MITSUBISHI ELECTRIC MUZ-GB50VA - Manual (Page 26)

26
C C Check of R.V. coil
No
Yes
No
Yes
No
Yes
No
Yes
No
Yes
1. Disconnect the lead wire leading to the compressor.
2. 3 minutes after turning on the power supply, start EMERGENCY
OPERATION in HEAT mode.
Is there voltage of 230V AC between pin1 and
pin 2 at connector CN912?
W
Turn off power supply of indoor and outdoor unit.
1. Turn off power supply of indoor and outdoor unit, and
disconnect the connector CN781 in the outdoor electronic
control P.C. board.
2. 3 minutes after turning on the power supply, start
EMERGENCY OPERATION in HEAT mode.
Replace the 4-way valve.
Replace the noise filter P.C. board.
Replace the R.V. coil.
Is there voltage 12V DC
between the connector CN781
pin 5 (+) and pin 3 (-)?
Replace the electronic
control P.C. board.
Disconnect the connector
CN912 in noise filter P. C.
board. Is there normal
resistance to R.V. coil?
1. Disconnect the lead wire leading to the compressor.
2. 3 minutes after turning on the power supply, start EMERGENCY
OPERATION in COOL mode.
Is there voltage of 230V AC between pin1 and
pin 2 at connector CN912?
W
1. Turn off power supply of indoor and outdoor unit, and
disconnect the connector CN781 in the outdoor electronic
control P.C. board.
2. 3 minutes after turning on the power supply, start
EMERGENCY OPERATION in COOL mode.
Replace the 4-way valve.
Replace the noise filter P.C. board.
Is there voltage 12V DC
between the connector CN781
pin 5 (+) and pin 3 (-)?
Replace the outdoor electronic control P.C. board.
W If the connector CN912 is
not connected or R.V. coil
is open, voltage occurs
between terminals even
when the control is OFF.
• When heating operation does not work.
• When cooling operation does not work.
The cooling operation or heating operation does not operate. (LED display: Both LED1 and LED2 lighting)
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