6 December 2006
Including change 1, 7 December 2006
Fuses might fail during handling if energized, creating arc flash hazards.
Wear arc rated clothing or switching suits when changing energized fuses
in accordance with Chapter 4 requirements.
Characteristics. A fuse is a single-phase device. Fuses can be subject to
partial melting or damage by currents that might not have been of sufficient magnitude
to blow the fuse.
Fuse Handling. Fuses must normally not be handled, except when they
need to be replaced. Pull them briskly, and remove completely. Use safety glasses
and face shields when replacing fuses in primary fuse cutouts, do not use your free arm
in an attempt to shield your eyes from possible flashes. The worker changing the fuses
must stand firmly on a level surface. Where operating in an elevated position, the
worker will be secured with a safety lanyard/harness to prevent a slip and fall if there is
a flash. Fuse sticks must be used in all instances. Whenever possible, deenergize the
circuit before removing a fuse.
Operation of Energized Fuses. Open all lines protected with energized
fuses in the same manner as for air switches. Deenergize non-load-break type
installations. For load-break installations, wait for a short time after fuse replacement in
order to allow the fuse to interrupt any fault condition that might remain prior to the fuse
Open Fuse Holder. Do not leave outdoor fuse holders open for an extended
period of time. Water damage/moisture or warping could make closing them
dangerous, or degrade their protective ability.
Closed-Position Fuse Locking. Follow the fuse or switch manufacturer's
instructions, as appropriate, to be sure that the fuse is securely locked, latched, and
held fast in a closed position.
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.