Philippine electrical code


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Philippine electrical code

  1. 1. Chapter 1. General ARTICLE 1.0 — INTRODUCTION1.0.1.1 Purpose. (a) Practical Safeguarding. The purpose of this Code is thepractical safeguarding of persons and property from hazards arisingfrom the use of electricity. (b) Adequacy. This Code contains provisions that are consideredminimum requirements necessary for safety. Compliance therewithand proper maintenance will result in an installation that is essentiallyfree from hazard but not necessarily efficient, convenient, or adequatefor good service or future expansion of electrical use. FPN No. 1: Hazards often occur because of overloading of wiring systems by methods or usage not in conformity with this Code. This occurs because initial wiring did not provide for increases in the use of electricity. An initial adequate installation and reasonable provisions for system changes will provide for future increases in the use of electricity. FPN No 2: It is highly recommended that a licensed electrical practitioner be consulted for any electrical requirements, including changes. Failure to do so may result in fire, serious injury, or death. FPN No. 3: Fire hazard, electrocution, serious injury or even death may also occur with lack or improper maintenance of wiring system. Wiring system is recommended to be inspected and tested by a licensed electrical practitioner at least once a year for wiring system of more than three (3) years in installation. (c) Intention. This Code is intended for the exclusive use oflicensed electrical practitioners (PEE, REE, and RME). This Code isnot intended as a design specification nor an instruction manual for anon-licensed electrical practitioner, unless under the supervision of alicensed electrical practitioner. (d) Relation to Other International Standards. The requirementsin this Code address the fundamental principles of protection for safety
  2. 2. contained in Section 131 of International Electrotechnical Commission Authority.Standard 60364-1, Electrical Installations of Buildings. (a) This Code has been approved and adopted by the Board of FPN: IEC 60364-1, Section 131. Contains fundamental principles of protection for Electrical Engineering, Professional Regulation Commission. safety that encompass protection against thermal effects, protection against overcurrent, protection against fault currents, and protection against overvoltage. All of these potential hazards are addressed by the requirements in this Code. (b) By virtue of authority vested in the Board under RA 7920, it hereby direct strict adherence to the provisions of this Code. Scope. (c) Where deviations from these provisions are necessary, such (a) Covered. This Code covers the installation of electrical deviations shall not be made, except with written permission from thisconductors, equipment, and raceways; signaling and communications government bodies exercising legal jurisdiction applicable only to theconductors, equipment, and raceways; and optical fiber cables and particular job for which such permission was granted.raceways installed within or on, to or from: Enforcement. (1) Public and private buildings, including but not limited toresidential, commercial, industrial, institutional, cultural, agricultural, (a) This Code is intended for mandatory application by governmentagro-industrial, planned unit development and all other bodies exercising legal jurisdiction over electrical installations.buildings/premises that may require practical safeguarding of personsand property from the hazards arising from the use of electricity. (b) These government bodies, only through a licensed electrical (2) Electric generating plants practitioner, shall have the responsibility of implementing the (3) Industrial plants provisions of this Code in deciding on the approval of equipment and (4) Transformer stations materials and for granting the special permission contemplated in this (5) Permanent and temporary substations, etc. Code, where it is assured that equivalent objectives can be achieved by (6) Airfields establishing and maintaining effective safety. (7) Railways switchyards (8) Yards, carnival, parks, parking and other lots (c) The authority having jurisdiction may waive specific (9) Quarries and mines requirements in this Code or permit alternate methods where it is (10) Watercraft assured that equivalent objectives can be achieved by establishing and (11) Dockyards maintaining effective safety. (12) Trailers (13) Mobile homes and recreational vehicles (d) This Code may require new products, constructions, or materials (14) Offshore facilities that may not yet be available at the time this Code is adopted. In such event, the authority having jurisdiction may permit the use of the (b) Not Covered. This Code does not cover the following: products, constructions, or materials that comply with the most recent previous edition of this Code adopted by the jurisdiction. (1) Installations in railway rolling stock, aircraft, or automotivevehicles FPN: Application of electrical products and equipment for additional installation or replacement is suggested to be consulted with a licensed electrical practitioner (2) Installations of railways for generation, transformation, prior to installation for safety.transmission, or distribution of power used exclusively for operationof rolling stock
  3. 3. Mandatory Rules, Permissive Rules, and ExplanatoryMaterial. FPN No. 1: See requirements in Section FPN No. 2: Listed is defined in Article 1.0 (a) Mandatory Rules. Mandatory rules of this Code are those thatidentify actions that are specifically required or prohibited and are FPN No. 3: Appendix A contains an informative list of product safety standards for electrical equipment.characterized by the use of the terms shall or shall not. FPN No. 4: Application of electrical equipment and devices shall always be consulted with a licensed electrical practitioner. (b) Permissive Rules. Permissive rules of this Code are those thatidentify actions that are allowed but not required, are normally used to Wiring Planning.describe options or alternative methods, and are characterized by theuse of the terms shall be permitted or shall not be required. (a) Future Expansion and Convenience. Plans and specifications that provide ample space in raceways, spare raceways, and additional (c) Explanatory Material. Explanatory material, such as references spaces allow for future increases in electric power and communicationto other standards, references to related sections of this Code, or circuits. Distribution centers located in readily accessible locationsinformation related to a Code rule, is included in this Code in the form provide convenience and safety of operation.of fine print notes (FPN). Fine print notes are informational only andare not enforceable as requirements of this Code. (b) Number of Circuits in Enclosures. It is elsewhere provided in this Code that the number of wires and circuits confined in a single1.0.1.6 Interpretation. In case of controversy, the recommendation of enclosure be varyingly restricted. Limiting the number of circuits in athe Code Committee and concurrence of the Board of Electrical single enclosure will minimizes the effects from a short circuit orEngineering shall be the final interpretation of any portion of the ground fault in one circuit.Philippine Electrical Code Part 1. Metric Units of Measurement. For the purpose of this Code, Examination of Equipment for Safety. For specific items of metric units of measurement are in accordance with the modernizedequipment and materials referred to in this Code, examinations for metric system known as the International System of Units (SI).safety made under standard conditions will provide a basis forapproval where the record is made generally available throughpromulgation by organizations properly equipped and qualified for ARTICLE 1.1 — DEFINITIONSexperimental testing, inspections of the run of goods at factories, andservice-value determination through field inspections. This avoids the Scope. This article contains only those definitions essential tonecessity for repetition of examinations by different examiners, the proper application of this Code. It is not intended to includefrequently with inadequate facilities for such work, and the confusion commonly defined general terms or commonly defined technical termsthat would result from conflicting reports as to the suitability of from related codes and standards. In general, only those terms that aredevices and materials examined for a given purpose. used in two or more articles are defined in Article 100. OtherIt is the intent of this Code that factory-installed internal wiring or the definitions are included in the article in which they are used but mayconstruction of equipment need not be inspected at the time of be referenced in Article 1.0.installation of the equipment, except to detect alterations or damage, if Part 1.1.1 of this article contains definitions intended to applythe equipment has been listed by a qualified electrical testing wherever the terms are used throughout this Code. Part 1.1.2 containslaboratory that is recognized as having the facilities described in the definitions applicable only to the parts of articles specifically coveringpreceding paragraph and that requires suitability for installation in installations and equipment operating at over 600 volts, nominal.accordance with this Code.
