MIL-HDBK-1025/10
Cutting of Underground Cables
8.6.5
WARNING
All cable to be cut should be positively identified and de-energized before
each cut. Before making an opening in or removing a part of the sheath
or sleeve of a cable, the line will be grounded at the first possible
grounding point on each side of the work location. Perform all medium
and high voltage cable cutting remotely from topside using a guillotine
cutter and permit no workers to remain in the space during the cutting.
This will isolate workers by a safe distance in the event of an accidental
arc-blast when the cut is made. If guillotine cutting is not feasible due to
cable configuration, location, or other complications, hand-cutting may be
required.
a. Always wear rubber gloves when sawing into a cable or removing the sheathing.
Install a metallic jumper between two sides of the location where a cable sheath is to be removed
or cut.
b. When a medium-voltage cable is to be cut, a short section of the shielding, if any, will
be removed completely from around the cable. Tests will be made with two statiscopes or other
approved testing devices, to determine whether or not the cable is de-energized. If no indication
of a live cable is obtained, the worker may proceed with the work.
c. When opening a splice in a medium-voltage cable, the sleeve over the splice will be cut
completely around near the splice and then cut lengthwise and removed. No effort will be made
to remove the compound. Workers will then test over each side of the conductor with two
statiscopes or other approved testing devices. If no indication of a live cable is obtained, the
compound will be removed. If shielding tape is then encountered, it will be removed and another
test made over each side of the conductor with two statiscopes or other approved testing devices.
If no indication of a live cable is then obtained, the splice will be cut through until the saw touches
one of the conductors. Before sawing further a statiscope test will be made on the blade of the
saw.
d. When cutting or opening splices on low-voltage cables, the same procedure as outlined
above for medium-voltage cables will be followed, except in testing. To determine whether the
cable is energized the insulation will be cut away to the conductor and tested with an approved
tester. On multiple-conductor cables, only one conductor will be cut into a time and tests made
on at least two conductors before proceeding with the work.
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