23. Energizing Ac Circuits
the BLOWER switch to ON.
Warning: To prevent asphyxiation, the
shelter must be ventilated at all times
Caution: Open the air vent cover (fig. 5)
when occupied.
and the exhaust blower vent cover on the
front of the shelter before operating the
Prepare the AN/MSC-31 for full opera-
blowers.
tion as follows:
a. Connect the AN/MSC-31 to the avail-
c. lntercommunication S t a t i o n LS-
(1) Insert the power cord connector
light .
plug into the INTERCOM power
b. Operate the MAIN circuit breaker
duct receptacle (fig. 11) and con-
switch on the power distribution panel
nect the ground lead to the ground
terminal provided adjacent to the
c. Operate t h e BLACKOUT BYPASS
receptacle.
switch (fig. 14) to ON. When blackout con-
(2) Insert the signal cord plug into the
ditions are required, operate the switch
INTERCOM signal duct jack below
to OFF.
the SB-22(*)/PT (fig. 11).
d. Operate circuit breaker switch No. 1
(3) Operate the OFF-SEND switch to
(LIGHTS) to ON.
5 (approximately midposition). The
e. operate the LIGHT 1 and LIGHT 2
glowlamp will light,
switches (fig. 14) to ON. Operate the draft-
(4) O p e r a t e the PRESS TO TALK
ing light switch (fig. 16) to ON as required.
switch and speak into the speaker-
f. Check to
see that the voltmeter (fig.
microphone on the front panel; re-
10) indicates 115 volts at+ 10.
lease the PRESS TO TALK switch
g. Check to
see that the "ammeter indi-
to receive.
cates nearly O ampere.
Note. The OFF-SEND switch does no
h. operate circuit breaker switches No.
have to be operated to receive a call.
2 through 6 to ON.
(5) Operate the RECEIVE control to
regulate the volume of an incoming
call.
Note. The LS-147(*)/FI may be moved
Note. Refer to the applicable technical manuals
to an operating position on the roadside
(appx I) for operating procedures of the
major com-
f u n c t i o n s of controls and instruments of shelter
power cord connector plug and the signal
components.
cord into the appropriate CONVENIENCE 4
r e c e p t a c l e and INTERCOM jack, respec-
Warning: To prevent asphyxiation, the
tively; connect the power cord ground lead.
shelter must be ventilated at all times when
occupied.
25. Operation Under Adverse Climatic Con-
ditions
a. Electric Heater (fig. 17). Insert the
power cord connector plug into the appro-
AN/MSC-31 can be operated in extremely
priate HEATER receptacle (fig. 13 and 14)
cold or hot climates. The shelter offers
and operate. the HEAT-OFF-FAN switch to
complete protection from the elements for
the desired position.
personnel and equipment; however, when
the entrance boxes are exposed to adverse
Note. If the HEAT-OFF-FAN switch is operated
conditions, the following precautions are
to HEAT, set the TEMPERATURE CONTROL to
the desired setting.
necessary:
a. Cold Climates. Extreme cold causes
b. Exhaust Blowers. Connect the power
the cables and wires to become hard,
cord connector plug into the appropriate