Mitsubishi Electric MXZ-A14WV Service Manual page 62

• When heating, room does not get warm.
• When cooling, room does not get cool.
E E Check of inverter/ compressor
MXZ-A14/A18WV LED display:
Start
Disconnect the terminal of the compressor at terminals. 3 minutes after turning on the power
supply, start EMERGENCY OPERATION.
Measure the voltage between each
lead wire leading to the compressor.
U (BLK) - V (WHT)
V (WHT) - W (RED)
W (RED) - U (BLK)
Output voltage
COOL: 150V(58Hz), HEAT: 150V (58Hz)
Is voltage output? W
Yes
Is output balanced?
Yes
Turn off power supply of indoor and outdoor unit,
and measure the compressor winding resistance
between the compressor terminals.
Is there resistance of 0.53" to 0.66" between
the each terminals?
Yes
Reconnect the lead wire of compressor to former, and
turn on power supply to indoor and outdoor unit.
3 minutes later, start EMERGENCY OPERATION.
Clarify the causes by counting time until the inverter stops.
0 to 10 seconds: compressor rare short
10 to 60 seconds: compressor lock
60 seconds to 5minutes: refrigerant circuit defective
5 minutes or more: normal
LED1
Lighting
Lighting
Twice
W • After the outdoor fan starts running, wait for 1 minutes or more before
measuring the voltage.
• The output voltage values have the tolerance of i20%.
No
No
LED2
Lighting
Twice
Goes out
Replace the outdoor electronic
control P.C. board.
Replace the
No
compressor.
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