  4. 4. 1.1.1 General FPN: The phrase “authority having jurisdiction” is used in NFPA documents in a broad manner, since jurisdictions and approval agencies vary, as do their responsibilities. Where public safety is primary, the AHJ may be a federal, state, Accessible (as applied to equipment). Admitting close approach; local, or other regional department or individual such as a fire chief; fire marshal;not guarded by locked doors, elevation, or other effective means. chief of a fire prevention bureau, labor department, or health department; building official; electrical inspector; or others having statutory authority. For insurance purposes, an insurance inspection department, rating bureau, or other insurance Accessible (as applied to wiring methods). Capable of being company representative may be the AHJ. In many circumstances, the property owner or his or her designated agent assumes the role of the AHJ; at governmentremoved or exposed without damaging the building structure or finish installations, the commanding officer or departmental official may be the AHJ.or not permanently closed in by the structure or finish of the building. Automatic. Self-acting, operating by its own mechanism when Accessible, Readily (Readily Accessible). Capable of being actuated by some impersonal influence, as, for example, a change inreached quickly for operation, renewal, or inspections without current, pressure, temperature, or mechanical configuration.requiring those to whom ready access is requisite to climb over orremove obstacles or to resort to portable ladders, and so forth. Bathroom. An area including a basin with one or more of the following: a toilet, a tub, or a shower. Ampacity. The current, in amperes, that a conductor can carrycontinuously under the conditions of use without exceeding its Bonding (Bonded). The permanent joining of metallic parts to formtemperature rating. an electrically conductive path that ensures electrical continuity and the capacity to conduct safely any current likely to be imposed. Appliance. Utilization equipment, generally other than industrial,that is normally built in standardized sizes or types and is installed or Bonding Jumper. A reliable conductor to ensure the requiredconnected as a unit to perform one or more functions such as clothes electrical conductivity between metal parts required to be electricallywashing, air conditioning, food mixing, deep frying, and so forth. connected. Approved. Acceptable to the authority having jurisdiction. Bonding Jumper, Equipment. The connection between two or more portions of the equipment grounding conductor. Askarel. A generic term for a group of nonflammable syntheticchlorinated hydrocarbons used as electrical insulating media. Askarels Bonding Jumper, Main. The connection between the groundedof various compositional types are used. Under arcing conditions, the circuit conductor and the equipment grounding conductor at thegases produced, while consisting predominantly of noncombustible service.hydrogen chloride, can include varying amounts of combustible gases,depending on the askarel type. Bonding Jumper, System. The connection between the grounded circuit conductor and the equipment grounding conductor at a Attachment Plug (Plug Cap) (Plug). A device that, by insertion in separately derived system.a receptacle, establishes a connection between the conductors of theattached flexible cord and the conductors connected permanently to Branch Circuit. The circuit conductors between the finalthe receptacle. overcurrent device protecting the circuit and the outlet(s). Authority Having Jurisdiction (AHJ). The organization, office, or Branch Circuit, Appliance. A branch circuit that supplies energy toindividual responsible for approving equipment, materials, an one or more outlets to which appliances are to be connected and thatinstallation, or a procedure.
  5. 5. has no permanently connected luminaires (lighting fixtures) that are action of the circuit breaker, which delay decreases as the magnitudenot a part of an appliance. of the current increases. Branch Circuit, General-Purpose. A branch circuit that supplies Nonadjustable (as applied to circuit breakers). A qualifying termtwo or more receptacles or outlets for lighting and appliances. indicating that the circuit breaker does not have any adjustment to alter the value of current at which it will trip or the time required for its Branch Circuit, Individual. A branch circuit that supplies only one operation.utilization equipment. Setting (of circuit breakers). The value of current, time, or both, at Branch Circuit, Multiwire. A branch circuit that consists of two or which an adjustable circuit breaker is set to trip.more ungrounded conductors that have a voltage between them, and agrounded conductor that has equal voltage between it and each Concealed. Rendered inaccessible by the structure or finish of theungrounded conductor of the circuit and that is connected to the building. Wires in concealed raceways are considered concealed, evenneutral or grounded conductor of the system. though they may become accessible by withdrawing them. Building. A structure that stands alone or that is cut off from Conductor, Bare. A conductor having no covering or electricaladjoining structures by fire walls with all openings therein protected insulation approved fire doors. Conductor, Covered. A conductor encased within material of Cabinet. An enclosure that is designed for either surface mounting composition or thickness that is not recognized by this Code asor flush mounting and is provided with a frame, mat, or trim in which electrical insulation.a swinging door or doors are or can be hung. Conductor, Insulated. A conductor encased within material of Circuit Breaker. A device designed to open and close a circuit by composition and thickness that is recognized by this Code as electricalnonautomatic means and to open the circuit automatically on a insulation.predetermined overcurrent without damage to itself when properlyapplied within its rating. Conduit Body. A separate portion of a conduit or tubing system that provides access through a removable cover(s) to the interior of the FPN: The automatic opening means can be integral, direct acting with the circuit system at a junction of two or more sections of the system or at a breaker, or remote from the circuit breaker. terminal point of the system. Boxes such as FS and FD or larger cast or sheet metal boxes are not Adjustable (as applied to circuit breakers). A qualifying term classified as conduit bodies.indicating that the circuit breaker can be set to trip at various values ofcurrent, time, or both, within a predetermined range. Connector, Pressure (Solderless). A device that establishes a connection between two or more conductors or between one or more Instantaneous Trip (as applied to circuit breakers). A qualifying conductors and a terminal by means of mechanical pressure andterm indicating that no delay is purposely introduced in the tripping without the use of solder.action of the circuit breaker. Continuous Load. A load where the maximum current is expected Inverse Time (as applied to circuit breakers). A qualifying term to continue for 3 hours or more.indicating that there is purposely introduced a delay in the tripping
  6. 6. Controller. A device or group of devices that serves to govern, in Duty, Continuous. Operation at a substantially constant load for ansome predetermined manner, the electric power delivered to the indefinitely long time.apparatus to which it is connected. Duty, Intermittent. Operation for alternate intervals of (1) load and Cooking Unit, Counter-Mounted. A cooking appliance designed no load; or (2) load and rest; or (3) load, no load, and rest.for mounting in or on a counter and consisting of one or more heatingelements, internal wiring, and built-in or mountable controls. Duty, Periodic. Intermittent operation in which the load conditions are regularly recurrent. Coordination (Selective). Localization of an overcurrent conditionto restrict outages to the circuit or equipment affected, accomplished Duty, Short-Time. Operation at a substantially constant load for aby the choice of overcurrent protective devices and their ratings or short and definite, specified time.settings. Duty, Varying. Operation at loads, and for intervals of time, both of Copper-Clad Aluminum Conductors. Conductors drawn from a which may be subject to wide variation.copper-clad aluminum rod with the copper metallurgically bonded toan aluminum core. The copper forms a minimum of 10 percent of the Dwelling Unit. A single unit, providing complete and independentcross-sectional area of a solid conductor or each strand of a stranded living facilities for one or more persons, including permanentconductor. provisions for living, sleeping, cooking, and sanitation. Cutout Box. An enclosure designed for surface mounting that has Dwelling, One-Family. A building that consists solely of