UL COPYRIGHTED MATERIAL –
NOT AUTHORIZED FOR FURTHER REPRODUCTION OR
DISTRIBUTION WITHOUT PERMISSION FROM UL
14.4 Friction between surfaces is not acceptable as a means to prevent shifting or turning of a live part,
but a lock washer properly applied is acceptable.
15 Internal Wiring
15.1 General
15.1.1 The internal wiring of a converter or inverter shall be of a type and size acceptable for the
application as specified in this section. Other types of wiring may be acceptable based on temperature,
voltage, and the need for mechanical protection.
15.1.1 effective April 13, 1993
15.1.2 The thickness of insulation on wiring shall not be less than 3/64 inch (1.2 mm) for unbraided
neoprene-insulated wire, 1/32 inch (0.8 mm) for thermoplastic-insulated wire, and 1/32 inch for
rubber-insulated wire with an impregnated braid.
15.1.3 Unless a converter or inverter includes a resistor or other heat-producing component and wire is
subjected to a temperature of more than 80°C (176°F), or other need is demonstrated, Type AF or CF
wire shall not be employed.
15.1.3 effective April 13, 1993
15.1.4 The length of the power-supply cord inside a converter or inverter shall not be more than the need
for the electrical connections.
15.1.4 effective April 13, 1993
15.1.5 The jacket of a flexible cord inside the enclosure shall not be stripped to expose the individual
conductors unless:
a) The insulation on the individual conductors is equivalent to that required by 15.1.2;
b) The individual conductors are supported in a manner positively separating them from live parts
and dead metal parts; or
c) Supplementary insulation equivalent to that required by 15.1.2 is reliably secured on each
individual conductor.
15.2 Tubing
15.2.1 Insulation of internal wiring consisting of coated fabric, thermoplastic, or other types of tubing is to
be considered with respect to electrical, mechanical, and flammability properties of the material.
15.2.2 If the use of a short length of insulated conductor, such as a short coil lead, is not practical,
electrical insulating tubing may be used on each conductor. The tubing shall not be subjected to sharp
bends, tension, compression, or repeated flexing, or to contact with sharp edges, projections, or corners.
Except as noted in 15.2.3, the wall thickness shall comply with the requirements for the tubing as a
component.
15.2.3 Polyvinyl chloride tubing shall not be less than 0.017 inch (0.43 mm) thick at any point. The
thickness of insulating tubing of other types, shall provide mechanical strength, flame resistance, dielectric
properties, and heat- and moisture-resistant characteristics, and the like that are at least equivalent to
those of 0.017-inch-thick polyvinyl chloride tubing.
DECEMBER 14, 1993UL 45828
To Next Page