31
Cooling operation does not work.
•
Is there voltage of 230 VAC between pin1 and
pin 2 at connector CN912?
Disconnect the lead wire leading to the compressor.
3 minutes after turning on the power supply, start EMERGENCY
OPERATION in COOL mode.
1.
2.
Turn OFF power supply of indoor and outdoor unit, and
disconnect the connector CN781 in the outdoor electronic
control P.C. board.
3 minutes after turning ON the power supply, start EMER-
GENCY OPERATION in COOL mode.
1.
2.
Yes
Is there voltage 12 VDC between the connector
CN781 pin 5 (+) and pin 3 (-)?
No
Replace the noise
fi
lter P.C. board.
Replace the outdoor electronic control P.C. board.
No
Replace the 4-way valve.
If the connector CN912 is not connected or
R.V. coil is open, voltage occurs between
terminals even when the control is OFF.
MUZ-GB50VA-
E1
/
E2
Heating operation does not work.
•
Is there voltage of 230 VAC between pin1 and
pin 2 at connector CN912?
Yes
No
Disconnect the lead wire leading to the compressor.
3 minutes after turning on the power supply, start EMERGENCY
OPERATION in HEAT mode.
1.
2.
Turn off power supply of indoor and outdoor unit, and discon-
nect the connector CN781 in the outdoor electronic control P.C.
board.
3 minutes after turning ON the power supply, start EMER-
GENCY OPERATION in HEAT mode.
1.
2.
Turn OFF power supply of indoor and outdoor unit.
Is there voltage 12 VDC be-
tween the connector CN781
pin 5 (+) and pin 3 (-)?
No
Disconnect the connec-
tor CN912 in noise
fi
lter
P.C. board. Is there normal
resistance to R.V. coil?
No
Replace the R.V. coil.
Replace the 4-way valve.
Replace the noise
fi
lter P.C. board.
Yes
Replace the outdoor
electronic control P.C.
board.
Yes
H Check of R.V. coil
Summary of Contents for MUZ-GB50VA
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