Mitsubishi Electric MUH-GA50VB-E1 Service Manual page 29

MUH-GA60VB
MUH-GA80VB
Turn ON the power supply.
Is there 230V AC to
L N
between - on the
outdoor terminal block
Yes
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 or HEAT mode by
pressing the EMERGENCY
OPERATION switch.
3minutes after the power
supply turns ON, is there No
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 10-3.
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 or HEAT mode by
pressing the EMERGENCY
OPERATION switch.
Is there 230V AC between
CN711 2-3 (MUH-GA60VB)/
No
CN711 1-3 or 2-3
(MUH-GA80VB) on the
deicer P.C. board? w
Yes
Check the outdoor fan
motor. Refer to 10-3.
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.
29
Rectify the connecting
wire.
Rectify the connecting
wire.
Rectify the connecting
wire.
w Refer to 10-5.