Daikin REYQ72 Serveice Manual page 224

SiUS39-602
Check No. 12 Check on pulse input of position signal of fan inverter PCB
(1) Disconnect the connector X2A while power supply OFF and operation OFF.
(2) Is the voltage between pins No. 4 and 5 on X2A approx. 15 V after power supply is turned on?
(3) Connect the connector X2A while power supply OFF and operation OFF.
(4) Check below conditions when the fan motor is rotated one turn manually under the condition
The condition (2) dose not appear → Faulty PCB → Replacing the PCB
The conditions (4) do not appear → Faulty hall IC → Replacing fan motor of outdoor unit
Check No. 13 Power transistor check mode
When the inverter system malfunctions (malfunction of inverter, INV compressor), to locate
where the malfunction occurs, switching to the power transistor check mode of inverter in the
service mode setting enables not to judge the position detection signal malfunction but to output
waveform only during inverter operation. (The waveform can be checked by disconnecting the
wiring of compressor.)
After the completion of checks, return the system to the previous mode and wait for 30 seconds
or more until the discharge of capacitor is completed. Then, conduct a subsequent work.
Note: Be sure to disconnect the compressor wiring when conducting the check operation mentioned above.
When the output voltage is approx. 100~200 V (10 Hz) and the voltage balance between
phases U-V, V-W, W-U is within ±5%, the inverter PCB is normal.
* Voltage output will be different depend on measuring device.
Troubleshooting
of operation OFF after power supply is turned ON.
Are the pulse (approx. 0 V and 5 V) generated 4 times between No. 1 and 5 on X2A?
Are the pulse (approx. 0 V and 5 V) generated 4 times between No. 2 and 5 on X2A?
Are the pulse (approx. 0 V and 5 V) generated 4 times between No. 3 and 5 on X2A?
Troubleshooting (OP: Unified ON/OFF Controller)
5 Gray GND
4 Pink Vcc (approx. 15 V)
3 Orange Position signal W
2 Blue Position signal V
1 Yellow Position signal U
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