High-Voltage Precautions
NEVER work alone near high-voltage equip-
ment. Don't use tools and equipment containing
metal parts within 4 feet of high-voltage circuits
or any wiring having exposed surfaces. The
handles of all metal tools, such as pliers and
cutters, should have rubber insulating tape covers.
You can't use plastic or cambric sleeving or
friction tape alone for this purpose when working
with circuits having a high potential voltage.
Before touching a capacitor, short-circuit the
terminals to discharge the capacitor completely.
Permanently attach grounded shorting prods to
workbenches where electrical devices receive
regular servicing.
Don't work on any type of electrical apparatus
with wet hands or while wearing wet clothing.
Don't wear loose or flapping clothing. Don't wear
thin-soled shoes with metal plates or hobnails;
wear safety shoes with nonconducting soles when
available. Don't wear flammable articles, such as
celluloid cap visors.
Before you work on an electrical or electronic
apparatus, remove all rings, wristwatches,
bracelets, and similar metal items. Make sure that
your clothes do not contain exposed zippers, metal
buttons, or any type of metal fastener.
Make sure warning signs and suitable guards
are posted to prevent personnel from coming into
accidental contact with high voltages.
Low-Voltage Precautions
Figure 2-1.-Radiation, intake, exhaust, and turbine blade
failure danger areas.
Most people never realize the dangers of
low-voltage electric shock. These hazards are
present and dangerous. You need to be aware of
PRECAUTIONS REGARDING
their existence; you should be aware of any
PERSONNEL AND MATERIALS
voltage greater than 15 volts.
If possible, you shouldn't make repairs on
DEGREE OF SHOCK. --The current that
energized circuits. When repairs on operating
may pass through the body without causing
equipment are necessary, only experienced person-
damage depends on the individual, and the type,
nel under the supervision of a senior AE should
path, and length of contact time. The resistance
do the work. Follow every known safety precau-
of your body varies. For example, if the skin is
tion carefully. Make sure there is enough light for
dry and unbroken, body resistance will be quite
good illumination, and there is insulation from
high--on the order of 300,000 to 500,000 ohms.
ground, using a suitable nonconducting material.
However, if the skin becomes moist or broken,
Station helpers near the main switch or the circuit
body resistance may drop to as low as 300 ohms;
breaker to de-energize the equipment immediately
a potential as low as 30 volts could cause a fatal
in case of emergency. While making the repair,
current flow. Therefore, any circuit with a higher
someone qualified in first aid should be standing
value potential is more dangerous. If a 60-hertz
by in case of injury due to electrical shock.
