LG Multi-Inverter Service Manual page 108

1. Wait until inverter PCB DC voltage is discharged after main power off.
2. Pull out CN-L1(R), CN-L2(S), CN-L3(T) and CN-COMP Connector.
3. Set multi tester to resistance mode.
4. If the value between P and N terminal of IPM is short(0Ω) or open(hundreds MΩ), PCB needs to be replaced.(IPM damaged)
5. Set the multi tester to diode mode.
6. In case measured value is different from the table, PCB needs to be replaced.(PCB damaged).
P U V W
27 26 25 24
CAUTION
In case that the control box is opend and before checking electrical parts, it should be checked that the
LED 01M, 02M turned off(wait 7 minutes after main power OFF), otherwise it may cause electrical shock.
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Only for training and service purposes
Nu Nv Nw
P
23 22 21
27
0.4 ~ 0.6 V
U V W Nu Nv Nw
26 25 24 23 22 21
- 107 -
4. Trouble Shooting
0.4 ~ 0.6 V
PFC_IPM check
U, V, W ➔ R S T
LGE Internal Use Only