Arc lamps used on constant-current systems shall comply

with the general requirements of Article 710. L. Receptacles, Cord Connectors, and Attachment Plugs (Caps) 410-56. Rating and Type. (a) Receptacles. Receptacles installed for the attachment of portable cords shall be rated at not less than 15 amperes, 125 volts, or 15 amperes, 250 volts, and shall be of a type not suitable for use as lampholders. Exception: The use of receptacles of 10-ampere, 250-volt rating used in nonresidential occupancies for the supply of equipment other than portable hand tools, portable handlamps, and extension cords shall be permitted. (b) CO/ALR Receptacles. Receptacles rated 20 amperes or less and directly connected to aluminum conductors shall be marked CO/ALR. (c) Isolated Ground Receptacles. Receptacles intended for the reduction of electrical noise (electromagnetic interference) as permitted in Section 250-74, Exception No. 4 shall be identified by an orange color or an orange triangle located on the face of the receptacle. (d) Faceplates. Metal faceplates shall be of ferrous metal not less than 0.030 inch (762 micrometers) in thickness or of nonferrous metal not less than 0.040 inch (1 mm) in thickness. Metal faceplates shall be grounded. Faceplates of insulating material shall be noncombustible and not less than 0.10 inch (2.54 mm) in thickness but shall be permitted to be less than 0.10 inch (2.54 mm) in thickness if formed or reinforced to provide adequate mechanical strength. (e) Position of Receptacle Faces. After installation, receptacle faces shall be flush with or project from faceplates of insulating material and shall project a minimum of 0.015 inch (381 micrometers) from metal faceplates. Faceplates shall be installed so as to completely cover the opening and seat against the mounting surface. Receptacles mounted in boxes that are set back of the wall surface, as permitted in Section 370-20, shall be installed so that the mounting yoke or strap of the receptacle is held rigidly at the surface of the wall. Receptacles mounted in boxes that are flush with the wall surface or project therefrom shall be so installed that the mounting yoke or strap of the receptacle is seated against the box or raised box cover. (f) Attachment Plugs. All 15- and 20-ampere attachment plugs and connectors shall be so constructed that there are no exposed current-carrying parts except the prongs, blades, or pins. The cover for wire terminations shall be a part, which is essential for the operation of an attachment plug or connector (dead-front construction). 70-344 NATIONAL ELECTRICAL CODE (g) Attachment Plug Ejector Mechanisms. Attachment plug ejector mechanisms shall not adversely affect engagement of the blades of the attachment plug with the contacts of the receptacle. (h) Noninterchangeability. Receptacles, cord connectors, and attachment plugs shall be constructed SO that the receptacle or cord connectors will not accept an attachment plug with a different voltage or current rating than that for which the device is intended. Nongrounding-type receptacles and connectors shall not accept grounding-type attachment plugs. Exception: A 20-ampere T-slot receptacle or cord connector shall be permitted to accept a 15-ampere attachment plug of the same voltage rating. (i) Receptacles in Raised Covers. Receptacles installed in raised covers shall not be secured solely by a single screw. Exception: Devices or assemblies listed and identified for such use. 410-57. Receptacles in Damp or Wet Locations. (a) Damp Locations. A receptacle installed outdoors in a location protected from the weather or in other damp locations shall have an enclosure for the receptacle that is weatherproof when the receptacle is covered (attachment plug cap not inserted and receptacle covers closed). An installation suitable for wet locations shall also be considered suitable for damp locations. A receptacle shall be considered to be in a location protected from the weather where located under roofed open porches, canopies, marquees, and the like, and will not be subjected to a beating rain or water run-off. (b) Wet Locations. A receptacle installed outdoors where exposed to weather or in other wet locations shall be in a weatherproof enclosure, the integrity of which is not affected when the receptacle is in use (attachment plug cap inserted). Exception: An enclosure that is weatherproof only when a self-closing receptacle cover is closed shall be permitted to be used for a receptacle installed outdoors where the receptacle. is provided for use with portable tools or other portable equipment normally connected to the outlet only when attended. (c) Protection for Floor Receptacles. Standpipes of floor receptacles shall allow floor-cleaning equipment to be operated without damage to receptacles. (d) Flush Mounting with Faceplate. The enclosure for a receptacle installed in an outlet box flush-mounted on a wall surface shall be made weatherproof by means of a weatherproof faceplate assembly that provides a watertight connection between the plate and the wall surface. (e) Installation. A receptacle outlet installed outdoors shall be located so that water accumulation