Over Heat Of Compressor; Error Of Signal Transmission - Mitsubishi Heavy Industries SRK20ZG-S Tech Manual

Over heat of compressor

Is discharge pipe sensor
resistance value good?
Is sufficient quantity of refrigerant
circulated?

Error of signal transmission

Does error persist after power
reset?
Are the lines connecting the indoor
and outdoor units connected
normally?
Is DC 0~Approx. 12V detected
between 2~3 terminals on
indoor unit terminal block?
Is DC 0~Approx. 12V detected
between2~3 terminals on
outdoor unit terminal block?
Is AC 220/230/240V applied
between 1~2 on the outdoor side
terminal block?
(page 43)
YES
YES
Defective outdoor unit PCB
YES
YES
YES
YES
YES
Defective outdoor unit PCB
Connector connection check, resistance
NO
value check, replacement of discharge pipe
sensor
NO
Does trouble persist after
charging gas?
YES
Clogged capillary tube or
strainer, defective EEV, etc.
[Wiring error including power cable, defective indoor/
outdoor unit PCB]
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.
45
- -
[Gas shortage, defective discharge
pipe sensor]
NO Check if there are any
places where gas is leaking.