Phase Bridge Diode Checking Method - LG ARUN Series Service Manual

2.4 Phase Bridge Diode Checking Method

Internal circuit diagram
1. Wait until inverter PCB DC voltage gets discharged, after the main power switch off.
2. Pull out all the connectors connected with 3 phase bridge diode.
3. Set multi tester in diode mode.
4. Measured value should be 0.4~0.7V 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 M Ω), PCB needs to be replaced.
6. In case that bridge diode is damaged, check if inverter PCB assembly(IPM) is needed to be replaced.
Diode terminal
Tester terminal
R(~) : red(+)
S(~) : red(+)
T(~) : red(+)
R(~) : black(-)
S(~) : black(-)
T(~) : black(-)
✽ Red(+) and black(-) are the measuring terminals of multi tester.
• Check the electric parts of c/box, 10 minutes after switching off the main supply and
Caution
checking DC voltage is discharged. Otherwise, there is chance of getting electric
shock.
• There is chance of electric shock by charged voltage.
Copyright ©2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
+ terminal: black(-)
0.4 V ~ 0.7 V
0.4 V ~ 0.7 V
0.4 V ~ 0.7 V
-
-
-
- 67 -
Checking Method for Key Components
Appearance
- terminal: red(+)
-
-
-
0.4 V ~ 0.7 V
0.4 V ~ 0.7 V
0.4 V ~ 0.7 V
R
S
T
LGE Internal Use Only