Compressor - LG Therma V ZHBW056A0 Service Manual

1.5 Compressor

Check and ensure in following order when error related with the compressor or error related with power occurs
during operation:
No. Checking Item
1 Is how long power on during
operation?
Does failure appears again
2
when starting operation?
Method to measure insulation
resistance
Method to measure coil
resistance
[Cautions when measuring voltage and current of inverter power circuit]
Measuring values may be different depending on measuring tools and measuring circuits since voltage, current in
the power supply or output side of the inverter has no same waveform.
Especially, output voltage changes when output voltage of the inverter has a pattern of pulse wave.
In addition, measuring values appear largely different depending on measuring tools.
Note
1) If using a portable tester when checking the output voltage of the inverter is constant (when comparing relative
voltage between lines), always use an analog tester. Especially exercise particular caution if the output
frequency of the inverter is low, when using a movable tester, where change of measured voltage values is
large between other lines, when virtually same values appear actually or where there is danger to determine
that failure of the inverter occurred.
2) You can use rectification voltmeter (
the inverter (when measuring absolute values). Accurate measuring values cannot be obtained with a general
portaable tester (For analog and digital mode).
Symptom
1) Power on for 12 hours or more
2) Power on for 12 hours or less
1) The compressor stops andsame
error appears again.
2) If output voltage of the inverter is
stable.
3) If output voltage of the inverter is
unstable or it is 0 V.
(When incapable of using a
digital tester)
) if using commercial frequency tester when measuring output values of
- 67 -
Countermeasure
• Go to No.2.
• Go to No.2 after applying
power for designated time (12
hours).
• Check IPM may fail.
• Check coil resistor and
insulation resistor. If normal,
restart the unit. If same
symptom occurs, replace the
compressor.
• Insulation resistor: 2 MΩ or
more
• Coil resistor:
Please refer to Page 68
• Check the IPM.
If the IPM is normal, replace
the inverter board.
• Check coil resistor and
insulation resistor.
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Only training and service purposes.