Download caution - Benshaw

8 - Troubleshooting & Maintenance
How to Check Power Components
8.7
How to Check Power Components
Before checking the power components, be sure to disconnect AC Input supply and wait
until the Main Electrolytic Capacitors (DCP-DCN) discharge.
DCP
Tr1
Charge resistor
Contactor
D1 D2 D3
R
Electrolytic
capacitors
S
T
Tr5
Tr3
B1
G
G
G
B2
E
E
E
U
V
W
+
G
E
D4
D5
D6
DCN
G
G
G
E
E
E
Current sensing
resistor
Tr4
Tr6
Tr2
1) Disconnect the power input line (R, S, T) and the drive output to the motor (U, V, W).
2) Verify whether the drive terminal R, S, T, U, V, W, B1,B2 is short or open by changing
the polarity of the tester.
3) Verify that the capacitor has discharged before testing.
4) The tester should display several megaohms when open. The tester can display that the
terminal is short for a short time and then display several megaohms because of the
electrolytic capacitor. The tester should display several W ~ several tens W. If all
measured values are almost the same the modules are without fault.
5) The number of each element of the module and the check terminal.
Elements
D1
Diode
Module
D2
D3
Tr1
IGBT
Module
Tr3
Tr5
154
Test Polarity
+
R
B1
B1
R
S
B1
B1
S
T
B1
B1
T
U
B1
B1
U
V
B1
B1
V
W
B1
B1
W
Measure Element
d Value
Open
Short
Open
Short
Open
Short
Open
Short
Open
Short
Open
Short
D4
D5
D6
Tr4
Tr6
Tr2
Test Polarity
+
R
DCN
DCN
R
S
DCN
DCN
S
T
DCN
DCN
T
U
DCN
DCN
U
V
DCN
DCN
V
W
DCN
DCN
W
Measure
d Vlaue
Short
Open
Short
Open
Short
Open
Short
Open
Short
Open
Short
Open