TM 1-1500-204-23-4
(6)
Suitable mechanical guards, such as
enclosures or barricades, shall be permanently installed
on all machinery not already equipped with such to
eliminate danger of injury from moving parts.
(7)
Machinery shall not be adjusted, repaired,
oiled, or cleaned while machine is in operation or power
is on.
(8)
Personnel operating machinery shall wear
protective clothing as prescribed. A protective face
shield or goggles shall be worn when operating a grinder
regardless of whether grinder is equipped with attached
shields.
(9)
Jewelry
shall
not
be
worn
while
performing any maintenance.
d.
Fire Safety. A constant vigilance must be
maintained to seek out fire hazards. Fire hazards are
constantly present in the shop where sparks, friction, or
careless handling can cause an explosion that may
destroy equipment or buildings, and injure or kill
personnel. Refer to AR 385-10, The Army Safety
Program and The Occupational Safety and Health Act of
1971.
(1)
NO SMOKING signs shall be placed in
areas where smoking could create a fire hazard.
(2)
Personnel shall be trained in the use,
knowledge, and location of shop fire fighting equipment.
(3)
Each shop shall be equipped with fire
extinguishers suited for type fire most likely to occur.
(4)
Use correct fire extinguisher for class of
fire as follows:
·
Class A fire (wood, paper, trash, etc). Use water or
bromotrifluoromethane fire extinguisher.
·
Class B fire (oil, paint, fuel, grease, etc). Use
bromotrifluoromethane
or
carbon
dioxide
fire
extinguisher, or dry chemical extinguisher with class
B rating.
·
Class
C
fire
(electrical
equipment).
Use
bromotrifluoromethane
or
carbon
dioxide
fire
extinguisher, or dry chemical extinguisher with class
C rating.
·
Class D fire (combustible metals) magnesium,
titanium,
zirconium,
sodium,
lithium,
and
potassium). Use dry powder type fire extinguisher.
(5)
Oily waste, rags, and similar combustible
materials shall be discarded in self-closing metal
containers which shall be emptied daily.
(6)
Use only approved cleaning solvents.
(7)
Flammable materials shall not be stored
in the shop.
e.
Maintenance of Shop Equipment. Maintenance
of shop equipment consists of cleaning, preventive
maintenance, and replacement of defective parts.
Preventive
maintenance
includes
before-operation,
during-operation, after-operation, services performed by
operator, and scheduled services to be performed at
designated intervals. Consult the operation and service
instructions
manual
for
specific
maintenance
instructions on particular types of equipment.
2-2. Basic Principles and Theory for Direct Current.
Direct Current (dc) flows constantly in only one direction
with a constant polarity. It changes magnitude only
when the circuit is opened or dosed, as shown in the dc
wave form in figure 2-1.
2-3. Basic Principles and Theory for Alternating
Current. Alternating current (ac) flows periodically first
in one direction and then in the opposite direction, as
shown in figure 2-2. The time necessary for the current
to go from 0 to a maximum positive, to 0, to maximum
negative, and return again to 0 is the time for one cycle.
That portion of the cycle during which the current flows
in one direction only is called an alternation. Frequency
is the number of I cycles occurring per second, and an
alternating current may be any frequency.
2-4. Wiring Diagram Symbols, Charts, and
Schematics. See figures 2-3 and 2-4 for wiring
diagram symbols and schematics.
2-5. Basic Circuits. The basic electrical circuits of
series, parallel, and compound are explained in the
following paragraphs.
a.
Series. The series circuit, as shown in figure 2-
5, is the most basic type of electrical circuit. It provides
a complete path for current to flow from the negative to
Change 3
2-2
