Daikin REYQ72 Serveice Manual page 120

SiUS39-602
3.2.8 Power Transistor Check Operation
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.
Refer the detail power transistor check to page 213.
Test Operation
Field Setting
109