IGBT Test Method
The following procedure will check the inverter transistors
(
IGBTs
)
and diodes
:
1. Disconnect input power to terminals
[
R, S, and T
]
and motor terminals
[
U, V, and W
]
.
2. Disconnect any wires from terminals
[
+
]
and
[
–
]
for regenerative braking.
3. Use a Digital Volt Meter
(
DVM
)
and set it for 1
resistance range. You can check the
status of the charging state of terminals
[
R, S, T, U, V, W, +, and –
]
of the inverter
and the probe of the DVM by measuring the charging state.
Table Legend
Almost infinite resistance
:
#
Almost zero resistance
:
#
0
DVM
DVM
DVM
Part
+
–
Measured
Value
Part
+
–
Measured
Value
Part
+
–
Measured
Value
[
R
]
[
+1
]
#
[
S
] [
–
]
#
0
[
W
] [
+
]
#
D1
[
+1
]
[
R
]
#
0
D5
[
–
] [
S
]
#
TR3
[
+
] [
W
]
#
0
[
S
]
[
+1
]
#
[
T
] [
–
]
#
0
[
U
] [
–
]
#
0
D2
[
+1
]
[
S
]
#
0
D6
[
–
] [
T
]
#
TR4
[
–
] [
U
]
#
[
T
]
[
+1
]
#
[
U
] [
+
]
#
[
V
] [
–
]
#
0
D3
[
+1
]
[
T
]
#
0
TR1
[
+
] [
U
]
#
0
TR5
[
–
] [
V
]
#
[
R
]
[
–
]
#
0
[
V
] [
+
]
#
[
W
] [
–
]
#
0
D4
[
–
]
[
R
]
#
TR2
[
+
] [
V
]
#
0
TR6
[
–
] [
W
]
#
NOTE
:
The resistance values for the diodes or the transistors will not be exactly the
same, but they will be close. If you find a significance difference, a problem may exist.
NOTE
:
Before measuring the voltage between
[
+
]
and
[
–
]
with the DC current range,
confirm that the smoothing capacitor is discharged fully, then execute the tests.
6
15
T
roubleshooting and
Maintenanc
e
6
−
15
T
roubleshooting and
Maintenance
