Mitsubishi Electric SVZ-KP18NA Service Manual page 23

10-5. TROUBLESHOOTING FLOW
A How to check inverter/compressor
Disconnect the connector (CN61) between
compressor and the intelligent power module
(IPM).
Check the voltage between terminals.
Are the voltages balanced?
Check the compressor.
B Check of open phase
● With the connector between the compressor and the intelligent power module disconnected, activate the inverter and check if
the inverter is normal by measuring the voltage balance between the terminals.
Output voltage is 50 - 130 V. (The voltage may differ according to the tester.)
<< Operation method (Test run operation)>>
1. Press the TEST (RUN) button twice.
2. Press the MODE button and switch to the COOL (or HEAT) mode.
3. Compressor starts at rated frequency in COOL mode or 58 Hz in HEAT mode.
4. Indoor fan operates at High speed.
5. To cancel test run operation, press the ON/OFF button on remote controller.
<<Measurement point>>
at 3 points
BLK (U) - WHT (V)
BLK (U) - RED (W)
WHT(V) - RED (W)
NOTE: 1. Output voltage varies according to power supply voltage.
2. Measure the voltage by analog type tester.
3. During this check, LED of the inverter P.C. board fl ashes 9 times.
(Refer to "10-6. TEST POINT DIAGRAM AND VOLTAGE".)
C Check of compressor
Refer to 10-5. "Check of compressor
winding".
Is the compressor normal?
Refer to 10-5. "Check of compressor
operation time".
Does the compressor operate continuously?
OK.
TCH022
No
Yes
Measure AC voltage between the lead wires at 3 points.
No
Yes
No
Yes
See 10-5. "Check of open phase".
Replace the inverter P.C. board.
See 10-5. "Check of compressor".
Replace the compressor.
Refer to 10-5. "Check of compressor start failure".
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