Some examples of shock current levels and
durations that could cause fibrillation are:
21 milliamperes for 30 seconds,
44 milliamperes for 7 seconds, or
67 milliamperes for 3 seconds.
HOW TO AVOID BEING SHOCKED
Preventing yourself from receiving an electric
shock can be summed up in three words: isolate,
insulate, and ground.
1. Isolate:
Isolate yourself from the source of
electric shock. Secure the power to equipment
before you attempt to work on it. Be sure to keep
all electrical equipment covers, doors, and
enclosures in place when you are not actually
working on the equipment. If you must leave
circuitry exposed, rope off the area, post
appropriate signs, and warn your fellow workers
of the danger.
2. Insulate: Make sure that the electrical tools and
equipment you use are properly insulated. Use
only approved insulated hand and portable
electric power tools. Check power and extension
cords frequently for deterioration, cracks, or
breaks. Breaks in the insulation cause many
electrical mishaps.
3. Ground: Electric current always follows the
path of least resistance. To prevent yourself
from being the unintentional path to ground,
make sure that your equipment is well
grounded. Well-grounded equipment will direct
any stray electric current to ground, thereby
protecting you from electric shock. A good
ground can also help protect your equipment
from excessive voltage spikes or lightning. For
further information on equipment grounding,
see Shipboard Bonding, Grounding, and Other
Techniques for Electromagnetic Compatibility
and Safety, MIL-STD 1310 (NAVY).
HOW TO TREAT VICTIMS OF ELECTRIC
SHOCK
The rescue of electric shock victims depends on
prompt action. However, to avoid becoming a victim
yourself, you must observe the following safety
precautions:
1. Shut off the voltage at once.
2. If you cannot shut off the voltage immediately,
try to free the victim from the live conductor by
using a dry board, belt, or clothing, or other
nonconducting material. Do not make direct
contact with any part of the victim’s body
with any part of your body! If you do, you
will become part of the same circuit and may
become an electric shock victim yourself!
3. After you remove the victim from the power
source, determine if he or she is breathing. If the
victim is not breathing, apply cardiopulmonary
resuscitation (CPR) without delay. Loosen the
clothing about the victim’s neck, chest, and
abdomen so that breathing is easier. Once the
victim is breathing, protect him or her from
exposure to cold, with a warm cover, if possible.
4. Keep the victim from moving. After a strong
shock, the heart is very weak. Any sudden effort
or activity may result in heart failure.
5. Send for a doctor or a corpsman, and stay with
the victim until medical help has arrived. Do not
give the victim stimulants.
To be able to successfully rescue a shock victim, it
is extremely important that you and your shipmates be
qualified in CPR. The effects of electric shock can
range from mild surprise to death. It depends on the
amount of current, the voltage, and the duration of the
electric shock. Since people have varying resistance
levels, it is hard to know exactly how a shock victim
will be affected. More than likely, the victim will be
very pale or bluish in color and may be unconscious.
Therefore, immediate action is of the utmost
importance.
Q1. What three key factors will determine the severity
of electric shock on your body?
Q2. What three one-word commands should you
follow to prevent shocking yourself?
VOLTAGE MEASUREMENT
You will be required to work on energized
equipment during many of your job assignments. For
example, as you troubleshoot a piece of electronic
equipment, the technical manual may instruct you to
measure voltages or to check signal waveforms while
the equipment is energized. If so, before you connect
the multimeter or the oscilloscope, there are certain
safety precautions and procedures you MUST follow
that are designed to protect you from electric shock.
These precautions and procedures are divided into two
3-3
