LG Multi-Inverter Service Manual page 75

4. Trouble Shooting
I 27/30/40k
1. Wait until inverter PCB DC voltage is discharged after main power off.
2. Pull out V, V, W 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
27 26
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.
Copyright ©2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
V W Nu Nv Nw
25 24 23 22 21
0.4 ~ 0.6 V
LED01M LED01M LED01M
U,V,W CONNECTOR
P U V W Nu Nv Nw
27 26 25 24 23 22 21
- 74 -
LED02M LED02M LED02M
U U
V V
W W
0.4 ~ 0.6 V
PFC_IPM chec
U, V, W ➔ R S
LGE Internal Use Only