Daikin RXYQ72 Serivce Manual page 226

SiUS39-601
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 of
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.
Notes: 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
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?
step 1 :
mode 2
code 28
Magn.sw.
set 01→02
K1M on
Magn.sw.
K1M off
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
Voltage
output
Frequency
U-V-W
= 10 Hz
–100
~200
VAC
–3 sec
–6 sec
Voltage
output
U-V-W
Frequency = 240 Hz
–100
~200
VAC
set 02→01
–50 VAC
–30 sec
step 2 :
mode 2
code 28
215