Check Of Outdoor Unit - Mitsubishi Electric MU-GA50VB Service Manual

9-4. Troubleshoot flow
Compressor and/or outdoor fan motor doesn't operate.

Check of outdoor unit

A
Turn ON the power supply.
Is there 230V AC to
L N
between - on the
outdoor terminal block
Yes
MU-GA80VB
No
Check the outdoor power supply
and connection of wiring.
?
Compressor
does not operate.
Is there 5V DC between
No
J101 + - J401 on the deicer
P.C. board? w
Yes
Operate the unit in
COOL mode by
pressing the EMERGENCY
OPERATION switch.
3minutes after the power supply
No
turns ON, is there 230V AC
between A1-A2 on the
compressor contactor (52C)?
Yes
Is there 230V AC between
No
2/T1 on the compressor
contactor(52C) and N on the
outdoor terminal block?
Yes
Check the compressor.
Refer to page 25.
Outdoor fan motor
does not operate.
Is there 5V DC between No
J101 - J401 on the deicer
+
P.C. board? w
Yes
Operate the unit in
COOL mode by
pressing the EMERGENCY
OPERATION switch.
Is there 230V AC between
No
CN711 1-3 or 2-3 on the
deicer P.C. board? w
Yes
Check the outdoor fan
motor. Refer to page 25.
Is there 230V AC between
No
CN730 1-3 on the deicer
P.C. board? w
Yes
Replace the
deicer P.C. board.
Replace the
deicer P.C. board.
Is there 230V AC between
No
1/L1 on the compressor
contactor(52C) and N on the
outdoor terminal block?
Yes
Replace the compressor
contactor(52C).
Is there 230V AC CN730
No
1-3 on the deicer P.C.
board? w
Yes
Replace the
deicer P.C. board.
Replace the
deicer P.C. board.
26
Rectify the connecting
wire.
Rectify the connecting
wire.
Rectify the connecting
wire.
w Refer to page 29.