapidlyswitching internal currents. High harmonics of the fundamental switchingfrequencies are generated, up to tens or hundreds of megahertz.The inverter functions by chopping its input current into a series of pulses of variable width (pulse width modulation, or PWM), where the width changes to approximate a power frequency sine wave, as in Figure 6. The pulse frequency is often in the range 15 – 20 kHz. The input current to the inverter may be d.c., as for a photovoltaic installation, or ac for a wind turbine. If it is ac, the current is first rectified and then chopped.Figure 6 – Inverter switching waveform and output currentThe high-frequency energy created by the chopping process, as well as the residualnoise superimposed on the output current, must be adequately filtered to 13
  • 95. EMC Compliance for Renewable Resource Power Systemsexcessive conducted and radiated emissions. EMC-compliant inverters usuallycontain robust EMI filters at their inputs, outputs and any signal or controlconnections. They are also well-shielded and employ other good EMC designpractices.Any rapid change in electrical current can give rise to an electromagnetic emission.If the current is traveling over a circuit board trace or wire of suitable length, thatconductor can act as an antenna and radiate interference into the surroundingspace. Long cables such as power cords are efficient antennas for frequenciesbelow 30 MHz, so RF interference below 30 MHz is generally measured directly atthe cable port as a conducted emissions voltage. RF interference above 30 MHz isusually measured with an antenna as electric field strength. Equipment that canradiate strong magnetic fields below 30 MHz, such as Industrial, Scientific andMedical (ISM) devices, are also tested for RF interference using a magnetic loopantenna. The corresponding ISM emissions standards are FCC Part 18, EN 55011and CISPR 11.The regulatory emission limits of FCC Part 15 and the EU generic emission limitsare similar but not identical, as Tables 3. 4 and 5 below indicate. Key differencesbetween the US and EU requirements are: • The EU radiated emission limits are specified only up to 1 GHz; US limits can extend above 1 GHz, depending on the maximum frequency in the test item. Nevertheless, if a device in the EU can emit interference above 1 GHz, the EMC Directive requires additional testing. • FCC and EU environment definitions are not identical (see Table 2). • The EU generic standards specify measurement of telecom port emissions, and EN 61000-6-3 requires flicker and harmonic emissions. FCC Part 15 does not specify these. • The EU generic standards include the measurement of impulse noise (clicks) more frequent than 5 per minute. These are not measured under FCC Part 14
  • 96. EMC Compliance for Renewable Resource Power Systems measurement FCC Part 15 Class A EU EN 61000-6-4 industrial 30-88 MHz 39 dBµV/m 30-230 MHz 40 dBµV/m 88-216 MHz 43.5 dBµV/mRadiated emissions @ 10m 216-960 MHz 46.4 dBµV/m 230-1000 MHz 47 dBµV/m Above 960 MHz 49.5 dBµV/m 0.15-0.5 MHz 79 dBµV QP 0.15-0.5 MHz 79 dBµV QPConducted emissions 66 dBµV AV 66 dBµV AVon ac power port 0.5-30 MHz 73 dBµV QP 0.5-30 MHz 73 dBµV QP 60 dBµV AV 60 dBµV AV 0.15-0.5 MHz 97-87 dBµV QP 84-74 dBµV AVConducted emissions 0.5-30 MHz 87 dBµV QP No requirementon telecommunications port 74 dBµV AV 43 dBµA QP 30 dBµA AV Table 3 – Comparison of FCC and EU generic industrial emission limits. QP = Quasi-peak detector, AV = Average detector. Radiated emission measurements below 1 GHz use a QP detector. measurement FCC Part 15 Class B EU EN 61000-6-3 residential 30-88 MHz 29.5 dBµV/m 30-230 MHz 30 dBµV/m 88-216 MHz 33 dBµV/mRadiated emissions @ 10m 216-960 MHz 35.6 dBµV/m 230-1000 MHz 37 dBµV/m Above 960 MHz 43.5 dBµV/m 0-2 kHz No requirement 0-2 kHz rated current < 16A harmonics IEC 61000-3-2 flicker IEC 61000-3-3 rated current > 16A harmonics IEC 61000-3-12 flicker IEC 61000-3-11Conducted emissions 0.15-0.5 MHz 66-56 dBµV QP 0.15-0.5 MHz 66-56 dBµV QPon ac power port 56-46 dBµV AV 56-46 dBµV AV 0.5-5 MHz 56 dBµV QP 0.5-5 MHz 56 dBµV QP 46 dBµV AV 46 dBµV AV 5-30 MHz 60 dBµV QP 5-30 MHz 60 dBµV QP 50 dBµV AV 50 dBµV AV Table 4 – Comparison of FCC and EU generic residential emission limits. QP = Quasi-peak detector, AV = Average detector. Radiated emission measurements below 1 GHz use a QP detector. 15
