electric cables; however, do this only in an emergency
The following safety practices will help you avoid
receiving an electric shock
situation.
Keep your clothing, hands, and feet dry if
Do not wear a wristwatch, rings, other metal
possible.
objects, or loose clothing that could become
caught in live circuits or metal parts.
When you work in a wet or damp location, use a
dry, wooden platform to sit or stand on.
Wear dry shoes and clothing, and ALWAYS wear
Place rubber matting or other nonconductive
a face shield.
material between you and the wood surface.
Tighten the connections of removable test leads
When you work on exposed electrical
on portable meters. When checking live circuits,
equipment, use insulated tools and a nonmetallic
NEVER allow the adjacent end of an energized
flashlight.
test lead to become unplugged from the meter.
Ensure a person qualified to give
LIVE CIRCUITS
mouth-to-mouth resuscitation and cardiac
The safest practice to follow when you maintain or
massage for electric shock is in the immediate
repair electrical and electronic equipment is to
area.
de-energized all power supplies. However, there are
Ensure a person who is knowledgeable of the
times when you can't do this because de-energizing the
circuits isn't desirable or possible. For example, in an
system is standing by to de-energize the
emergency (damage control) condition or when
equipment.
de-energizing one or more circuits would seriously
Tie a rope around the worker's waist to pull him
affect the operating of vital equipment or jeopardize the
or her free if he or she comes in contact with a
safety of personnel, circuits aren't de-energized. No
live circuit.
work may be done on energized circuits before
obtaining the approval of the commanding officer.
Work with one hand only; wear a rubber glove
When working on live or hot circuits, you must be
on the other hand. (Where work permits, wear
supervised and aware of the danger involved. The
gloves on both hands.)
precautions you must take to insulate yourself from
ground and to ensure your safety include the following
actions:
LEAKAGE CURRENTS
Provide insulating barriers between the work and
the live metal parts.
The ungrounded electrical distribution system used
aboard ship differs from the grounded system used in
Provide ample lighting in the immediate area.
shore installations. Never touch one conductor of the
Cover the surrounding grounded metal with a dry
ungrounded shipboard system, because each
insulating material, such as wood, rubber
conductor and the electrical equipment connected to
matting, canvas, or phenolic. his material must
it have an effective capacitance to ground. If you
be dry, free of holes and imbedded metal, and
touch the conductor, you will be the electrical current
large enough to give you enough working room.
path between the conductor and the ship's hull. The
Coat metallic hand tools with plastisol or cover
higher the capacitance, the greater the current flow will
them with two layers of rubber or vinyl plastic
be for your fixed body resistance. This situation occurs
tape, half-lapped. Insulate the tool handle and
when one conductor of the ungrounded system is
other exposed parts as practical.
touched while your body is in contact with the ship's
NOTE: Refer to Naval Ships' Technical
hull or other metal enclosures. If your hands are wet or
Manual, chapter 631, for instructions on the use of
sweaty, your body resistance is low. When your body
plastisol. If you don't have enough time to apply
resistance is low, the inherent capacitance is enough to
plastisol or tape, cover the tool handles and their
cause a FATAL electrical current to pass through your
exposed parts with cambric sleeving, synthetic resin
body.
flexible tubing, or suitable insulation from scraps of
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