is not likely to touch the outlet cover or plate. ARTICLE 410 - LIGHTING FIXTURES, ETC. 70-345 410-58. Grounding-type Receptacles, Adapters, Cord Connectors, and Attachment Plugs. (a) Grounding Poles. Grounding-type receptacles, cord connectors, and attachment plugs shall be provided with one fixed grounding pole in addition to the circuit poles. Exception: The grounding contacting pole of grounding-type attachment plugs on the power-supply cords of portable hand-held, hand-guided, or hand-supported tools or appliances shall be permitted to be of the movable, self-restoring type on circuits operating at not over 150 volts between any two conductors nor over 150 volts between any conductor and ground. (b) Grounding-Pole Identification. Grounding-type receptacles, adapters, cord connections, and attachment plugs shall have a means for connection of a grounding conductor to the grounding pole. A terminal for connection to the grounding pole shall be designated by: (1) A green-colored hexagonal-headed or shaped terminal screw or nut, not readily removable; or (2) A green-colored pressure wire connector body (a wire barrel); or (3) A similar green-colored connection device, in the case of adapters. The grounding terminal of a grounding adapter shall be a green-colored rigid ear, lug, or similar device. The grounding connection shall be so designed that it cannot make contact with current-carrying parts of the receptacle, adapter, or attachment plug. The adapter shall be polarized. (4) If the terminal for the equipment grounding conductor is not visible, the conductor entrance hole shall be marked with the word "green" or otherwise identified by a distinctive green color. (c) Grounding Terminal Use. A grounding terminal or grounding-type device shall not be used for purposes other than grounding. (d) Grounding-Pole Requirements. Grounding-type attachment plugs and mating cord connectors and receptacles shall be so designed that the grounding connection is made before the current-carrying connections. Grounding-type devices shall be designed so grounding poles of attachment plugs cannot be brought into contact with current-carrying parts of receptacles or cord connectors. (e) Use. Grounding-type attachment plugs shall be used only where an equipment ground is to be provided. M. Special Provisions for Flush and Recessed Fixtures 410-64. General. Fixtures installed in recessed cavities in walls or ceilings shall comply with Sections 410-65 through 410-72. 410-65. Temperature. (a) Combustible Material. Fixtures shall be so installed that adjacent combustible material will not be subjected to temperatures in excess of 90°C (194°F). (b) Fire-Resistant Construction. Where a fixture is recessed in fireresistant material in a building of fire-resistant construction, a temperature 70-346 NATIONAL ELECTRICAL CODE higher than 90°C (194°F), but not higher than 150°C (302°F), shall be considered acceptable if the fixture is plainly marked that it is listed for that service. (c) Recessed Incandescent Fixtures. Incandescent fixtures shall have thermal protection and shall so be identified as thermally protected. Exception No. 1: Recessed incandescent fixtures identified for use and installed in poured concrete. Exception No. 2: Listed recessed incandescent fixtures that provide, by construction design, the equivalent temperature performance characteristics of thermally protected fixtures and are so identified. 410-66. Clearance and Installation. (a) Clearance. Recessed portions of lighting fixture enclosures, other than at the points of support, shall be spaced at least 1/2 inch (12.7 mm) from combustible materials. Exception: Recessed fixtures identified as suitable for insulation to be in direct contact with the fixture. (b) Installation. Thermal insulation shall not be installed within 3 inches (76 mm) of the recessed fixture enclosure, wiring compartment, or ballast, and shall not be so installed above the fixture so as to entrap heat and prevent the free circulation of air. Exception: Recessed fixtures identified as suitable for insulation to be in direct contact with the fixture. 410-67. Wiring. (a) General. Conductors having insulation suitable for the temperature encountered shall be used. (b) Circuit Conductors. Branch-circuit conductors having an insulation suitable for the temperature encountered shall be permitted to terminate in the fixture. (c) Tap Conductors. Tap conductors of a type suitable for the temperature encountered shall be permitted to run from the fixture terminal connection to an outlet box placed at least 1 foot (305 mm) from the fixture. Such tap conductors shall be in suitable raceway or Type AC or MC cable of at least 4 feet (1.22 m) but not more than 6 feet (1.83 m) in length. N. Construction of Flush and Recessed Fixtures 410-68. Temperature. Fixtures shall be so constructed that adjacent combustible material will not be subject to temperatures in excess of 90°C (194°F). 