Checking Key Components Of Outdoor Unit; Compressor - LG AH-W096A0 Service Manual

Checking Key Components of Outdoor Unit

2. Checking Key Components of Outdoor Unit

2.1 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 How long is power on during
operation?
Does failure appears again
2
when starting operation?
Method to measure insulation
resistance
Comp.
Figure 1.
Method to measure coil
resistance
Comp.
U
V
W
Figure 2.
[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 frequen-
cy 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 fail-
ure 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).
Copyright ©2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
1) Power on for 12 hours or more
2) Power on for 12 hours or less
1) The compressor stops and same
error appears again.
2) If output voltage of the inverter is
stably.
pipe
Motor
Ω
Motor
Ω
3) If output voltage of the inverter is
unstable or it is 0V.
(When incapable of using a digi-
tal tester)
) if using commercial frequency tester when measuring output values of
Symptom
- 54 -
Countermeasure
• Go to No.2.
• Go to No.2 after applying
power for designated time (12
hours).
• Check if IPM failure is occurred.
• Check coil resistor and insula-
tion resistor. If normal, restart
the unit. If same symptom
occurs, replace the compres-
sor.
• Insulation resistor: 2 or more
• Coil resistor:
Inverter
(ANB42FBDMT)
U-V 0.188±7%
V-W 0.188±7%
W-U 0.188±7%
• Check the IPM.
If the IPM is normal, replace
the inverter board.
• Check coil resistor and insula-
tion resistor.
LGE Internal Use Only
at 20°C