• Share
  • Email
  • Embed
  • Like
  • Save
  • Private Content
Electrical Commissioning and Arc-Flash Safety presentation
 

Electrical Commissioning and Arc-Flash Safety presentation

on

  • 275 views

Electrical Commissioning and Arc Flash Safety training presentation given November 21, 2013. Mike Luffred presented this information as a technical seminar for the National Capital Chapter region ...

Electrical Commissioning and Arc Flash Safety training presentation given November 21, 2013. Mike Luffred presented this information as a technical seminar for the National Capital Chapter region (PA/NJ/DE/VA/MD/DC) of the Building Commissioning Association. The presentation was given at the Eaton Experience Center in Warrendale, PA to help commissioning engineers understand the importance of arc flash safety in the industry.

Statistics

Views

Total Views
275
Views on SlideShare
275
Embed Views
0

Actions

Likes
0
Downloads
10
Comments
0

0 Embeds 0

No embeds

Accessibility

Upload Details

Uploaded via as Adobe PDF

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment

    Electrical Commissioning and Arc-Flash Safety presentation Electrical Commissioning and Arc-Flash Safety presentation Presentation Transcript

    • Electrical Commissioning and Arc Flash BUILD. CONNECT. ACHIEVE. Michael E. Luffred, ACP Eaton Energy Solutions, Inc. 1 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Learning Objectives • General overview of OSHA regulations and the relationship of it to consensus standard NFPA 70E. • Understand the cause and intensity of arc flash event. • Highlight safety requirements around working on energized electrical equipment. • Discuss the electrical commissioning process as it relates to arc flash. • Learn measures that can be taken as a commissioning provider to reduce the likelihood on an arc flash event from occurring. 2 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • General Information The following words derive from various sources including the Code of Federal Regulations (USA), Title 29, Part 1910 and the NFPA Standard 70E–2012 Edition. When you see them in this slide presentation their meanings are as follows: Word “shall” “may” “must” “should” 3 Meaning Law mandate the action (OSHA) Almost always mandated, some limited exceptions (OSHA) Recommended policy, need to have very good reasons to disregard Recommended practice under normal circumstances (OSHA) NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Occupational Safety and Health Act of 1970 • AN ACT: To assure safe and healthful working conditions for working men and women; by authorizing enforcement of the standards developed under the Act; by assisting and encouraging the States in their efforts to assure safe and healthful working conditions; by providing for research, information, education, and training in the field of occupational safety and health; and for other purposes. 4 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Occupational Safety and Health Act of 1970 • SECTION 5. DUTIES: (a.k.a. The General Duties Clause) (a) Each employer -(1) shall furnish to each of his employees employment and a place of employment which are free from recognized hazards that are causing or are likely to cause death or serious physical harm to his employees; (2) shall comply with occupational safety and health standards promulgated under this Act. (b) Each employee shall comply with occupational safety and health standards and all rules, regulations, and orders issued pursuant to this Act which are applicable to his own actions and conduct. 5 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Federal Regulations, Standards and Codes • OSHA is the agency responsible for enforcing workplace safety. • NFPA publishes consensus standards and has no authority to police or enforce compliance. • Governmental agencies do, however, reference various NFPA documents or incorporate their language into codes and regulations. 6 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Definitions: Qualified Employee and Competent Person (OSHA) A Qualified Employee must be trained and competent to: •Distinguish live parts from other parts of equipment. •Determine the nominal voltage of live parts. •Know the minimum approach distances to live parts. •Know what precautions to take to work safely. •Know how to carry out lockout/tagout procedures. •Know how to manage and maintain a safe work area. •Know how to use protective grounds. 7 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Definitions: Qualified Employee and Competent Person (OSHA) - continued A Qualified Employee must be trained and competent to: •Know how to use personal protective equipment (PPE). •Know how to use insulating and shielding materials. •Know how to use insulated tools. Reference: OSHA 1910.269(a)(2)(ii) & 1910.332(b)(3) 8 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Definitions: Qualified Employee and Competent Person (OSHA) - continued A Qualified Person Must • Be certified by his employer before working on or near energized equipment [1910.269.