Inverter Igbtm Checking Method - LG MULTI V Service Manual

2.4 Inverter IGBTM Checking Method

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1. Wait until Comp PCB DC voltage gets discharged, after the main power switch off (10 minutes).
2. Pull out DC_Link connector and U,V,W comp connector connected with Inverter PCB
3. Set multi tester in diode mode.
4. Measured value should be 0.2~0.6 V measuring as below table.
5. In case the measured value is different from the table, set multi tester to resistance mode and measure. If the
value is small(0 Ω) or high( hundreds MΩ), PCB needs to be replaced.
6. In case that IGBTM is damaged, check if comp is needed to be replaced (PCB damaged).
U terminal : red(+)
V terminal : red(+)
W terminal : red(+)
U terminal : black(-)
V terminal : black(-)
W terminal : black(-)
] Red(+) and black(-) are the measuring terminals of multi tester.
CAUTION
• Check the electric parts of c/box, 10 minutes after switching off the main supply and checking DC
voltage is discharged. Otherwise, there is chance of getting electric shock.
• There is chance of electric shock by charged voltage.
U
V
W
P terminal : black(-)
0.2 V~0.6 V
0.2 V~0.6 V
0.2 V~0.6 V
- 95 -
Checking Method for Key Components
CN_U
CN_V
CN_W
CN_INPUT_L1
CN_INPUT_L2
N terminal: red(+)
0.2 V~0.6 V
0.2 V~0.6 V
0.2 V~0.6 V
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