Troubleshooting Flow - Mitsubishi Electric SUZ-KA25VA3 Technical & Service Manual

11-5. TROUBLESHOOTING FLOW

A How to check inverter/compressor
Disconnect the connector between compressor
and the intelligent power module (IC700).
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 - 130V. (The voltage may differ according to the tester.)
<< Operation method (Test run operation)>>
1. Press the EMERGENCY OPERATION switch or the Test button to COOL or HEAT mode.
2. Test run operation starts and continues to operate for 30 minutes.
3. Compressor starts at rated frequency in COOL mode or 58Hz in HEAT mode.
4. Indoor fan operates at High speed.
5. After 30 minutes, test run operation finishes and EMERGENCY OPERATION starts.
6. To cancel test run operation (EMERGENCY OPERATION), press the EMERGENCY OPERATION switch or 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 11-6-1.)
C Check of compressor
D
Refer to 11-5. "Check of compressor
winding".
Is the compressor normal?
E
Refer to 11-5. "Check of compressor
operation time".
Does the compressor operate continuously?
OK
OCH530
No
Yes
* Measure AC voltage between the lead wires at 3 points.
No
Yes
No
Yes
B
See 11-5. "Check of open phase".
Replace the inverter P.C. board.
C
See 11-5. "Check of compressor".
Replace the compressor.
Refer to 11-5. F"Check of compressor start failure".
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[SUZ-KA25/35/50VA3.TH]