(a)(2)(vii)] • Have his or her qualifications reviewed annually [1910.269(a)(2)(iii)] 9 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Qualified Person as defined by NFPA 70E • Definition: Qualified Person - One who has skills and knowledge related to the construction and operation of the electrical equipment and installations and has received safety training to recognize and avoid the hazards involved. [Article 100] • A person can be considered qualified with respect to certain equipment and methods but still be unqualified for others [Article 110.6(D)(1)(a)] 10 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Qualified Person as defined by NFPA 70E • [Such persons must additionally be trained in] the decision-making process necessary to determine the degree and extent of the hazard and the personal protective equipment and job planning necessary to perform the task safely. [Article110.6(D)(1)(b)(4)] • An employee who is undergoing on-the-job training and who, in the course of such training, has demonstrated an ability to perform duties safely at his or her level of training and who is under the direct supervision of a qualified person shall be considered to be a qualified person for the performance of those duties [Article 110.6(D)(1)(c)] 11 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Training: OSHA Standard Number 1910.332 (a) Scope. . . employees who face a risk of electric shock that is not reduced to a safe level by the electrical installation requirements . . . 12 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Training: OSHA Standard Number 1910.332 Note: Employees in occupations listed in Table S4 face such a risk and are required to be trained. Other employees who also may reasonably be expected to face a comparable risk of injury due to electric shock or other electrical hazards must also be trained. TABLE S-4. -- Typical Occupational Categories of Employees Facing a Higher Than Normal Risk of Electrical Accident Occupation: Blue collar supervisors(*), Electrical and electronic engineers(*), Electrical and electronic equipment assemblers(*), Electrical and electronic technicians(*), Electricians, Industrial machine operators(*), Material handling equipment operators(*), Mechanics and repairers(*), Painters(*), Riggers and roustabouts(*), Stationary engineers(*), Welders Footnote(*) Workers in these groups do not need to be trained if their work or the work of those they supervise does not bring them or the employees they supervise close enough to exposed parts of electric circuits operating at 50 volts or more to ground for a hazard to exist. 13 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Training: OSHA Standard Number 1910.332 (b) Content of training. (1) Practices addressed in . . . standard. . . 1910.331 through 1910.335 that pertain to their respective job assignments. (2) . . . persons . . . who are not qualified shall also be trained in and familiar with any electrically related safety practices not specifically addressed by 1910.331 through 1910.335 but which are necessary for their safety. (3) Qualified persons . . . shall, at a minimum, be trained in and familiar with the following: (i) The skills and techniques necessary to distinguish exposed live parts from other. . . (ii) The skills and techniques necessary to determine the nominal voltage of exposed live parts (iii) The clearance distances . . . and the corresponding voltages to which the qualified person will be exposed. 14 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Training: OSHA Standard Number 1910.332 (c) Type of training. The training required by this section shall be of the classroom or onthe-job type. The degree of training provided shall be determined by the risk to the employee. 15 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Training Requirements: NFPA 70E Article 110.2(D)(1) adds to the definition by listing the training requirements for a qualified person. • Person receiving training on the job and under direct supervision has demonstrated safe work practices to his supervisor can be considered qualified. • Implication: formal documentation of the person's qualifications are not needed under this circumstance. • Another implication: formal documentation would be needed before same person could perform tasks without direct supervision. 16 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Re-training Requirements: NFPA70E Article 110.2(D)(3) says that retraining shall be performed at intervals not to exceed three years. 17 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Your Employer's Electrical Safety Program Your employer is required to develop, implement and document a program of electrical safety. The program must be tailored to the kinds of hazards you might encounter. 