Mitsubishi Electric PUHY-P168, Service Handbook

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[
IX
Troubleshooting ]
Note1 For the connectors on the board, TH11 and TH12 are connected to CN10, and TH15 and TH16 are connected to
CN11. Disconnect the connector in trouble, and check the sensor of each number.
Note 2, 3
1) Pull out the sensor connector from the I/O board
Do not pull the sensor by holding the lead wire.
2) Measure the resistance with such as a tester.
3) Compare the measured value with that of shown in the figure below. When the result is +-10%, it is normal.
Note4 Check the self-diagnosis switch (Outdoor control board SW1).
1 2 3 4 5 6 7 8 9 10
ON
1 2 3 4 5 6 7 8 9 10
ON
1 2 3 4 5 6 7 8 9 10
ON
1 2 3 4 5 6 7 8 9 10
ON
1 2 3 4 5 6 7 8 9 10
ON
1 2 3 4 5 6 7 8 9 10
ON
1 2 3 4 5 6 7 8 9 10
ON
1 2 3 4 5 6 7 8 9 10
ON
TH22
TH25
TH22
TH25
Liquid inlet temperature
Bypass outlet temperature
Bypass outlet temperature
Bypass outlet temperature
TH11
TH12
Bypass inlet temperature
Bypass inlet temperature
Bypass inlet temperature
Bypass inlet temperature
TH15
TH16
Measurement data SW1 setting value Symbol
NU-G GA
(Standard / main)
NU-GB
(Sub 1)
NU-GB
(Sub 2)