410-69. Housing. Sheet metal of flush and recessed fixture housings shall be protected against corrosion and shall not be less than No. 22 MSG. Exception: A wiring compartment cover shall be permitted to be of a thinner material provided it is within the No. 22 MSG housing and does not support any current-carrying components. ARTICLE 410 - LIGHTING FIXTURES, ETC. 70-347 410-70. Lamp Wattage Marking. Incandescent lamp fixtures shall be marked to indicate the maximum allowable wattage of lamps. The markings shall be permanently installed, in letters at least 1/4 inch (6.35 mm) high, and shall be located where visible during relamping. 410-71. Solder Prohibited. No solder shall be used in the construction of a fixture box. 410-72. Lampholders. Lampholders of the screw-shell type shall be of porcelain or other suitable insulating materials. Where used, cements shall be of the high-heat type. P. Special Provisions for Electric-Discharge Lighting Systems of 1000 Volts or Less 410-73. General. (a) Open-Circuit Voltage of 1000 Volts or Less. Equipment for use with electric-discharge lighting systems and designed for an open-circuit voltage of 1000 volts or less shall be of a type intended for such service. (b) Considered as Energized. The terminals of an electric-discharge lamp shall be considered as energized where any lamp terminal is connected to a circuit of over 300 volts. (c) Transformers of the Oil-Filled Type. Transformers of the oil-filled type shall not be used. (d) Additional Requirements. In addition to complying with the general requirements for lighting fixtures, such equipment shall comply with Part P of this article. (e) Thermal Protection. Where fluorescent fixtures are installed indoors, the ballasts shall have thermal protection integral within the ballast. Replacement ballasts for all fluorescent fixtures installed indoors shall also have thermal protection integral within the ballast. Exception No. 1: Fluorescent fixtures using straight tubular lamps with simple reactance ballasts. Exception No. 2: Ballasts for use in exit fixtures and so identified. Exception No. 3: Egress lighting energized only during an emergency. (f) High-Intensity Discharge Fixtures. Recessed high-intensity discharge fixtures shall be thermally protected and shall be so identified. Where fixtures, whether recessed or otherwise, are operated by remote ballasts, the ballasts shall also be thermally protected. Exception: Recessed high-intensity discharge fixtures identified for use and installed in poured concrete. (FPN): The thermal protection required by Section 410-73 may be accomplished by means other than a thermal protector. 410-74. Direct-Current Equipment. Fixtures installed on direct-current circuits shall be equipped with auxiliary equipment and resistors especially designed and for direct-current operation, and the fixtures shall be so marked. 70-348 NATIONAL ELECTRICAL CODE 410-75. Open-Circuit Voltage Exceeding 300 Volts. Equipment having an open-circuit voltage exceeding 300 volts shall not be installed in dwelling occupancies unless such equipment is so designed that there will be no exposed live parts when lamps are being inserted, are in place, or are being removed. 410-76. Fixture Mounting. (a) Exposed Ballasts. Fixtures having exposed ballasts or transformers shall be so installed that such ballasts or transformers will not be in contact with combustible material. (b) Combustible Low-Density Cellulose Fiberboard. Where a surfacemounted fixture containing a ballast is to be installed on combustible lowdensity cellulose fiberboard, it shall be listed for this condition or shall be spaced not less than 1½ inches (38 mm) from the surface of the fiberboard. Where such fixtures are partially or wholly recessed, the provisions of Sections 410-64 through 410-72 shall apply. (FPN): Combustible low-density cellulose fiberboard includes sheets, panels, and tiles that have a density of 20 pounds per cubic foot (320.36 kg/cu m) or less, and that are formed of bonded plant fiber material but does not include solid or laminated wood, nor fiberboard that has a density in excess of 20 pounds per cubic foot (320.36 kg/cu m) or is a material that has been integrally treated with fire-retarding chemicals to the degree that the flame spread in any plane of the material will not exceed 25, determined in accordance with tests for surface burning characteristics of building materials. See Test Method for Surface Burning Characteristics of Building Materials, ANSI/ASTM E84-1984. 410-77. Equipment Not Integral with Fixture. (a) Metal Cabinets. Auxiliary equipment, including reactors, capacitors, resistors, and similar equipment, where not installed as part of a lighting fixture assembly, shall be enclosed in accessible, permanently installed metal cabinets. (b) Separate Mounting. Separately mounted ballasts that are intended for direct connection to a wiring system shall not be required to be separately enclosed. (c) Wired Fixture Sections. Wired fixture sections are paired, with a ballast(s) supplying a lamp or lamps in both. For interconnection between paired units, it shall be permissible to use ³/₈-inch flexible metal conduit in lengths not exceeding 25 feet (7.62 m) in conformance with Article 350. Fixture wire operating at line voltage, supplying only the ballast(s) of one of the paired fixtures, shall be permitted in the same raceway as the lamp supply wires of the paired fixtures. 