Mitsubishi Heavy Industries SRK25GZ-L1 Handbook page 44

SRK-GZ
Serial signal transmission error
Indoor fan motor error
Rotor lock
42
Does error persist after power
reset?
YES
Is there any wrong connection on
indoor/outdoor unit wiring?
YES
Is DC 0~Approx. 12V detected
between 2~3 terminals on
indoor unit terminal block?
YES
Is DC 0~Approx. 12V detected
between2~3 terminals on
outdoor unit terminal block?
YES
Is AC 220/240V applied between
1~2 on the outdoor side terminal
block?
YES
Is there any problem on the power
supply line (fuse, reactor,
capacitor, etc.)?
YES
Defective outdoor unit PCB
Is connector connection good?
YES
Is voltage (110~220V) applied to
fan motor? (Between White - Red)
YES
Defective fan motor
Is output voltage applied to all 3
phases of power transistor?
YES
Inspect compressor.
[Wiring error including power cable, defective indoor/
outdoor unit PCB, error on power supply system]
NO
Trouble by transient cause, not unit trouble.
NO
Correct improper wire connection on indoor/
outdoor unit.
NO
Defective indoor unit PCB
NO
Check crossover wires.
NO
Defective indoor unit PCB. Check crossover wires.
NO
Replace fuse, reactor or capacitor.
NO
Correct connector
connection.
NO
Defective indoor unit
PCB
NO
Defective inverter
¡ Check compressor wiring visually.
¡ Check insulation resistance. (1 MΩ or over)
¡ Check coil wire resistance. (Few Ω)
[Defective fan motor,
defective PCB]
[Compressor defect, outdoor
unit circuit defect]
If check results are normal,
compressor is locked.