oneswinging doors or covers secured directly to and telescoping with the dwelling unit.walls of the box proper. Dwelling, Two-Family. A building that consists solely of two Dead Front. Without live parts exposed to a person on the operating dwelling units.side of the equipment. Dwelling, Multifamily. A building that contains three or more Demand Factor. The ratio of the maximum demand of a system, or dwelling units.part of a system, to the total connected load of a system or the part ofthe system under consideration. Electric Sign. A fixed, stationary, or portable self-contained, electrically illuminated utilization equipment with words or symbols Device. A unit of an electrical system that is intended to carry or designed to convey information or attract attention.control but not utilize electric energy. Electrical Practitioner, Licensed. One who has undergone training Disconnecting Means. A device, or group of devices, or other in electrical engineering and has complied with the requirements ofmeans by which the conductors of a circuit can be disconnected from Republic Act 7920 or otherwise known as the New Electricaltheir source of supply. Engineering Law. Dusttight. Constructed so that dust will not enter the enclosing case Electrical Practitioner, Non-Licensed. An electrical practitionerunder specified test conditions. that has not complied with the requirements of RA 7920 or a qualified person with relevant education and experience to enable him or her to perceive risks and to avoid hazards which electricity can create.
  7. 7. Festoon Lighting. A string of outdoor lights that is suspended Enclosed. Surrounded by a case, housing, fence, or wall(s) that between two points.prevents persons from accidentally contacting energized parts. Fitting. An accessory such as a locknut, bushing, or other part of a Enclosure. The case or housing of apparatus, or the fence or walls wiring system that is intended primarily to perform a mechanicalsurrounding an installation to prevent personnel from accidentally rather than an electrical function.contacting energized parts or to protect the equipment from physicaldamage. Garage. A building or portion of a building in which one or more self-propelled vehicles can be kept for use, sale, storage, rental, repair, FPN: See Table for examples of enclosure types. exhibition, or demonstration purposes. Energized. Electrically connected to a source of voltage. FPN: For commercial garages, repair and storage, see Article 5.11. Equipment. A general term including material, fittings, devices, Ground. A conducting connection, whether intentional orappliances, luminaires (fixtures), apparatus, and the like used as a part accidental, between an electrical circuit or equipment and the earth orof, or in connection with, an electrical installation. to some conducting body that serves in place of the earth. Explosionproof Apparatus. Apparatus enclosed in a case that is Grounded. Connected to earth or to some conducting body thatcapable of withstanding an explosion of a specified gas or vapor that serves in place of the earth.may occur within it and of preventing the ignition of a specified gas orvapor surrounding the enclosure by sparks, flashes, or explosion of the Grounded, Effectively. Intentionally connected to earth through agas or vapor within, and that operates at such an external temperature ground connection or connections of sufficiently low impedance andthat a surrounding flammable atmosphere will not be ignited thereby. having sufficient current-carrying capacity to prevent the buildup of voltages that may result in undue hazards to connected equipment or FPN: For further information, see ANSI/UL 1203-1999, Explosion-Proof and Dust- to persons. Ignition-Proof Electrical Equipment for Use in Hazardous (Classified) Locations. Grounded, Solidly. Connected to ground without inserting any Exposed (as applied to live parts). Capable of being inadvertently resistor or impedance device.touched or approached nearer than a safe distance by a person. It isapplied to parts that are not suitably guarded, isolated, or insulated. Grounded Conductor. A system or circuit conductor that is intentionally grounded. Exposed (as applied to wiring methods). On or attached to thesurface or behind panels designed to allow access. Ground-Fault Circuit Interrupter (GFCI). A device intended for the protection of personnel that functions to de-energize a circuit or Externally Operable. Capable of being operated without exposing portion thereof within an established period of time when a current tothe operator to contact with live parts. ground exceeds the values established for a Class A device. Feeder. All circuit conductors between the service equipment, the FPN: Class A ground-fault circuit interrupters trip when the current to ground has asource of a separately derived system, or other power supply source value in the range of 4 mA to 6 mA. For further information, see UL 943, Standardand the final branch-circuit overcurrent device. for Ground-Fault Circuit Interrupters.
  8. 8. Ground-Fault Protection of Equipment. A system intended to sized to allow personnel to reach into, but not enter, for the purpose ofprovide protection of equipment from damaging line-to-ground fault installing, operating, or maintaining equipment or wiring or both.currents by operating to cause a disconnecting means to open allungrounded conductors of the faulted circuit. This protection is Hoistway. Any shaftway, hatchway, well hole, or other verticalprovided at current levels less than those required to protect opening or space in which an elevator or dumbwaiter is designed toconductors from damage through the operation of a supply circuit operate.overcurrent device. Identified (as applied to equipment). Recognizable as suitable for Grounding Conductor. A conductor used to connect equipment or the specific purpose, function, use, environment, application, and sothe grounded circuit of a wiring system to a grounding electrode or forth, where described in a particular Code requirement.electrodes. FPN: Some examples of ways to determine suitability of equipment for a specific purpose, environment, or application include investigations by a qualified testing Grounding Conductor, Equipment. The conductor used to laboratory (listing and labeling), an inspection agency, or other organizationsconnect the non–current-carrying metal parts of equipment, raceways, concerned with product evaluation.and other enclosures to the system grounded conductor, the groundingelectrode conductor, or both, at the service equipment or at the source In Sight From (Within Sight From, Within Sight). Where thisof a separately derived system. Code specifies that one equipment shall be “in sight from,” “within sight from,” or “within sight,” and so forth, of another equipment, the Grounding Electrode. A device that establishes an electrical specified equipment is to be visible and not more than 15 m distantconnection to the earth. from the other. Grounding Electrode Conductor. The conductor used to connect Interrupting Rating. The highest current at rated voltage that athe grounding electrode(s) to the equipment grounding conductor, to device is intended to interrupt under standard test conditions.the grounded conductor, or to both, at the service, at each building orstructure where supplied by a feeder(s) or branch circuit(s), or at the FPN: Equipment intended to interrupt current at other than fault levels may have its interrupting rating implied in other ratings, such as horsepower or locked rotorsource of a separately derived system. current. Guarded. Covered, shielded, fenced, enclosed, or otherwise Isolated (as applied to location). Not readily accessible to personsprotected by means of suitable covers, casings, barriers, rails, screens, unless special means for access are used.mats, or platforms to remove the likelihood of approach or contact bypersons or objects to a point of danger. Labeled. Equipment or materials to which has been attached a label, symbol, or other identifying mark of an organization that is acceptable Guest Room. An accommodation combining living, sleeping, to the authority having jurisdiction and concerned with productsanitary, and storage facilities within a compartment. evaluation, that maintains periodic inspection of production of labeled equipment or materials, and by whose labeling the manufacturer Guest Suite. An accommodation with two or more contiguous indicates compliance with appropriate standards or performance in arooms comprising a compartment, with or without doors between such specified manner.rooms, that provides living, sleeping, sanitary, and storage facilities. Lighting Outlet. An outlet intended for the direct connection of a Handhole Enclosure. An enclosure identified for use in lampholder, a luminaire (lighting fixture), or a pendant cordunderground systems, provided with an open or closed bottom, and terminating in a lampholder.
