LGRED Heat General Service Manual

Part 5. Trouble Shooting

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Only for training and service purposes

LGE Internal Use Only

▶18,24,30kBtu/h class

25 26 27 29

W V U

NwNvNu

IPM Check Point

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.

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).

27 26 25 24 23 22 21

P U V W Nu Nv Nw

0.4 ~ 0.6 V

27 26 25 24 23 22 21

P U V W Nu Nv Nw

0.4 ~ 0.6 V

PFC_IPM check

U, V, W ‘ R S T