18 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Electrical Commissioning and Arc Flash 19 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Introduction • So what exactly is arc flash? • And why is knowing about it and it’s prevention important to electrical commissioning? 20 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • What is Electrical Commissioning? • Commissioning Process for Buildings and Systems ANSI/ASHRAE/IES Standard 202-2013 – Commissioning Process: A qualityfocused process for enhancing the delivery of a project. The process focuses upon verifying and documenting that all of the commissioned systems and assemblies are planned, designed, installed, tested, operated, and maintained to meet the Owner's Project Requirements. 21 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • What is Electrical Commissioning? • The Commissioning Process for Buildings and Systems ASHRAE Guideline 0-2005 – “The Commissioning Process is a quality-oriented process for achieving, verifying, and documenting that the performance of facilities, systems, and assemblies meets defined objectives and criteria.” 22 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • The Process of Commissioning • Works to ensure that the finished facility meets the OPR. • Integrated into every phase of the project: – – – – Project Initiation /Pre-Design Design Construction Occupancy / Operations • Commissioning is NOT just testing at the end of the job! 23 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Commissioning Phases 24 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • What is an Arc Flash? 25 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • What is an Arc Flash? NPFA 70-E 2012: “when an electric current passes through air between ungrounded conductors or between ungrounded conductors and grounded conductors.” 26 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Arc Flash Event • A dangerous release of energy created by an electrical fault • Release will contain: – – – – – – 27 Thermal energy (heat) Toxic fumes Blinding light Acoustical energy Pressure waves Debris NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Arc Flash Event Injuries that can result from an arc flash: • Burns • Respiratory system damage • Hearing damage • Skin penetration from flying debris • Eye and face injuries • Possibly death 28 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Arc Flash - ImportantTemperatures • • • • • • • 29 Skin temperature for curable burn Skin temperature causing cell death Ignition of clothing Burning clothing Metal droplets from arcing Surface of sun Arc terminals 176°F 205°F 752°-1472°F 1472°F 1832°F 9000°F 35,000°F NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Arc Flash Event • Rapid heating & expansion of air and materials surrounding area of arc. – 67,000x expansion for copper that vaporize • Fatal burns >10 feet • Majority of hospital admissions are arc flash burns, not shock • 30,000 arcs, 7,000 burn injuries per year • Over 2,000 people admitted to burn centers yearly with severe arc flash burns 30 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Arc Flash Intensity • Variables that affect the size and energy of an electric arc flash are: – – – – – – – 31 Amperage Voltage Arc gap Closure time Distance away from arc 3 phase vs. single – phase Confined space NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Some Statistics • 4,383 workers were killed on the job in 2012 [BLS revised 2012 workplace facility data] • 775 worker fatalities were in construction • 66 (9%) of these deaths were attributed to electrocution • Electrocution is the third leading cause of workplace death • 3 of the 10 top most frequently cited OSHA standards violated are electrical based – Control of hazardous energy (lockout/tagout), general industry (29 CFR 1910.147) – Electrical systems design, general requirements, general industry (29 CFR 1910.303) – Electrical, wiring methods, components and equipment, general industry (29 CFR 1910.305) https://www.osha.gov/oshstats/commonstats.html 32 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Some Statistics • More than 30,000 non-fatal shock accidents occur each year. • In the construction industry, non-fatal electric shocks injuries occur at a rate of 0.6 cases per / 10,000 workers annually – highest in any industry • Estimated 5 to 10 arc explosions occur in electrical equipment every day in the U.S. • Average cost per incident estimated at over $1,000,000 • The average cost of medical treatment for survivors of arc flash is $1.5 million. Total costs have been estimated at $12 – 15 million per incident. 33 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Arc Flash at ExxonMobil 34 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • So what’s the point? • Working on and around electrical equipment is hazardous work. • As a commissioning service provider we must exercise and be a proponent of safe electrical work practices while commissioning. • Help the project team mitigate arc flash events. 