  9. 9. ventilating openings and inspection windows) containing primary Listed. Equipment, materials, or services included in a list published power circuit switching, interrupting devices, or both, with buses andby an organization that is acceptable to the authority having connections. The assembly may include control and auxiliary devices.jurisdiction and concerned with evaluation of products or services, that Access to the interior of the enclosure is provided by doors, removablemaintains periodic inspection of production of listed equipment or covers, or both.materials or periodic evaluation of services, and whose listing statesthat the equipment, material, or services either meets appropriate Motor Control Center. An assembly of one or more encloseddesignated standards or has been tested and found suitable for a sections having a common power bus and principally containing motorspecified purpose. control units. FPN: The means for identifying listed equipment may vary for each organization Multioutlet Assembly. A type of surface, flush, or freestanding concerned with product evaluation, some of which do not recognize equipment as listed unless it is also labeled. Use of the system employed by the listing raceway designed to hold conductors and receptacles, assembled in the organization allows the authority having jurisdiction to identify a listed product. field or at the factory. Live Parts. Conductor or conductive part intended to be energized Nonautomatic. Action requiring personal intervention for itsin normal use. control. As applied to an electric controller, nonautomatic control does not necessarily imply a manual controller, but only that personal Location, Damp. Locations protected from weather and not subject intervention is saturation with water or other liquids but subject to moderatedegrees of moisture. Examples of such locations include partially Nonlinear Load. A load where the wave shape of the steady-stateprotected locations under canopies, marquees, roofed open porches, current does not follow the wave shape of the applied voltage.and like locations, and interior locations subject to moderate degreesof moisture, such as some basements, some barns, and some cold- FPN: Electronic equipment, electronic/electric-discharge lighting, adjustable-speed drive systems, and similar equipment may be nonlinear warehouses. Outlet. A point on the wiring system at which current is taken to Location, Dry. A location not normally subject to dampness or supply utilization equipment.wetness. A location classified as dry may be temporarily subject todampness or wetness, as in the case of a building under construction. Outline Lighting. An arrangement of incandescent lamps, electric discharge lighting, or other electrically powered light sources to Location, Wet. Installations under ground or in concrete slabs or outline or call attention to certain features such as the shape of amasonry in direct contact with the earth; in locations subject to building or the decoration of a window.saturation with water or other liquids, such as vehicle washing areas;and in unprotected locations exposed to weather. Overcurrent. Any current in excess of the rated current of equipment or the ampacity of a conductor. It may result from Luminaire. A complete lighting unit consisting of a lamp or lamps overload, short circuit, or ground fault.together with the parts designed to distribute the light, to position andprotect the lamps and ballast (where applicable), and to connect the FPN: A current in excess of rating may be accommodated by certain equipmentlamps to the power supply. and conductors for a given set of conditions. Therefore, the rules for overcurrent protection are specific for particular situations. Metal-Enclosed Power Switchgear. A switchgear assemblycompletely enclosed on all sides and top with sheet metal (except for
  10. 10. Overload. Operation of equipment in excess of normal, full-load raceways, cellular metal floor raceways, surface raceways, wireways,rating, or of a conductor in excess of rated ampacity that, when it and busways.persists for a sufficient length of time, would cause damage ordangerous overheating. A fault, such as a short circuit or ground fault, Rainproof. Constructed, protected, or treated so as to prevent rainis not an overload. from interfering with the successful operation of the apparatus under specified test conditions. Panelboard. A single panel or group of panel units designed forassembly in the form of a single panel, including buses and automatic Raintight. Constructed or protected so that exposure to a beatingovercurrent devices, and equipped with or without switches for the rain will not result in the entrance of water under specified testcontrol of light, heat, or power circuits; designed to be placed in a conditions.cabinet or cutout box placed in or against a wall, partition, or othersupport; and accessible only from the front. Receptacle. A receptacle is a contact device installed at the outlet for the connection of an attachment plug. A single receptacle is a Plenum. A compartment or chamber to which one or more air ducts single contact device with no other contact device on the same yoke. Aare connected and that forms part of the air distribution system. multiple receptacle is two or more contact devices on the same yoke. Power Outlet. An enclosed assembly that may include receptacles, Receptacle Outlet. An outlet where one or more receptacles arecircuit breakers, fuseholders, fused switches, buses, and watt-hour installed.meter mounting means; intended to supply and control power tomobile homes, recreational vehicles, park trailers, or boats or to serve Remote-Control Circuit. Any electric circuit that controls anyas a means for distributing power required to operate mobile or other circuit through a relay or an equivalent device.temporarily installed equipment. Sealable Equipment. Equipment enclosed in a case or cabinet that Premises Wiring (System). That interior and exterior wiring, is provided with a means of sealing or locking so that live parts cannotincluding power, lighting, control, and signal circuit wiring together be made accessible without opening the enclosure. The equipmentwith all their associated hardware, fittings, and wiring devices, both may or may not be operable without opening the enclosure.permanently and temporarily installed, that extends from the servicepoint or source of power, such as a battery, a solar photovoltaic Separately Derived System. A premises wiring system whosesystem, or a generator, transformer, or converter windings, to the power is derived from a source of electric energy or equipment otheroutlet(s). Such wiring does not include wiring internal to appliances, than a service. Such systems have no direct electrical connection,luminaires (fixtures), motors, controllers, motor control centers, and including a solidly connected grounded circuit conductor, to supplysimilar equipment. conductors originating in another system. Raceway. An enclosed channel of metal or nonmetallic materials Service. The conductors and equipment for delivering electricdesigned expressly for holding wires, cables, or busbars, with energy from the serving utility to the wiring system of the premisesadditional functions as permitted in this Code. Raceways include, but served.are not limited to, rigid metal conduit, rigid nonmetallic conduit,intermediate metal conduit, liquidtight flexible conduit, flexible Service Cable. Service conductors made up in the form of a cable.metallic tubing, flexible metal conduit, electrical nonmetallic tubing,electrical metallic tubing, underfloor raceways, cellular concrete floor Service Conductors. The conductors from the service point to the service disconnecting means.