  • 97. EMC Compliance for Renewable Resource Power Systems measurement FCC Part 15 Class B EU EN 61000-6-3 residential 0.15-0.5 MHz 79 dBµV QPConducted emissions 66 dBµV AV No requirementon dc power port 0.5-30 MHz 73 dBµV QP 60 dBµV AV 0.15-0.5 MHz 84-74 dBµV QP 74-64 dBµV AVConducted emissions 0.5-30 MHz 74 dBµV QP No requirementon telecommunications port 64 dBµV AV 30 dBµA QP 20 dBµA AV Table 5 – EU generic residential emission limits where there is no corresponding FCC Part 15 requirement. QP = Quasi-peak detector, AV = Average detector. Susceptibility EN 61000-6-1 (residential, commercial and light industrial environments) and EN 61000- 6-2 (industrial environments) apply to all types of power installations and equipment in the EU. In the USA, IEEE 1547 for distributed power resources contains several of the same types of EMC disturbances as the EU standards. Common sources for these disturbances are noted in Table 6, and a comparison of the susceptibility tests is given in Table 7 below. disturbance Typical source of disturbance Test standardsElectrostatic discharge (ESD) Static buildup on persons IEC 61000-4-2 IEC 61000-4-3, IEEERadiated electric field Broadcast stations, cell phones C37.90.2Electric fast transient bursts Power line switching transients IEC 61000-4-4 IEC 61000-4-5, IEEESurge Lightning-induced power line transient C62.41.2RF common mode voltage Low-frequency radio stations IEC 61000-4-6Power line magnetic field Nearby power line wiring IEC 61000-4-8Power line dips and Power line load variations and switching IEC 61000-4-11variations Power line switching and lightning-induced IEC 61000-4-12, IEEERing wave transients C62.41.2 Table 6 – Common electromagnetic disturbances and their corresponding test standards. 16
  • 98. EMC Compliance for Renewable Resource Power Systems Maximum disturbance amplitude in standard below disturbance reference IEEE 1547 EN 61000-6-1 EN 61000-6-2 industrial residentialElectrostatic 4 kV contact, 8 kV IEC 61000-4-2 X 4 kV contact, 8 kV airdischarge (ESD) air 3 V/m, 80-1000 10 V/m, 80-1000 MHz, MHz and 1.4-2.7 3 V/m, 1.4-2 GHz, IEC 61000-4-3 X GHz, 80% 1 V/m, 2-2.7 GHz,Radiated electric modulated at 1 kHz 80% modulated at 1 kHzfield 20 V/m, 80-1000 MHz, 80% modulated at 1 kHz; IEEE C37.90.2 X X 20 V/m at 900 MHz, 200 Hz on-off modulationElectric fast 1 kV pulses at 5 IEC 61000-4-4 X 2 kV pulses at 5 kHztransient bursts kHz IEC 61000-4-5 X 2 kV, 1.2 x 50 µs 2 kV, 1.2 x 50 µsSurge IEEE C62.41.2 6 kV, 1.2 x 50 µs X X 3 V, 0.15-80 MHz, 10 V, 0.15-47, 68-80 MHz;RF common mode IEC 61000-4-6 X 80% modulated at 3 V/m, 47-68 MHz,voltage 1 kHz 80% modulated at 1 kHzPower line IEC 61000-4-8 X 3 A/m 30 A/mmagnetic field 100% dip for 0.5, 1 cycle; 100% dip for 1 cycle;Power line dips IEC 61000-4- 30% dip for 25/30 30% dip for 25/30 cycles; Xand dropouts 11 cycles; 60% dip for 10/12 cycles; dropout for dropout for 250/300 cycles 250/300 cycles X IEC 61000-4- (2.5 kV at 1 MHz in IEC TS X XRing wave 12 61000-6-5 for power stations) IEEE C62.41.2 6 kV at 100 kHz X X Table 7 – Comparison of susceptibility or immunity tests for US grid-connected distributed power systems (IEEE 1547) and EU generic EMC standards which apply to both grid-connected and independent power equipment. The testing specified in Table 7 under IEEE 1547 bears no relationship to any FCC EMC requirements; these are given in Tables 3 and 4. Rather, IEEE 1547 is requisite for product safety listing or certification under UL 1741 (covering inverters, converters, controllers and interconnection system equipment for use with distributed energy resources). By contrast, the generic EU EMC requirements EN 17
