The disconnecting means shall be located so as to be accessible to qualified persons before servicing or maintaining the ballast Where the disconnecting means is external to the luminaire, it shall be a single device, and shall be attached to the luminaire or the luminaire shall be located within sight of the disconnecting means.
410.134 Direct-Current Equipment. Luminaires installed on dc circuits shall be equipped with auxiliary equipment and resistors designed for dc operation. The luminaires shall be marked for dc operation.
410.135 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 designed so that there will be
no exposed live parts when lamps are being inserted,
are in place, or are being removed.
410.136 Luminaire Mounting.
(A) Exposed Ballasts. Luminaires that have exposed ballasts or transformers shall be installed such that such ballasts or transformers will not be in contact with combustible material.
(B) Combustible Low-Density Cellulose Fiberboard. Where a surface-mounted luminaire containing a ballast is to be installed on combustible low-density cellulose fiber-board, it shall be marked for this condition or shall be spaced not less than 38 mm (1 Vi in.) from the surface of the fiberboard. Where such luminaires are partially or wholly recessed, the provisions of 410.110 through 410.122 shall apply.
FPN: Combustible low-density cellulose fiberboard in- cludes sheets, panels, and tiles that have a density of
320 kg/m 3 (20 lb/ft 3) or less and that are formed of
bonded plant fiber material but does not include solid
or laminated wood or fiberboard that has a density in excess of 320 kg/m 3 (20 lb/ft 3) 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 ANSI/ASTM E84-1997, Test Method for Surface Burning Characteristics of Building Materials.
410.137 Equipment Not Integral with Luminaire.
(A) Metal Cabinets. Auxiliary equipment, including reactors, capacitors, resistors, and similar equipment, where not installed as part of a luminaire 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 Luminaire Sections. Wired luminaire 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 metric designator 12 (trade size 3/s) flexible metal conduit in lengths not exceeding
7.5 m (25 ft), in conformance with Article 348. Luminaire wire operating at line voltage, supplying only the ballast(s) of one of the paired luminaires shall be permitted in the same raceway as the lamp supply wires of the paired luminaires.