  11. 11. Service Drop. The overhead service conductors from the last pole Solar Photovoltaic System. The total components and subsystemsor other aerial support to and including the splices, if any, connecting that, in combination, convert solar energy into electrical energyto the service-entrance conductors at the building or other structure. suitable for connection to a utilization load. Service-Entrance Conductors, Overhead System. The service Special Permission. The written consent of the authority havingconductors between the terminals of the service equipment and a point jurisdiction.usually outside the building, clear of building walls, where joined bytap or splice to the service drop. Structure. That which is built or constructed. Service-Entrance Conductors, Underground System. The Supplementary Overcurrent Protective Device. A deviceservice conductors between the terminals of the service equipment and intended to provide limited overcurrent protection for specificthe point of connection to the service lateral. applications and utilization equipment such as luminaires (lighting fixtures) and appliances. This limited protection is in addition to the FPN: Where service equipment is located outside the building walls, there may be protection provided in the required branch circuit by the branch circuit no service-entrance conductors or they may be entirely outside the building. overcurrent protective device. Service Equipment. The necessary equipment, usually consisting Switch, Bypass Isolation. A manually operated device used inof a circuit breaker(s) or switch(es) and fuse(s) and their accessories, conjunction with a transfer switch to provide a means of directlyconnected to the load end of service conductors to a building or other connecting load conductors to a power source and of disconnecting thestructure, or an otherwise designated area, and intended to constitute transfer switch.the main control and cutoff of the supply. Switch, General-Use. A switch intended for use in general Service Lateral. The underground service conductors between the distribution and branch circuits. It is rated in amperes, and it is capablestreet main, including any risers at a pole or other structure or from of interrupting its rated current at its rated voltage.transformers, and the first point of connection to the service-entranceconductors in a terminal box or meter or other enclosure, inside or Switch, General-Use Snap. A form of general-use switchoutside the building wall. Where there is no terminal box, meter, or constructed so that it can be installed in device boxes or on box covers,other enclosure, the point of connection is considered to be the point or otherwise used in conjunction with wiring systems recognized byof entrance of the service conductors into the building. this Code. Service Point. The point of connection between the facilities of the Switch, Isolating. A switch intended for isolating an electric circuitserving utility and the premises wiring. from the source of power. It has no interrupting rating, and it is intended to be operated only after the circuit has been opened by some Show Window. Any window used or designed to be used for the other means.display of goods or advertising material, whether it is fully or partlyenclosed or entirely open at the rear and whether or not it has a Switch, Motor-Circuit. A switch rated in horsepower that isplatform raised higher than the street floor level. capable of interrupting the maximum operating overload current of a motor of the same horsepower rating as the switch at the rated voltage. Signaling Circuit. Any electric circuit that energizes signalingequipment.
  12. 12. Switch, Transfer. An automatic or nonautomatic device fortransferring one or more load conductor connections from one power Voltage, Nominal. A nominal value assigned to a circuit or systemsource to another. for the purpose of conveniently designating its voltage class (e.g., 120/240 volts, 480Y/277 volts, 600 volts). The actual voltage at which Switchboard. A large single panel, frame, or assembly of panels on a circuit operates can vary from the nominal within a range thatwhich are mounted on the face, back, or both, switches, overcurrent permits satisfactory operation of equipment.and other protective devices, buses, and usually instruments.Switchboards are generally accessible from the rear as well as from FPN: See ANSI C84.1-1995, Voltage Ratings for Electric Power Systems and Equipment (60 Hz).the front and are not intended to be installed in cabinets. Voltage to Ground. For grounded circuits, the voltage between the Thermally Protected (as applied to motors). The words given conductor and that point or conductor of the circuit that isThermally Protected appearing on the nameplate of a motor or motor- grounded; for ungrounded circuits, the greatest voltage between thecompressor indicate that the motor is provided with a thermal given conductor and any other conductor of the circuit.protector. Watertight. Constructed so that moisture will not enter the Thermal Protector (as applied to motors). A protective device for enclosure under specified test conditions.assembly as an integral part of a motor or motor-compressor that,when properly applied, protects the motor against dangerous Weatherproof. Constructed or protected so that exposure to theoverheating due to overload and failure to start. weather will not interfere with successful operation. FPN: The thermal protector may consist of one or more sensing elements integral with the motor or motor-compressor and an external control device. FPN: Rainproof, raintight, or watertight equipment can fulfill the requirements for weatherproof where varying weather conditions other than wetness, such as snow, ice, dust, or temperature extremes, are not a factor. Utilization Equipment. Equipment that utilizes electric energy forelectronic, electromechanical, chemical, heating, lighting, or similar 1.1.2 Over 600 Volts, Nominalpurposes. Whereas the preceding definitions are intended to apply wherever the Ventilated. Provided with a means to permit circulation of air terms are used throughout this Code, the following definitions aresufficient to remove an excess of heat, fumes, or vapors. applicable only to parts of the article specifically covering installations and equipment operating at over 600 volts, nominal. Volatile Flammable Liquid. A flammable liquid having a flashpoint below 38°C, or a flammable liquid whose temperature is above Electronically Actuated Fuse. An overcurrent protective device thatits flash point, or a Class II combustible liquid that has a vapor generally consists of a control module that provides current sensing,pressure not exceeding 276 kPa at 38°C and whose temperature is electronically derived time–current characteristics, energy to initiateabove its flash point. tripping, and an interrupting module that interrupts current when an overcurrent occurs. Electronically actuated fuses may or may not Voltage (of a circuit). The greatest root-mean-square (rms) operate in a current-limiting fashion, depending on the type of control(effective) difference of potential between any two conductors of the selected.circuit concerned. Fuse. An overcurrent protective device with a circuit-opening FPN: Some systems, such as 3-phase 4-wire, single-phase 3-wire, and 3-wire direct current, may have various circuits of various voltages. fusible part that is heated and severed by the passage of overcurrent