410-78. Autotransformers. An autotransformer that is used to raise the voltage to more than 300 volts, as part of a ballast for supplying lighting units, shall be supplied only by a grounded system. 410-79. Switches. Snap switches shall comply with Section 380-14. ARTICLE 410 - LIGHTING FIXTURES, ETC. 70-349 Q. Special Provisions for Electric-Discharge Lighting Systems of More than 1000 Volts 410-80. General. (a) Open-Circuit Voltage Exceeding 1000 Volts. Equipment for use with electric-discharge lighting systems and designed for an open-circuit voltage exceeding 1000 volts shall be of a type intended for such service. (b) Dwelling Occupancies. Equipment having an open-circuit voltage exceeding 1000 volts shall not be installed in or on dwelling occupancies. (c) Live Parts. The terminal of an electric-discharge lamp shall be considered as a live part where any lamp terminal is connected to a circuit of over 300 volts. (d) Additional Requirements. In addition to complying with the general requirements for lighting fixtures, such equipment shall comply with Part Q of this article. (FPN): For signs and outline lighting, see Article 600. 410-81. Control. (a) Disconnection. Fixtures or lamp installations shall be controlled either singly or in groups by an externally operable switch or circuit breaker that opens all ungrounded primary conductors. (b) Within Sight or Locked Type. The switch or circuit breaker shall be located within sight from the fixtures or lamps, or it shall be permitted elsewhere if it is provided with a means for locking in the open position. 410-82. Lamp Terminals and Lampholders. Parts that must be removed for lamp replacement shall be hinged or held captive. Lamps or lampholders will be so designed that there shall be no exposed live parts when lamps are being inserted or are being removed. 410-83. Transformer Ratings. Transformers and ballasts shall have a secondary open-circuit voltage of not over 15,000 volts with an allowance on test of 1000 volts additional. The secondary-current rating shall not be more than 120 milliamperes if the open-circuit voltage is over 7500 volts, and not more than 240 milliamperes if the open-circuit voltage is 7500 volts or less. 410-84. Transformer Type. Transformers shall be enclosed and listed. 410-85. Transformer Secondary Connections. The high-voltage windings of transformers shall not be connected in series or in parallel. Exception: Two transformers, each having one end of its high-voltage winding grounded and connected to the enclosure, shall be permitted to have their high-voltage windings connected in series to form the equivalent of a midpoint grounded transformer. The grounded ends shall be connected by insulated conductors not smaller than No. 14. 70-350 NATIONAL ELECTRICAL CODE 410-86. Transformer Locations. (a) Accessible. Transformers shall be accessible after installation. (b) Secondary Conductors. Transformers shall be installed as near to the lamps as practicable to keep the secondary conductors as short as possible. (c) Adjacent to Combustible Materials. Transformers shall be so located that adjacent combustible materials will not be subjected to temperatures in excess of 90°C (194°F). 410-87. Transformer Loading. The lamps connected to any transformer shall be of such length and characteristics as not to cause a condition of continuous overvoltage on the transformer. 410-88. Wiring Method - Secondary Conductors. Conductors shall be installed in accordance with Section 600-31. 410-89. Lamp Supports. Lamps shall be adequately supported as required in Section 600-33. 410-90. Exposure to Damage. Lamps shall not be located where normally exposed to physical damage. 410-91. Marking. Each fixture or each secondary circuit of tubing having an open-circuit voltage of over 1000 volts shall have a clearly legible marking in letters not less than ¼ inch (6.35 mm) high reading "Caution. .volts. The voltage indicated shall be the rated open-circuit voltage. 410-92. Switches. Snap switches shall comply with Section 380-14. R. Lighting Track 410-100. Definition. Lighting track is a manufactured assembly designed to support and energize lighting fixtures that are capable of being readily repositioned on the track. Its length may be altered by the addition or subtraction of sections of track. 410-101. Installation. (a) Lighting Track. Lighting track shall be permanently installed and permanently connected to a branch circuit. Only lighting track fittings shall be installed on lighting track. Lighting track fittings shall not be equipped with general-purpose receptacles. (b) Connected Load. The connected load on lighting track shall not exceed the rating of the track. Lighting track shall be supplied by a branch circuit having a rating not more than that of the track. (c) Locations Not Permitted. Lighting track shall not be installed (1) where subject to physical damage; (2) in wet or damp locations; (3) where subject to corrosive vapors; (4) in storage battery rooms; (5) in hazardous (classified) locations; (6) where concealed; (7) where extended through walls or partitions; (8) less than 5 feet (1.52 m) above the finished floor