Mitsubishi Heavy Industries SRK20MA-S User Manual

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Serial signal transmission error (Wrong power supply and signal cable connection, failure of
indoor and outdoor PCB, error of power supply system)
Indoor fan motor error (Failure of fan motor, failure of indoor PCB)
Compressor lock (Failure of compressor, failure of outdoor PCB)
No
Is the power supply abnormal in
operation after reset?
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Failure caused by one-time reason (noise,
etc.), not failure of machine
Is the indoor and outdoor
connection correct?
Correct the indoor and outdoor connection
Dose the voltage between indoor
terminal block 2~3 fluctuate
between DC 0V and about 12V?
Failure of indoor PCB
Check the connection
Dose the voltage between outdoor
terminal block 2~3 fluctuate
between DC 0V and about 12V?
Is there AC voltage of
220/230/240V between outdoor
terminal block 1~2?
Failure of indoor PCB. Check the
connection.
Is the power supply system
(protective tube, choke, etc.) in
good condition?
Replace the protective tube, choke, etc.
Failure of outdoor PCB
No
No
Yes
Yes
Is the connection of the connector
normal?
Correct the connector.
Has voltage been applied to the fan
motor?
Failure of indoor PCB
Failure of fan motor
No
Yes
Has all three-phase output
voltage been applied to the power
transistor?
Failure of inverter
Check the compressor.
Visually inspect wiring of compressor
Check insulating resistor (above 1MΩ)
Check winding coil resistor (about several Ω)
In normal cases, the
compressor is locked.

Mitsubishi Heavy Industries SRK20MA-S Specifications

General

Brand	Mitsubishi Heavy Industries
Model	SRK20MA-S
Category	Air Conditioner
Language	English