  13. 13. through it. carrier, or disconnecting blade. The fuseholder or fuse carrier may include a conducting element (fuse link) or may act as the FPN: A fuse comprises all the parts that form a unit capable of performing the disconnecting blade by the inclusion of a nonfusible member. prescribed functions. It may or may not be the complete device necessary to connect it into an electrical circuit. Disconnecting (or Isolating) Switch (Disconnector, Isolator). A Controlled Vented Power Fuse. A fuse with provision for mechanical switching device used for isolating a circuit or equipmentcontrolling discharge circuit interruption such that no solid material from a source of power.may be exhausted into the surrounding atmosphere. Disconnecting Means. A device, group of devices, or other means FPN: The fuse is designed so that discharged gases will not ignite or damage whereby the conductors of a circuit can be disconnected from their insulation in the path of the discharge or propagate a flashover to or between source of supply. grounded members or conduction members in the path of the discharge where the distance between the vent and such insulation or conduction members conforms to manufacturer’s recommendations. Interrupter Switch. A switch capable of making, carrying, and interrupting specified currents. Expulsion Fuse Unit (Expulsion Fuse). A vented fuse unit inwhich the expulsion effect of gases produced by the arc and lining of Oil Cutout (Oil-Filled Cutout). A cutout in which all or part of thethe fuseholder, either alone or aided by a spring, extinguishes the arc. fuse support and its fuse link or disconnecting blade is mounted in oil with complete immersion of the contacts and the fusible portion of the Nonvented Power Fuse. A fuse without intentional provision for the conducting element (fuse link) so that arc interruption by severing ofescape of arc gases, liquids, or solid particles to the atmosphere during the fuse link or by opening of the contacts will occur under oil.circuit interruption. Oil Switch. A switch having contacts that operate under oil (or Power Fuse Unit. A vented, nonvented, or controlled vented fuse askarel or other suitable liquid).unit in which the arc is extinguished by being drawn through solidmaterial, granular material, or liquid, either alone or aided by a spring. Regulator Bypass Switch. A specific device or combination of devices designed to bypass a regulator. Vented Power Fuse. A fuse with provision for the escape of arcgases, liquids, or solid particles to the surrounding atmosphere duringcircuit interruption. ARTICLE 1.2 — PERMITS AND INSPECTION CERTIFICATES Multiple Fuse. An assembly of two or more single-pole fuses. 1.2.1 Electrical Permits Switching Device. A device designed to close, open, or both, one ormore electric circuits. Electrical Permit Needed Before Work is Started. Before starting any installation work, alternation, repair or extension on any Circuit Breaker. A switching device capable of making, carrying, electrical system, the owners, lessors, operators, occupants, or licensedand interrupting currents under normal circuit conditions, and also of electrical practitioners shall obtain Electrical Permit for buildings,making, carrying for a specified time, and interrupting currents under trailers, mobile homes, or other premises from the Office of the Localspecified abnormal circuit conditions, such as those of short circuit. Building Official, and for watercrafts from the Maritime Industry Authority (Marina). In securing the electrical permit, the services of a Cutout. An assembly of a fuse support with either a fuseholder, fuse
  14. 14. licensed electrical practitioner is required under the New Electrical Licensed Electrical Practitioner in-charge of the design, and theEngineering Law (RA 7920). licensed electrical practitioner in-charge of the installation shall post a copy of their respective Professional Regulation Commission (PRC) Requirement for Electrical Permit: Signatures and identification card together with the electrical permit at all times.submittals. 1.2.2 Electrical Inspection (a) The Electrical Permit shall include the following minimuminformation: Application for Inspection. An application for inspection shall be filed with the government authority concerned before a 1. Applicant. preliminary and/or final inspection is done. 2.Professional Electrical Engineer who signed and sealedelectrical plans and specifications. Certificate of Inspection. No electrical installation, 3. Licensed Electrical Practitioner who is in-charge of electrical alteration, and/or addition shall be connected or reconnected to anyworks. power supply or any other source of electrical energy without a 4. Building Owner. Certificate of Final Electrical Inspection/Completion obtained from 5. Lot Owner. the local building official signed by their respective licensed electrical 6. Building Official practitioner. (b) Five (5) sets of complete electrical plans and specifications 1.2.3 Specialsigned and sealed by Professional Electrical Engineer. Temporary Installation. For temporary electrical installation, Electrical Permit to Be Issued Immediately. the same procedure as stated above shall be followed. At the end of the period covered by the certificate of inspection, the temporary (a) The application, upon receipt, shall be checked immediately by installation shall be removed. Extended use of the temporarythe local building official or his representatives for compliance with installation shall require a new approval electrical permit.the requirements. If complying, the Electrical Permits shall be issuedupon payment of the corresponding electrical fees. Special Permission Required. Electrical equipment and wiring not specifically covered or mentioned in the various articles of (b) If the project is extensive and required more time for checking this Code shall require special permission and written approval of aand for computations of fees, the issuance of the Electrical Permit licensed electrical practitioner under the enforcing governmentneed not be issued immediately. The delay shall not be longer than authority concerned, prior to installation.five (5) working days after which time application together with theaccompanying plans shall be considered as complying with all the Reconnection of Disconnected Services. In cases whererequirement and the electrical permit shall be issued immediately service has been cut off for more than one (1) year, a new certificate ofthereafter. final electrical inspection shall be required before reconnection. Posting of Electrical Permit. A copy of the Electrical Permit,upon issuance, shall be posted at a conspicuous location at the job siteand shall not be removed until final inspection and approval of thework shall have been made.
