MIL-HDBK-1025/10
fuse to interrupt any fault condition that was not corrected at the time of the fuse
replacement.
6.6.3 Open Fuse Holder. Do not leave outdoor fuse holders open for an
extended period of time, as water damage or warpage from the elements may make
closing them dangerous or degrade their protective ability.
6.6.4 Closed-Position Fuse Locking. Follow the fuse and/or switch
manufacturer's instructions, as appropriate, to be sure that the fuse is securely locked,
latched, and held fast in a closed position.
6.6.5 Bypassing. Do not bridge fuses or fuse cutouts internally. Where it is
necessary to bypass fused conductors, use plainly visible external jumpers and remove
them as soon as possible.
Energy-Storing Protective Device Safety
6.7
CAUTION
Protective devices such as surge arresters, choke coils, and
capacitors store electrical charges as a byproduct of their
protective mechanism. This stored charge should be discharged
to ground before such devices are to be considered de-energized.
Always wear eye protection when de-energizing or energizing
these devices.
6.7.1 Surge Arresters. A surge arrester limits overvoltages and bypasses the
related current surge to a ground system that absorbs most of the energy. The
overvoltage condition can be caused by a fault in the electrical system, a lightning strike,
or a surge voltage caused by switching loads. All surge arrester equipment should be
considered as loaded to full circuit potential, unless it is positively disconnected from the
circuit. Be sure the permanent ground conductor is intact before any work is done.
6.7.1.1 Surge Arrester Contact. Substations with grade level surge arresters
should always be provided with screens or fences to prevent possible contact while parts
of the surge arresters may be alive. The screen or fence should have a gate large enough
to permit the removal of individual units. The gate should be provided with a lock and the
key should be kept by an authorized person. Surge arresters should never be touched,
unless they are completely disconnected from all live lines and live equipment and until all
parts have been discharged to ground and effectively grounded.
6.7.1.2 Disconnecting Surge Arresters. Horn gap switches should be fully
opened and completely separated from all live lines and equipment, whenever it is
necessary to work near a surge arrester. If the first attempt to disconnect a surge arrester
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