Compressor Lock - Mitsubishi SCM45ZA User Manual

Outdoor fan motor error
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.)?

Compressor lock

228
Is connector connection good?
YES
Is voltage applied to fan motor?
(DC)
YES
Defective fan motor
YES
(1)
YES
YES
YES
YES
YES
Defective outdoor cir-
cuit board
Is output voltage applied to all 3
phases of power transistor?
YES
¡ Check compressor wiring visually.
Inspect compressor.
¡ Check insulation resistance. (1 MΩ or over)
¡ Check coil wire resistance. (Few Ω)
NO
Correct connector
connection.
NO
Defective outdoor unit
PCB
[Indoor/outdoor printed circuit board defect
Outdoor power source abnormality]
This is due to a tempo-
NO
rary cause (interfer-
ence, etc.) and is not
a failure of the unit.
NO
Correct indoor and out-
door unit connections.
NO
Defective indoor unit
circuit board.
NO
Inspect interconnec-
tion wire.
Defective indoor unit
NO
circuit board. Inspect
interconnection wire.
NO
Replace fuse and reac-
tor.
NO
Defective inverter
[Defective fan motor,
defective outdoor PCB]
Possible causes include interference
from the lighting, spontaneous load inter-
ference, power supply interference and
radial interference.
[Defective compressor, defective
outdoor PCB]
If check results are normal,
compressor is locked.