35 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Pre-Design Phase Actions • Recognize that project requirements has arc flash potential. • Be prepared to help the owner capture their arc flash requirements and associated safe work practices in the OPR. 36 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Design Phase Actions • Specify Cx procedures that indicate a reasonable level of effort to be safe • HVAC & filtering of equipment should be appropriate for the installations • Design systems so that open & inspections of critical systems can be performed without disruptions to the mission. • Recommend Arc Flash reducing equipment and procedures. 37 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Arc Flash Reducing Equipment • Metal-clad switchgear 38 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Arc Flash Reducing Equipment • Arc-Resistant switchgear Arc Flaps Vent VT Compartment Control Compartment 39 Manual Close-Open Plates NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • EEMAC G14-1 Table 1: Locations, Causes and Examples of Measures to Decrease the Probability of Internal Faults or Reduce the Risk. Locations where internal faults are more likely to occur Possible cause of internal faults Examples of measures Inadequate design Selection of adequate dimensions Faulty installation Avoidance of crossed cable connections. Checking of workmanship on site. Cable Termination Compartments Failure of solid or liquid insulation (defective or missing) Check of workmanship and/or dielectric test on site. Regular checking of liquid levels. Mal-Operation Interlocks. Delays re-opening. Independent manual operation. Making capacity for switches and grounding switches. Instructions to personnel. Corrosion Use of corrosion inhibiting coatings and/or greases. Encapsulation where possible. Faulty Assembly Checking of workmanship by suitable means. Instrument Transformers Ferroresonance Avoidance of these electrical influences by suitable design of the circuit. Circuit Breakers Insufficient maintenance Regular programmed maintenance. Instructions to personnel. Error by personnel Limitation of access by compartmentation. Insulation embedded live parts. Instructions to personnel. Aging under electric stresses Partial discharge routine tests Pollution, moisture, dust, vermin, etc. Measures to ensure that the ingress specified service conditions are achieved. Disconnection Switches Grounding Switches Bolted Connections and Contacts All Locations 40 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Arc Flash Reducing Equipment • Arc flash reducing maintenance switches 41 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Arc Flash Reducing Equipment • Zone-selective interlocking 42 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Arc Flash Reducing Equipment • Add current-limiting reactors 43 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Construction Phase Actions • Recognize the impacts of construction changes • Insist on equipment installations to be clean and/or maintained once energized • Temporary air filtration • Good housekeeping • Keep boundaries clear of stored materials • Guarding of energized parts OSHA 1910.335 (a) – (b) • Cx team practice safe work around energized equipment. 44 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Safe Work Practices • Close and latch compartment doors before operating a switch. • Switch remotely . • Use a remote racking device. 45 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Safe Work Practices • While switching, stand to the side and away as much as possible from the prospectus path of the arc flash. Bad practice – Exposed Back of Neck 46 Good practice – Entire Body Protected NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Safe Work Practices • Consider new methods to perform familiar tasks. – viewing windows or viewing ports for infrared scanning. 47 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Safe Work Practices • Avoid leaning on switchgear or touching metallic surfaces during switching procedures. • Use the proper tools for the project. • De-Energize equipment when feasible. • Don’t work alone. • Remove jewelry. • Secure your phone. • Use the one-hand method. 48 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Construction Phase Actions • Owner training should address issues of continuous inspection and cleaning as appropriate • Obtain copy of computer model of system that was used to create short circuit study & coordination study • Instruments are appropriate for equipment use – Donnie’s Accident story – http://www.donniesaccident.com/full-story • Have appropriate PPE available 49 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Construction Phase Actions • Follow lock out and tag out procedures • Utilize data loggers / remote sensing equipment when possible • Be cognizant of back feed. – Cooling tower fans – Dual feed systems • Cleanliness – Tripping hazards – Conductive materials falling into limit approach boundary • Have facilities electrical representatives participate in system functional testing. 