Circuit Board Checkpoints - Noritz NR50-OD Service Manual

<NR50-OD / NR66 (-SV,-OD) / N-0531S (-OD), NR71 (-SV,-OD) / N-0631S (-OD)>

Circuit Board Checkpoints

Ref Circuit Board Checkpoints
Part
No.
CN & Pin No.
1
Thermal Fuse
CN59
2 Water Flow Sensor
CN59
3
Inlet Thermistor
CN59
4
Outlet Thermistor
CN78
5
Flame Rod
Fan Motor
6
CN27
7
Fan Motor
8
Igniter CN1
Primary Gas
9
Solenoid Valve
CN10
Gas Solenoid
10
Valve 1
Gas Proportioning
11
CN59
Valve
CN78
12 Flame Rod
13 High Limit Switch
CN1
Gas Solenoid
14
CN10
Valve 2
15
Water Control Valve
CN86
—
Power Supply CN92
—
Remote Controller
Te rminal
Note 1) Temperature characteristic of inlet / outlet thermistor
Temperature ( ˚ F)
32 50
Temperature ( ˚C )
0 10
Resistance (kΩ)
23.7 15.5
Harness
CN & Pin No.
Color
1 BL-R CN59 4 2Ω or less
4 R-BL 6 DC14 – 16V
CN59 DC0.5 – 15V
5 Y-BL 6
more than 1440 pulse/min. (more than 24Hz)
13 W-W 14 DC0.6 – 4V
CN59
14 DC0.6 – 4V
15 W-W
BL-
1 – 75kHz – 92kHz
—
Burnercase
DC0.45 μA or less
BL-
1 –
Electrode
4 BR-BL 2 DC0 – 43V
1 R-BL 2 DC11 – 13V
CN27
7200 – 23200pulses/min.
3 Y-BL 2
(120Hz – 387Hz)
2 BK-W CN1 4 AC90 – 110V
DC80 – 100V
4 W-BL 6
1.0 – 2.0kΩ
CN10
DC80 – 100V
1 BK-BL 6
1.0 – 2.0kΩ
DC0.3 – 15V
4 R-BL CN59 3
50 – 90 Ω
BL-
1 – 75kHz – 92kHz
Burnercase
—
DC1 μA or more
BL-
1 –
Electrode
3 less than 1Ω
1 W-W CN1
DC80 – 100V
2 GY-BL CN10 6
1.0 – 2.0kΩ
8 R-BL 1 DC14 –16V
2 Y-BL 1 DC1V or less
3 5
W-G DC1 –16V
CN86
3 7
W-V DC1 –16V
3 4
DC1 –16V
W-O
3 6
DC1 –16V
W-BK
1 W-BK 2 AC90 – 110V
CN92
– — —
– DC13 – 16V
68 86 104 122
20 30 40 50
10.3 7.0 4.9 3.5
Normal Value
Remarks 1
YI (+)
32°F – 212°F
32°F – 212°F
When no flame is detected
When igniter is sparking
Measure coil resistance
Measure coil resistance
Measure coil resistance
At flame detection
Measure contact resistance
Measure coil resistance
When valve is fully open.
(ON/OFF switch OFF)
140 158 176
60 70 80
2.5 1.9 1.4
57
Remarks 2
BI (–)
Note 1)
Note 1)