Circuit Board Checkpoints - Noritz NR501-OD Service Manual

<NR501-OD, NR662-OD>

Circuit Board Checkpoints

Ref.
Part
No.
Overheat Prevention
1
Device (Thermal Fuse)
2 Water Servo-Main
3 Water Flow Sensor
4 Thermistor-Cold Water
5 Thermistor-Hot Water
Thermistor-Heat Exchanger
6
7 Thermistor - Air
8 Flame Rod
9 Flame Rod
10 Fan Motor
11
Igniter
12
Primary Gas
Solenoid Valve
14 Gas Solenoid Valve - 1
15 Gas Solenoid Valve - 2
16 Gas Solenoid Valve - 3
Gas Proportioning Valve
17
High Limit Switch
Power Supply
-
(Power Circuit Board)
Power Supply
-
(Power Circuit Board)
Display Window
-
- Remote Controller
Note 4) •Cold Water / Hot water / Heat Exchanger Thermistor Temperature Characteristics
Temperature (° F)
32
Temperature (° C)
0
Resistance (k Ω)
23.7
Note 5) •Thermistor - Air Temperature Characteristics
Temperature (° F)
-4
Temperature (° C)
-20
Resistance (k Ω)
106.5
Circuit board Check points
(Check the wiring diagram
behind the front cover)
CN & Pin No. No. CN & Pin
CN10 15 BL - W CN10
1 W - O
1 W - G
CN59
CN59 1 W - V
1 W - BK
2 Y - BL
CN63
CN104 4 R - BL
10 R - BL
CN63 CN63
9 Y - BL
CN63 4 CN63
W - BK
CN63 1 W - BK CN63
CN63 3 W - BK CN63
CN63 5 BK - BK CN63
BL -
1
Burnercase
CN78
BL -
1
Electrode
BL -
1
Burnercase
CN78
BL -
1
Electrode
CN27 4 BR - BL CN27
1 R - BL
CN27 CN27
3 Y - BL
CN42 6 BK - BL/W CN102
CN10 10 W - BL CN10
CN10 8 BK - BL CN10
CN10 7 GY- BL CN10
CN10 6 O - BL CN10
CN10 4 R - BL CN10
CN10 13 W - W CN10
CN92 3 W - BK
CN102 2 R - BL/W CN102
CN142 R - BL CN142
Note 6) Note 6)
BL - BL
Terminal
CN89A CN89B
-Terminal
50 68 86 104
10 20 30 40
15.5 10.3 7.0 4.9
14 32 50 68
-10 0 10 20
59.6 34.4 20.6 12.6
Normal value
No.
13 2Ω or less
3 DC 1 - 16 V
4 DC 1 - 16 V
5 DC 1 - 16 V
6 DC 1 - 16 V
12 DC 1V or less
12 DC 14V - 16 V
12 DC 14V - 16 V
DC 0.5 - 15 V
over 408 pulses/min.
12
(over 6.8Hz)
DC 1 - 4.5 V
2
2 DC 1 - 4.5 V
2 DC 1 - 4.5 V
DC 0.7 - 4.4 V
10 kHz - 100 kHz
GND
-
Flame DC 0.45μA or less
Rod
10 kHz - 100 kHz
GND
-
Flame DC 1μA or more
Rod
2 DC 7 - 45 V
2 DC 10 - 14 V
2 100 Hz - 400 Hz
3 DC 14 - 16 V
DC 1 - 16 V
11
20 - 35 Ω
DC 1 - 16 V
11
35 - 65 Ω
DC 1 - 16 V
11
35 - 65 Ω
DC 1 - 16 V
11
35 - 65 Ω
DC 0.3 - 15 V
3
50 - 80 Ω
5 1Ω or less
CN92 4 AC 108 - 132 V
3 DC 14 - 16 V
2 DC 14 - 16 V
4 1Ω or less
- DC 14 - 16 V
122 140 158 176
50 60 70 80
3.5 2.5 1.9 1.4
Note 6) Between CN142 No.4 of both Main circuit board
86
and Display window circuit board
30
8.0
29
When valve is fully open
Y(+) BL(-)
32 - 212° F
Note 4)
0 -100° C
32 - 212° F
Note 4)
0 -100° C
32 - 212° F
Note 4)
0 -100° C
Note 5)
When no flame is detected
4 pulse/revolution
When igniter is sparking
When valve is open
Coil resistance
When valve is open
Coil resistance
When valve is open
Coil resistance
When valve is open
Coil resistance
Coil resistance
Contact resistance