50 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Construction Phase Actions • Labeling is completed as soon as possible. • Don’t assume anything – – – – – – – – – 51 Neutral isn’t energized Unproven circuit breaker will trip Overload setting is low enough Cable terminations are tight Housekeeping has been kept up Labeling is correct Lock-out /tag-out is the same as yesterday Off is not hot Recent installed relays / fuses are calibrated / good NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Occupancy & Operations Phase Actions • Ensure that more than one person is completely trained on the operation of the equipment and can bring it back on line. • Written procedures how to restore power. • Short circuit, coordination and arc flash study up to date • Open and inspect critical equipment • Ensure EMCS documentation and programs are obtained from vendors and archived. • Maintain equipment – Lubricant deterioration – Cleanliness 52 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Arc Flash at New Campus East • Evening of May 1, 2010 • Prep testing for upcoming Integrated System Test • Flashover in the rear of 34.5 kV Switchgear SS-2 in section 12 (tie breaker that connects to SS-1 cell) • Phase A to ground • Evidence of arcing in another section • Fault of 23 cycles or .38 seconds 53 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Pictures of SS2 Gear (Orientation 1 of 3) SS2 Gear comprised of 14 Cubicles Front Side (Contains Breakers) Back Side (Contains: Cubicle Bus Bars, Bushings/Boots and Cables) 54 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • NCE Overall Campus Single Line Diagram (2 of 3) SS1 SS2 SS1/SS2 Switchgear 55 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • SS1/SS2 Switch Gear (3 of 3) SS2 Gear comprised of 14 Cubicles SS1 SS2 12 13 14 1 2 3 4 5 6 7 8 9 10 11 Issue with Hipot Testing on 6MAY10 56 Location of Fault in Cubicle 12 on 1MAY10 at ~2200 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Pictures SS2/SS1 Comparison Tie Feeder to SS1 (where fault occurred-cubicle 12 in SS2 Gear) Back Side (Bus Bars and Bushings) Front Side (where ~900lb Breaker goes) Tie Feeder to SS2 (SS1 Gear) 57 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Damage to Components in SS2 Cubicle 12 Cubicle 12 Bus Bars that have to be replaced (Back Side) Oxidation on Ground bar In Cubicle 12 (Back Side) 58 ~900lb SS2 Cubicle 12 Breaker (Front Side) NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Potential Cause of SS2 Failure • • • • • • 59 The cell in SS2 that failed on 1MAY10 was found to be “heavily contaminated” with dust (Cx Team to investigate type of dust) Bushing boot was found to have the beginning stages of “tracking” “the formation of partially conductive paths across the surface of an electrical insulator that degrade or destroy, its insulating capabilities” Since contamination was found in SS2 it is assumed it also exists in SS1; therefore SS1 must also be inspected for potential contamination In order to remove contamination from SS2 all 84 boots (6 boots/cubicle, 14 cubicles) have to be replaced. Cx Team and Electrical Experts are still determining if any modifications need to be done to the gear or conditioning of electrical spaces to prevent “contamination” of the gear from occurring again. NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Removal of Boots and “Tracking” on Boots Examples of Tracking Removal of all 84 boots in SS2 (6 boots/cubicle, 14 cubicles) 60 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Summary • We can help our clients reduce their risks for arc flash. • Cx providers have the same responsibilities as electricians to perform safe work practices. • Be a proponent of Arc Flash electrical safety… the threat is real! 61 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • References • • • • • 62 Code of Federal Regulations (USA), Title 29, Part 1910: Occupational Safety and Health Standards (OSHA Standards – General Industry) Code of Federal Regulations (USA), Title 29, Part 1926: Safety and Health Regulations for Construction (OSHA Standards - Construction) NFPA Standard 70E-2012: Standard for Electrical Safety in the Workplace IEEE 1584-2002: Guide for Performing Arc Flash Hazard Calculations Eaton White Paper: Innovative Techniques for Mitigating Arc Flash Exposure (eaton.com/arcflash) NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Questions? 63 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • Final Exam Which panel will cause an arc flash event that will impact your project? 64 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013
    • 0 NATIONAL CAPITAL CHAPTER EVENT AT EATON’S PSEC | 2013