TM 9-2320-272-10
1-19.
ELECTRICAL SYSTEMS OPERATION (Contd)
f.
Heating System Operation.
The electrical portion of the heating system is identical for all models covered in the manual and consists of
the following major components and circuitry:
G
PROTECTIVE CONTROL BOX - Provides 24-volt power to circuit breaker through circuits 5 and 5a and to
the heater switch through circuits 27 and 5c.
H
CIRCUIT BREAKER - Provides overload protection for 24-volt circuits 5, 5a, 27, and 5c leading to the heater
switch.
I
BATTERY SWITCH - Provides 12-volt battery power from circuit 569 through 569A to the heater.
J
CIRCUIT BREAKER - Provides overload protection for 12-volt circuit 569A leading to heater switch.
K
HEATER SWITCH - Controls low and high blower motor speed and has two sources of power; 12-volt power
is supplied through circuit 569A from the battery switch and is used to provide low speed; 24-volt power is
supplied through circuit 5C from the protective control box and is used to provide high speed.
L
HEATER BLOWER MOTOR - A direct current motor controlled by the heater switch through circuit 400.
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