Samsung AG042KSVANH Service Manual page 83

IPM [IGBT] breakdown diagnostics (Inverter PCB)
1. Preparations before checking
1) Power Off.
2) IPM failure, discharge mode may not work properly. Therefore, wait more than 15 minutes after the Power Off.
3) Remove all of the Inverter PCB connectors and wire that is fixed as screw.
(Include wire that is fixed to compressor and DC Reactor.)
4) Prepare the digital multi tester.
2. Inspection Method
1) Refer to Figure1 and Table1, respectively the resistance value and diode voltage value measure.
2) According to the criterion in Table 1 to determine whether the failure of IPM.
Division
Measure
the resistance values
Measure the diode
voltage values
Measured Point
+ -
P-IGBT U
P-IGBT V
P-IGBT W
More than 3
U N-IGBT
V N-IGBT
W N-IGBT
U P-IGBT
V P-IGBT
W P-IGBT
N-IGBT U
N-IGBT V
N-IGBT W
< Table 1 >
< Figure 1 >
Criterion
Measurement error can occur for reasons such as the initial
measurement condenser discharge.
Measured over at least three times.
0.3~0.7V
79
Remark
Inverter PCB