THEORY
MSC-31 through IN POWER 115V
AC receptacle J1 in the power and
signal entrance box (para 17). Par-
a. SB-22(*)/PT Circuits. The external
allel-connected OUT POWER 115V
circuits for the SB-22(*)/PT connect to
AC receptacle J2 is provided so
the SIGNAL 1 26-pair cable receptacle
that another area assemblage may
in the power and signal entrance box (fig.
be connected to the AN/MSC-31
8) and to SIGNAL 1
binding post pairs in
power source.
the binding post signal entrance box (fig.
(2) Ac power from receptacle J1 is
9). The 21
binding post pairs (EIA
and B
applied through the power duct
through E21A and B) in the binding post
wiring to MAIN circuit breaker
signal entrance box are connected in par-
switch CB 7 on the power distribu-
allel with pins 1 (A and B) through 21 (A
tion panel.
C i r c u i t breaker
and B) of the 26-pair cable receptacle. In-
switches CB 1 through CB6 (par-
side the shelter, the SB-22(*)/PT circuits
allel-connected) are connected in
connect through signal duct wiring to the
series with CB7. Wiring to the
SB-22(*)/PT receptacle J2, and through
equipment and convenience recep-
the SB-22(*)/PT cable stub to the SB-
tacles is distributed through the
power duct from circuit breaker
switches CB 1 through CB6. Lamn
b. TA-312/PT Circuits. T h e external
DS7 is connected across the
circuits for the TA-312/PT's connect to
input lines to CB 7, and lights when
the PHONE 1 through 4 binding posts or to
power is applied to the AN/MSC-
pairs 22 through 25 of the 26-pair cable
31. Lamps DS1 through DS6 are
receptacle in the power and signal en-
connected across the circuits con-
trance box (fig. 8). Inside the shelter, the
trolled by CB1 through CB6, re-
TA-312/PT circuits connect through sig-
spectively, and light individually as
nal duct wiring to the PHONE 1 through 4
jacks (J1, J3, J4, and J7) in the signal
operated to ON.
A N / M S C - 3 1 is
b. Grounding. T h e
LS-147(*)/FI Circuit. The external
C.
circuit for the LS-147(*)/FI connects to
shock hazards. Ground terminals for the
the INTERCOM binding posts or to pair
AN/MSC-31 components are provided in-
26 of the 26-pair cable receptacle in the
side the S-183/MSC-31.
Inside the shelter, the LS-147(*)/FI cir-
Meter.
cuit connects through signal duct wiring to
the parallel-connected INTERCOM jacks
the ac input circuit after MAIN
(J2, J5, and J6) in the signal duct (fig. 11
circuit breaker switch CB7. It in-
and 12).
dicates the voltage applied from the
power source to the AN/MSC-31.
(2) Ammeter M2 is connected to the ac
input c i r c u i t through current
Note. The function of each switch and indicator
total current being draw by the
a. Ac Power Distribution.
operating components of the AN/
(1) Ac power is applied to the AN/
MSC-31.