  15. 15. 1.3.1 General (2) Location of service drop, service equipment and nearest pole1.3.1.1 Drawing Sheet Sizes. of the utility company furnishing electrical energy; location of the meter as well as sizes of service entrance wires, conduits and service (a) Electrical plans and drawings shall be drawn on drawing sheets equipment; andof the following standard sizes: (3) Clearance of the path or run of service drops and entrance 760 mm x 1 000 mm wires to adjacent existing and/or proposed structures. 600 mm x 900 mm 500 mm x 760 mm (b) Legend or Symbols. Refer to Appendix A – Electrical Symbols (b) In cases such as projects of large magnitude, exemption in the (c) General Notes and/or Specifications. General Notes and/oruse of the standard drawing sheets may be granted by the office of the Specifications, written on the plans or submitted on separate standardlocal building official. Refer to Appendix E. size sheets shall show: (c) For a dwelling unit having a floor area of not more than 50 (1) Nature of electrical service, including number of phases,square meters with a total load not exceeding 3 680 VA, a drawing number of wires, voltage and frequency;sheet of size 297 mm x 420 mm (A3 size) is permitted. (2) Type of wiring; Drawing Scale. Appropriate metric drawing scales shall beused. a. Service entrance b. Feeders, sub-feeders and branch circuit wires for lighting1.3.1.3. Graphic Scale. Since the size of the drawing sheet can be and/or power loadchanged photographically, graphic scale shall be shown on each c. Fire alarm system, if required by lawdrawing sheet. d. Signaling and communication FPN: Graphic scale denotes nominal or average plan scale and remains true when (3) Special equipment to be installed, indicating ratings and plans are photographically reduced. classification of service or duty cycle of; a. Rectifiers 1.3.2 Plans and Specifications b. Heaters c. X-ray apparatus1.3.2.1 Plan Requirements. d. Electric welding equipment e. Others (a) Location and Site Plans. Location and site plans, with proposedstructure and owner’s land drawn to appropriate metric scale shall (4) System or method of grounding;show: (5) Type and rating of main disconnecting means, overcurrent (1) Bordering areas showing public or well-known streets, protection (OCP) and branch circuit wiring;landmarks and/or structures which need not be drawn to scale unlessthey extend into the area concerned; (6) Clearances of service drop, burial depth for service lateral,
  16. 16. mounting height and clearance for service equipment, mounting heightand clearance for kWh meter. a. Location of outlets, equipment and/or apparatus and controls; b. Complete circuit showing no. and size of raceway and wire; (d) Electrical Layout. Floor plan showing location of equipmentand devices, and their interconnection wiring. (e) Schedule of Loads. Schedule of load in tabulated form shall indicate: (1) Plan for Power. Layout and wiring plans for power on thefloor plans drawn to scale, shall show: (1) Motor Loads; a. Sizes and location of service entrance conductors, raceways, a. Motors as numbered or identified in power layoutmetering equipment, main switchboard, layout of feeders and b. Type of motordistribution panels or switches and their sizes, types and ratings; c. Horsepower/kilowatt/kilovolt ampere rating b. Complete circuits of motors and other electrical equipment, d. Voltage ratingtheir controlling devices, their locations and ratings; e. Full-load current rating c. Complete wiring of emergency power system, if any; f. Frequency rating other than 60 hertz d. Nature of processes/activities carried out in each room or area g. Number of phases h. Type and size of wiring FPN: In residences, apartment houses and small commercial establishments, i. Protective device rating layout of equipment and motors of one horsepower or less may be incorporated in the layout for General Lighting and Receptacle Outlets. In general, layout of motors and power outlets not exceeding a total of ten, may be included in the lighting (2) Lighting and Receptacle Loads; layout provided such inclusion will not make reading, interpretation and/or checking of said plan difficult. a. Panel as numbered in the feeder diagram (2) Plan for Lighting and Receptacle Outlets. Layout and wiring b. Circuit designation numberplans for general lighting and receptacle outlets on floor plans drawn c. Number of lighting outlets in each circuitto scale, shall show: d. Number of switches in each circuit e. Number of receptacles outlets (convenience outlets) a. Location, type and rating of lighting fixtures, indicating f. Voltage of circuitillumination in lux in each room or area. In residences, hotels, g. Type and size of wiringapartment houses, and churches, the illumination level in each room or h. Protective device ratingarea need not be shown nor computed; b. Location of switches for each fixtures or group of fixtures; (3) Other Loads. c. Location of receptacle outlets and appliances to be served andtheir ratings; a. Designation number on plan d. Complete circuits of the lighting and receptacle outlets; b. Description of load e. Complete wiring of emergency lighting system, if any; c. Classification of service duty, if required f. A separate drawing showing layout of receptacle outlets may d. Rating of kilovolt-ampere or kilowattbe made at the discretion of the design engineer. e. Phase loading indicating full load line current f. Voltage rating (3) Plan for Fire Alarm Circuits. Layout and wiring plans of fire g. Type and size of wiringalarm station, fire alarm bell, fire alarm control panel, and other shall h. Protective device ratingbe drawn to scale and show:
  17. 17. (f) Design Analysis. Design analysis shall be included on the the conductordrawings or shall be submitted on separate sheets of standard size, andshall show: (4) Load Center. (1)Branch circuits, sub-feeders, feeders, busways, and service a. Identification and/or labeling of load center showing type andentrance; rating of transformer, switches, circuit breaker and other related devices (2) Types, ratings, and trip settings of overload protective devices; b. Incoming and outgoing feeders, type, size and voltage c. Equipment grounding (3) Calculation of short circuit current for determining theinterrupting capacity of overurrent protection device for residential, Title Block. Title block or nameplate of plans and drawingcommercial, and industrial establishment; shall be a standard strip of 40 mm high at the bottom of the sheet. It shall contain the following: (4) Calculation of voltage drops. (a) Name and location of installation or project; (g) One Line Diagram. One line diagram shall indicate: (b) Name, signature and address of owner/manager/operator; (1) Lighting and Receptacle Outlet Loads; (c) Title of sheet; a. Single line or schematics diagram of lighting and receptaclespanelboards showing mains and branch circuit rating; (d) Name, signature and seal of Professional Electrical Engineer b. Size of conductors for feeders. together with Professional Regulation Commission professional license number and validity, Professional Tax Receipt Number, and (2) Motor Loads; Tax Identification Number; a. Rating in kilowatts/horsepower/kilovolt ampere (e) Scale used, date drawn; and b. Full load current c. Locked rotor current (f) Sheet number. d. Phase connection for 1-phase motor on a 3-phase system e. Rated voltage Other Details. f. Type and size of wiring, indicating load in amperes g. Electric motors shall be numbered consecutively to (a) Exposed conductors shall show:correspond to their numbers in the layout (1) Means of support and types of insulators; and (3) Feeders and Subfeeders; (2) Spacings and clearances. a. Identification and/or labeling of feeders and subfeeders b. Size and type of wires and raceway (b) Auxiliary gutters, wireways, busways, cabinets, boxes, c. Protective devices and controls metallic raceways, underground installations, other than specified d. The allowable ampacity of the conductor over the designed in the Code shall show:load current in amperes expressed as a ratio and indicated along side
