27
After 30 seconds,
does compressor stop?
No
Yes
Is there 230V AC between
A1-A2 on the compressor
contactor (52C)?
Replace the
deicer P.C. board.
Yes
1
Turn OFF the power supply.
2
After 30 seconds, turn ON the power supply again.
3
Operate the unit in COOL mode by pressing the
EMERGENCY OPERATION switch.
4
Operate the unit for 1 minute or more and stop it by
pressing the EMERGENCY OPERATION switch again.
Ok
No
After 30 seconds, does
outdoor fan motor stop?
Replace the
deicer P.C. board.
Yes
Ok
No
Is there 230V AC between
2/T1 on the compressor
contactor (52C) and
N
on
the outdoor terminal block?
Yes
Replace the compressor
contactor (52C).
No
Rectify the connecting
wire.
MU-GA80VB
Check of outdoor unit
Compressor and/or outdoor fan motor doesn’t stop.
How to check mis-wiring
C
1. Turn OFF the power supply (indoor/ outdoor unit) and disconnect indoor and outdoor
connecting wire at the terminal block
3
of the indoor unit.
2. Short-circuit terminal block
N
-
3
of indoor unit by lead wire.
3. Turn ON the power supply (indoor unit) and press once EMERGENCY OPERATION switch.
During EMERGENCY OPERATION, is there
10V DC between both ends of R601on the
deicer P.C. board? Refer to page 29.
(By tester, the stylus is between 5 ~10V.)
As for indoor unit,
refer to service
manual OB369.
Start
No
No
Is there 20V DC between both ends of
R132 on the indoor electronic control P.C.
board ?
( By tester, the stylus is between 0 ~ 20V. )
• Turn ON the power supply. (indoor/ outdoor unit)
• Press once EMERGENCY OPERATION switch.
Is this mis-wiring, poor contact,
or wire disconnection?
Make them sure.
Replace the indoor electronic
control P.C. board.
Is there 230V AC between
L
-
N
on the outdoor terminal block?
No
Check the outdoor power supply
and connection of wiring.
Yes
No
Replace the deicer P.C. board.
Yes
No
Make the wiring between CN730
on the deicer P.C. board and
outdoor terminal block correct.
Refer to page 29.
Replace the deicer P.C. board.
Yes
Is there 5V DC between J101 + -J401 -
on the deicer P.C. board?
Refer to page 29.
Yes
Yes
After 3 minutes, mis-wiring is indicated
(0.5-second ON, 0.5-second OFF)
on OPERATION INDICATOR
lamp on indoor unit.
w
w
Short circuit of JPG and JPS on the indoor electronic control
P.C. board enables self -check to be displayed in 3 seconds.
• Turn OFF the power supply. (indoor unit)
Disconnect the lead wire that terminal
block
N
-
3
of the indoor unit is short-circuited.
• Connect ON indoor/ outdoor connecting
wire.
Turn ON the power supply. (outdoor unit)
When OPERATION INDICATOR lamp flashes ON and OFF in every 0.5-second.
Outdoor unit doesn’t operate.
MU-GA80VB
B
OB370-1.qxp 04.10.14 1:45 PM Page 27
