Bradford White TG-199E-N - Manual (Page 30)

30
WARNING
DO NOT adjust any dipswitch settings on PC board unless instructed to do so.
RELAY 1 IG
FROST SENSING
SWITCH
ANTI-FROST HEATER
IGNITION
COMBUSTION
FAN
3A(FUSE)
HOT NEUTRAL
VARISTOR
DC12.6V
SOLENOID
DRIVING
CIRCUIT
CPU
CENTRAL
PROCESSING
UNIT
FAN
REMOTE
CONTROLLER
POV
FAN
CONTROL
CIRCUIT
BY-PASSFLOW
CONTROLDEVICE
CIRCUIT
THERMALFUSE
OVERHEAT
SWITCH
MODULATING
SOLENOID
VALVE
DC40V
DC5V
A B C SG
SWITCHING
POWER SUPPLY
THERMISTOR
CIRCUIT
B
SG
RELAY 1 A
WATERFLOW
SENSOR
CIRCUIT
WATERFLOW
CONTROL DEVICE
CIRCUIT
A
SG A
SG
SG
A
QS
SG
FR
FLAME
DETECTING
CIRCUIT
FLAME ROD
GND
SG
A
REMOTE
CONTROLLER
CIRCUIT
A B
E
PG
A B C
SG
SG
B
VARISTOR
ARRESTER
GND
SG
WATERFLOW
SENSOR
WATERFLOW
CONTROLDEVICE
BY-PASSFLOW
CONTROLDEVICE
M
M
DC12V DC170V
D
E
PG
SV3
SV2
SV1
SV0
RELAY
DRIVING
CIRCUIT
D
BY-PASS SERVOMODEL ONLY
OUTGOING WATER
THERMISTOR
HEAT EXCHANGER
THERMISTOR
AIR TEMPERATURE
THERMISTOR
INDOOR MODEL ONLY
MODULATING
VALVEPOWER
CONTROL
CIRCUIT
Figure 10. Ladder Diagram.