TM 5-4520-241-14
KEY TO DIAGRAM
B1
Ventilating motor
B2
Combustion motor
C1
Capacitor, interference
suppression
C2
Capacitor, interference
suppression
CB1
Circuit breaker, 20 amps
CR1
Rectifier (Fuel pump
power supply)
CR2
Rectifier (Time delay)
DS1
Incandescent lamp (Red)
DS2
Incandescent lamp (White)
E1
HR1
Fuel heater
HR2
Bimetal heater/sensor
(Time delay)
J1
POWER RECEPTACLE
J3
ROOM THERMO receptacle
J3
Female receptacle
J4
EXTERNAL FUEL PUMP
RECEPTACLE
L1
Solenoid valve
PC1
PC board assembly
P1
Male plug (Control box)
Q1
Transistor
S1
Switch, SPST (RESET)
S2
Toggle switch
(HEATER-OFF-FAN)
S3
Flame switch
S4
Thermal cutout switch
S5
Overheat thermostat switch
S6
Overheat thermostat switch
S7
Fuel thermostat switch
S8
Safety switch
TB1
Terminal board
(Terminal strip)
T1
Ignition transformer
T2
Fuel pump power
supply transformer
T3
Time delay transformer
Figure 1-4. Wiring diagram.
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