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6.12 Material supporting terminals or used as internal electrical insulation of an electrical instrument shall
comply with the requirements in Section 16, Insulating Materials.
Exception: An electrical instrument connected in a secondary circuit need not comply with this
requirement if damage to or deterioration of the materials will not result in a risk of electric shock or fire.
6.13 Supporting feet of a converter or inverter that form part of the enclosure or are needed for ventilation
shall be reliably secured and the resistance to aging, physical properties, and resistance to combustion of
the material shall be investigated.
6.13 effective April 13, 1993
6.14 A compartment or part of an enclosure that will contain field-wiring splices in other than a Class 2
circuit shall not be provided with ventilating openings.
6.14 revised October 15, 2004
6.15 The enclosure of a converter or inverter shall be such as to prevent molten metal, burning insulation,
flaming particles, or the like from falling on combustible materials, including the surface upon which the
converter or inverter is supported. See Section 49, Burnout Test.
6.15 effective April 13, 1993
6.16 If a screen is needed in the bottom of an enclosure to comply with the requirements in 6.18 and 6.19,
it shall be 14 mesh steel with a minimum wire diameter of 0.018 inch (0.46 mm) and shall be mechanically
secured in position.
6.17 For a converter or inverter having holes in the bottom of the enclosure, the requirements in 6.15 will
necessitate the use of:
a) Internal wiring insulated with neoprene, thermoplastic, or glass fiber, or an equally fire-
retardant material.
b) An individually enclosed fuse, such as an extractor type. Consideration will be given to a
fuse enclosed with a transformer winding.
6.17 effective April 13, 1993
Table 6.2
Knockout or hole sizes and dimensions of bushings
Table 6.2 relocated as Table 11.1 October 15, 2004
6.18 A component having a magnetic winding or coil, such as a relay or a solenoid, shall be individually
and completely enclosed, or subjected to the burnout tests described in 49.1.1 and 49.2.1.
6.19 Arcing parts of a switch or relay located in an enclosure having ventilating openings in the bottom
shall be individually and completely enclosed, or the switch or relay shall be subjected to the arcing
overload test described in 49.3.4.
OCTOBER 15, 2004 UL 458 15
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