E E How To Check Inverter/ Compressor - Mitsubishi Electric MXZ-2A40VA Service Manual

• When heating, room does not get warm.
• When cooling, room does not get cool.

E E How to check inverter/ compressor

LED display:
Disconnect the terminal of the compressor. 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(48Hz) HEAT: 170V(64Hz)
Is voltage output? W1, W2
(MXZ-2A) Yes
Is output balanced?
Is the input voltage to the outdoor electronic
control P.C. board 370V or more?
Turn off power supply of indoor and outdoor unit,
and measure the compressor winding resistance
between the compressor terminals.
Is the resistance between each terminal normal?
Reconnect the lead wire of compressor, and turn on
power supply to indoor and outdoor unit.
3 minutes later, starts 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
W1 • After the outdoor fan starts running, wait for 1 minutes
• The output voltage values have the tolerance of i20%.
W2 • The output differs depending on the capacity or the
No
Yes
No
(MXZ-3A/4A)
Yes
Yes
Yes
LED2
Lighting
Twice
Goes out
or more before measuring the voltage.
number of indoor units to be operated.
No
Replace the inverter P.C. board or
the power board.
No
Replace the
compressor.
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