Compressor Lock - Mitsubishi Heavy Industries SRK25GZ-L1 Handbook

Outdoor fan motor error
Is connector connection good?
Is voltage applied to fan motor?
Serial signal transmission abnormality
Is this a recurring error when reset-
ting power supply?
Is the wiring connection between the
indoor and outdoor unit improperly wired?
Does the voltage between terminals 2
and 3 on the indoor unit oscillate bet-
ween approximately DC 0 and 12 volts?
Does the voltage between terminals 2
and 3 on the outdoor unit oscillate bet-
ween approximately DC 0 and 12 volts?
Is AC 220/240 V measured between ter-
minals 1 and 2 on the outdoor unit?
Is the electrical system operating
properly (fuse, reactor, etc.)?
Defective outdoor cir-
cuit board

Compressor lock

Is output voltage applied to all 3
phases of power transistor?
NO
YES
NO
(DC)
YES
Defective fan motor
NO
YES
(1)
NO
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
YES
¡ Check compressor wiring visually.
Inspect compressor.
¡ Check insulation resistance. (1 MΩ or over)
¡ Check coil wire resistance. (Few Ω)
Correct connector
connection.
Defective outdoor unit
PCB
[Indoor/outdoor printed circuit board defect
Outdoor power source abnormality]
Possible causes include interference
This is due to a tempo-
from the lighting, spontaneous load inter-
rary cause (interfer-
ference, power supply interference and
ence, etc.) and is not
radial interference.
a failure of the unit.
Correct indoor and out-
door unit connections.
Defective indoor unit
circuit board.
Inspect interconnec-
tion wire.
Defective indoor unit
circuit board. Inspect
interconnection wire.
Replace fuse and reac-
tor.
[Defective compressor, defective
outdoor PCB]
Defective inverter
SCM-HG (2 room)
[Defective fan motor,
defective outdoor PCB]
If check results are normal,
compressor is locked.
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