  • 99. EMC Compliance for Renewable Resource Power Systems61000-6-1, -2, -3 and -4 are harmonized to the EMC Directive and complianceprovides a regulatory presumption of conformity. The EU harmonized safetystandard corresponding approximately to UL 1741 is EN 50178.Powerline communicationsIn addition to the unintentional electromagneticdisturbances on ac power lines noted in Table 6, electricutility companies have for decades superimposed low-frequency signals on their medium voltage (~ 10-40 kV)and low voltage (< 1 kV)distribution lines for networkmonitoring and control. More recently, both utilitiesand subscribers are using power lines at highfrequencies for Internet communications. These added signals may not beanticipated by common conducted susceptibility standards, so the grid-connectedrenewable resource equipment vendor needs to confirm functionality for thesesignals - whether or not the technology is being employed internally.Low-frequency signaling over power lines by power utilities has long beenpermitted in both the USA and EU. In the USA, such power line communications(or PLC) are regulated on a non-interference basis by the FCC under Part 15,section 15.113. The span may not include the subscriber or house wiring. Theavailable operating frequency band is 9 – 490 kHz. In the EU, the availablefrequency band is 3 – 95 kHz and the corresponding harmonized EMC standardsare:EN 50065-1 Signaling on low-voltage electrical installations in the frequency range3 kHz to 148.5 kHz - Part 1: General requirements, frequency bands andelectromagnetic disturbances. The maximum applied voltage limit is 134 dBµV or 5V. The emission limits above 150 kHz are identical to those in EN 61000-6-3 (Table4).EN 50065-2-3 Signaling on low-voltage electrical installations in the frequencyrange 3 kHz to 148.5 kHz -- Part 2-3: Immunity requirements for mainscommunications equipment and systems operating in the range of frequencies 3kHz to 95 kHz and intended for use by electricity suppliers and distributors. Theimmunity test levels are similar to those in EN 61000-6-3 (Table 7), except that themagnetic immunity test level increases to 100 A/m.There are also harmonized susceptibility test standards for non-utility signalingover power lines: EN 50065-2-1 (residential, commercial and light industrialenvironments) and EN 50065-2-2 (industrial environments). These parallel thegeneric standards shown in Table 18
  • 100. EMC Compliance for Renewable Resource Power SystemsMore recently, high-frequency signaling has been permitted over both utilitydistribution lines and domestic power wiring. The FCC rules governing RFemissions from utility-controlled medium-voltage (MV) and low-voltage (LV) linesare found in FCC Part 15 Subpart G for “Access Broadband over Power Line” orAccess BPL, in the frequency band 1.705 – 80 MHz. The FCC limits addressradiated emissions only, and use Part 15 Class A limits for MV systems and Part 15Class B for LV systems. There are no FCC equipment susceptibility requirements.Acceptance of high-frequency or broadband over powerline communications inthe EU has been impeded by the absence of any harmonized emissions standardsthat allow practical system operation. Emissions standards such as EN 55022, EN61000-6-3 and -4 contain ac conducted limits that are too low to be useful.Nevertheless, a harmonized immunity standard has been published:EN 50412-2-1 Power line communication apparatus and systems used in low-voltage installations in the frequency range 1.6 MHz to 30 MHz -- Part 2-1:Residential, commercial and industrial environment - Immunity requirementsThe susceptibility or immunity levels required in this standard agree with the levelsshown in Table 7 for both residential and industrial environments.In the USA, grid-connected renewable power systems such as distributed PV orwind power should