  18. 18. (1) Installation details; (1) Materials and construction of walls, floors, roof, windows, (2) Conductor supports, separators, and attachments where enclosures, doors, and their dimensions, andrequired by this Code; and (2) Ventilation and drainage systems and other safeguards. (3) Dimensions and description or specifications. (c) Substation electrical requirements such as; (c) Private pole installations shall show: (1) Plan view showing location and sizes of equipment installed, (1) Construction and installation details and dimensions; (2) Clearances and spacings between exposed current-carrying and (2) Pole top wiring details including line hardware; and noncurrent-carrying portions and grounding equipment, and (3) Guying details. (3) Grounding system. (d) Low energy power and low voltage power installation shall (d) Cross sectional views showing;show: (1) Horizontal and vertical clearances between exposed parts and (1) Details of battery installation and/or other source of low adjacent surfaces,voltage or low energy power; (2) Horizontal and vertical clearances of exposed parts from (2) Equipment, wiring, actuating mechanism and protective floor/ceiling,devices; and (3) Finished floor level and ground level. (3) Ventilation details whenever necessary. (e) Miscellaneous; 1.3.3 Substation Plans and Specifications (1) Specification of equipment, Indoor Substation. Indoor substation plans shall show: (2) Wiring of lighting and remote control systems, (a) Location and dimensions of; (3) One-line diagram(s) of entire installation with voltage (1) Substation in building plan drawn to scale, indicated, (2) Building with respect to entire compound or property, (4) Computations on size of wires, busbar, transformer, fuses, switches and breaker, and (3) Incoming and outgoing lines, and (5) Class of insulation or insulators. (4) Windows, doors, and other openings. Outdoor Substation. Outdoor substation plans shall show (b) Substation structural requirements; same items as indoor substation except that in lieu of walls and roof,
  19. 19. details of fence and supporting steel structure shall be shown inaccordance with the latest edition of the Philippine Electrical Code, (5) Heating effects under normal conditions of use and also underPart 2. abnormal conditions likely to arise in service (6) Arcing effects ARTICLE 110 — REQUIREMENTS FOR ELECTRICAL INSTALLATIONS (7) Classification by type, size, voltage, current capacity, and specific use 1.10.1 General (8) Other factors that contribute to the practical safeguarding of1.10.1.1 Scope. This article covers general requirements for the persons using or likely to come in contact with the equipmentexamination and approval, installation and use, access to and spacesabout electrical conductors and equipment; enclosures intended for (b) Installation and Use. Listed or labeled equipment shall bepersonnel entry; and tunnel installations. installed and used in accordance with any instructions included in the listing or labeling. Approval. The conductors and equipment required orpermitted by this Code shall be acceptable only if approved. Voltages. Throughout this Code, the voltage considered shall be that at which the circuit operates. The voltage rating of electrical FPN: See, Examination of Equipment for Safety, and, equipment shall not be less than the nominal voltage of a circuit to Examination, Identification, Installation, and Use of Equipment. See definitions of Approved, Identified, Labeled, and Listed. which it is connected. Examination, Identification, Installation, and Use of Conductors. Conductors normally used to carry current shallEquipment. be of copper unless otherwise provided in this Code. Where the conductor material is not specified, the material and the sizes given in (a) Examination. In judging equipment, considerations such as the this Code shall apply to copper conductors. Where other materials arefollowing shall be evaluated: used, the size shall be changed accordingly. FPN: For aluminum and copper-clad aluminum conductors, see (1) Suitability for installation and use in conformity with theprovisions of this Code Conductor Sizes. Conductor sizes are expressed in square FPN: Suitability of equipment use may be identified by a description marked on or millimetres (mm2) for stranded or in millimetres diameter (mm dia.) provided with a product to identify the suitability of the product for a specific for solid. purpose, environment, or application. Suitability of equipment may be evidenced by listing or labeling. Insulation Integrity. Completed wiring installations shall be (2) Mechanical strength and durability, including, for parts free from short circuits and from grounds other than as required ordesigned to enclose and protect other equipment, the adequacy of the permitted in Article thus provided Wiring Methods. Only wiring methods recognized as (3) Wire-bending and connection space suitable are included in this Code. The recognized methods of wiring shall be permitted to be installed in any type of building or occupancy, (4) Electrical insulation except as otherwise provided in this Code.
  20. 20. Interrupting Rating. Equipment intended to interrupt current (a) Unused Openings. Unused cable or raceway openings in boxes,at fault levels shall have an interrupting rating sufficient for the raceways, auxiliary gutters, cabinets, cutout boxes, meter socketnominal circuit voltage and the current that is available at the line enclosures, equipment cases, or housings shall be effectively closed toterminals of the equipment. afford protection substantially equivalent to the wall of the equipment.Equipment intended to interrupt current at other than fault levels shall Where metallic plugs or plates are used with nonmetallic enclosures,have an interrupting rating at nominal circuit voltage sufficient for the they shall be recessed at least 6 mm from the outer surface of thecurrent that must be interrupted. enclosure. Circuit Impedance and Other Characteristics. The (b) Subsurface Enclosures. Conductors shall be racked to provideovercurrent protective devices, the total impedance, the component ready and safe access in underground and subsurface enclosures intoshort-circuit current ratings, and other characteristics of the circuit to which persons enter for installation and protected shall be selected and coordinated to permit the circuit-protective devices used to clear a fault to do so without extensive (c) Integrity of Electrical Equipment and Connections. Internaldamage to the electrical components of the circuit. This fault shall be parts of electrical equipment, including busbars, wiring terminals,assumed to be either between two or more of the circuit conductors or insulators, and other surfaces, shall not be damaged or contaminatedbetween any circuit conductor and the grounding conductor or by foreign materials such as paint, plaster, cleaners, abrasives, orenclosing metal raceway. Listed products applied in accordance with corrosive residues. There shall be no damaged parts that maytheir listing shall be considered to meet the requirements of this adversely affect safe operation or mechanical strength of thesection. equipment such as parts that are broken; bent; cut; or deteriorated by corrosion, chemical action, or overheating. Deteriorating Agents. Unless identified for use in theoperating environment, no conductors or equipment shall be located in Mounting and Cooling of Equipment.damp or wet locations; where exposed to gases, fumes, vapors, liquids,or other agents that have a deteriorating effect on the conductors or (a) Mounting. Electrical equipment shall be firmly secured to theequipment; or where exposed to excessive temperatures. surface on which it is mounted. Wooden plugs driven into holes in masonry, concrete, plaster, or similar materials shall not be used. FPN No. 1: See for protection against corrosion. FPN No. 2: Some cleaning and lubricating compounds can cause severe (b) Cooling. Electrical equipment that depends on the natural deterioration of many plastic materials used for insulating and structural circulation of air and convection principles for cooling of exposed applications in equipment. surfaces shall be installed so that room airflow over such surfaces is not prevented by walls or by adjacent installed equipment. ForEquipment identified only as “dry locations,” “Type 1,” or “indoor use equipment designed for floor mounting, clearance between toponly” shall be protected against permanent damage from the weather surfaces and adjacent surfaces shall be provided to dissipate risingduring building construction. warm air. Electrical equipment provided with ventilating openings shall be1.10.1.12 Mechanical Execution of Work. Electrical equipment shall installed so that walls or other obstructions do not prevent the freebe installed in a neat and workmanlike manner. circulation of air through the equipment. FPN: Accepted industry practices are described in ANSI/NECA 1-2000, Standard Practices for Good Workmanship in Electrical Contracting, and other ANSI- Electrical Connections. Because of different characteristics approved installation standards. of dissimilar metals, devices such as pressure terminal or pressure