UL COPYRIGHTED MATERIAL –
NOT AUTHORIZED FOR FURTHER REPRODUCTION OR
DISTRIBUTION WITHOUT PERMISSION FROM UL
8.1.3 Perforated sheet metal shall not be less than 0.042 inch (1.07 mm) thick if the perforations are 1/2
square inch (3.2 cm
2
) or less in area, and shall not be less than 0.080 inch (2.03 mm) thick for larger
openings.
Exception: Perforated sheet metal not less than 0.020 inch (0.51 mm) thick may be used where the
indentation of a guard or enclosure will not affect the clearance between uninsulated live parts, film-coated
wire, or moving parts and grounded metal.
8.1.3 effective April 13, 1993
8.1.4 A door or cover that provides access to a live part, film-coated wire, or moving part, that may result
in a risk of electric shock, shall be securely held in place so that it can be opened or removed only by
using a tool.
8.1.4 effective April 13, 1993
8.2 User servicing
8.2.1 Live parts, film-coated wire, and moving parts shall be arranged and covers located so as to reduce
the likelihood of a risk of electric shock while covers are being removed and replaced if it is necessary to
do so to perform a servicing function as indicated in the operator’s instruction manual accompanying the
converter or inverter.
8.2.1 effective April 13, 1993
8.2.2 Live parts, film-coated wire, and moving parts shall be:
a) Recessed at least 1/8 inch (3.2 mm) from the plane of the front of the fixed portion of an
enclosure; or
b) Recessed at least 1/8 inch (3.2 mm) from the front edge of a wiring compartment, in the case
of a device mounted to the face of a wiring compartment; or
c) Afforded equivalent protection by projections or guards.
To determine whether such live parts, film-coated wire, and moving parts comply with the requirement in
8.2.1, the cover is to be removed and replaced. Contact of either persons or a conductive cover with live
parts, film-coated wire, or moving parts is unacceptable.
8.2.2 effective April 13, 1993
8.2.3 Operations and adjustments that are considered to subject parts to contact by the user include
those made at the time of installation or during normal use, and operations such as relamping, replacing
a fuse, and resetting an overload device.
8.2.4 A part on the back of a component mounting panel and a part located so as to require major
disassembly by using a tool are not considered to be exposed to the user, and are not considered to be
exposed to the serviceman unless it is likely that servicing will be done while the parts are energized after
disassembly.
DECEMBER 14, 1993 UL 458 19
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