target compliance with the most stringent combination of IEEE1547 and EU generic EMC standards for the intended environment. Theequipment should provide adequate filtering against any powerline carrier signalsthat may be in use, or – if the system is intended to respond to such signals -carefully route the signals only to intended receivers. If the renewable powersystem generates powerline carrier signals, self-compatibility must be assured.Wireless communicationsProduct EMC standards such as EN/IEC 60947-1(low-voltage switchgear and controlgear) andEN/IEC 61326-1 (process control andmeasurement) provide generally adequate RFimmunity from common radio transmitters asAM/FM/TV broadcast, cell phones, walkie-talkies and remote controls. Similarly,renewable resource systems comprising anumber of different equipment types andevaluated to the requirements of the generic EMC standards EN/IEC 61000-6-1and -2 will afford protection from performance degradation in the presence ofmost common RF interference 19
  • 101. EMC Compliance for Renewable Resource Power SystemsAdditional EMC considerations may come into play when either the operatingenvironment of the renewable power system or specific equipment configurationsresult in RF fields higher than those in the relevant EMC standards. For example:The system is deployed in a navigable waterway and may be exposed to shipboardradar (> 1 GHz) or low-frequency radio communications fields (0.1 – 27.5 MHz);The power system contains a radio telemetry or voice communications transmitterantenna in close proximity to other electronics;Operating and maintenance personnel are using handheld two-way radios whileworking in open cabinet enclosures.In each of these cases the potential maximum RF field should be compared withthe tested immunity limits of the power system and its electronic components.SummaryRenewable resource power systems contain the promise of environmentalfriendliness and petrochemical independence. In many parts of the world, suchpower systems are being encouraged by tax incentives and simplified regulation.Each type of resource considered here –biomass, geothermal, hydroelectric,photovoltaic, tidal, wave and wind – has itsown advantages and drawbacks. Some,such as PV and wind, are well-suited toresidential or distributed configurations. All,even the largest utility-grade power systems,are subject to EMC considerations for thesake of either regulatory compliance,reliable operation, or both.EMC regulations for renewable resourcepower systems vary widely around the world,but the US FCC and EU EMC regulations are fairly representative so they areexamined here. The FCC does not generally regulate susceptibility or immunity ofelectronic equipment, but for grid-connected resources in the USA immunity isnecessary for product safety listing or certification. In the EU, both grid-connectedand independent power systems must meet EMC 20
  • 102. EMC Compliance for Renewable Resource Power SystemsAbout Intertek -- Commercial & ElectricalIntertek Commercial & Electrical Services specialize in testing and certification for a wide range of products,including household appliances, electronics, automotive components, heating equipment and air conditioning,cable and wiring accessories, industrial machinery, medical equipment, lighting, semiconductors andmanufacturing products for construction. We provide industry-specific certification services forelectromagnetic (EMC) compatibility and specialized telecommunications.This publication is copyright Intertek and may not be reproduced or transmitted in any form in whole or in partwithout the prior written permission of Intertek. While due care has been taken during the preparation of thisdocument, Intertek cannot be held responsible for the accuracy of the information herein or for any consequencearising from it. Clients are encouraged to seek Intertek’s current advice on their specific needs before acting upon anyof the 21