Wiring Diagram - Noritz NR501-OD Service Manual

6. Wiring Diagram

<NR501-OD, NR662-OD>
WIRING DIAGRAM
Circuit Board Block Diagram
HOT
FREEZE PREVENTION
HEATER
DC170V
DC12V
DC15V
15V POWER CIRCUIT
GND
HIGH LIMIT
SWITCH
COLOR CODING
W
VARISTOR
RELAY 1
DC170V
POWER
COMBUSTION FAN
CONTROLLER
RELAY 2
PRIMARY
WATER FLOW SENSOR
C A
SECONDARY
WATER SERVO - MAIN
B
RELAY 1
GAS PROPORTIONING VALVE
POWER CONTROL CIRCUIT
RELAY 2
FLAME DETECTING CIRCUIT
FLUSH CONNECTOR
THERMAL FUSE
SOLENOID VALVE 0
GAS SOLENOID VALVE
DRIVING CIRCUIT
SOLENOID VALVE 1
SOLENOID VALVE 2
SOLENOID VALVE 3
: White BK : Black BR : Brown
: Gray
R : Red GY V : Violet
NEUTRAL
10A(FUSE)
FAN CONTROL
OUTPUT
VARISTOR
FAN ROTATION
VARISTOR ARRESTER
SPEED INPUT
EARTH
FAN CURRENT
VALUE INPUT
IGNITER E
IG
GND
D
FLAME ROD EARTH
5V POWER CIRCUIT
25
O
Y : Yellow
G
BL : Blue
Minimum Manifold Pressure Set Button
FAN
A
PULSE
CONTROL
B
CIRCUIT
C
D
Sub-CPU
E
SUB
CONTROL
UNIT
THERMISTOR
- AIR
THERMISTOR
- HOT WATER
THERMISTOR
- COLD WATER
THERMISTOR
- HEAT EXCHANGER
GND