Filter
Top Products
Chapter 8 - Troubleshooting & Maintenance
8-6
8.4 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) is discharged.
1) Disconnect the power input line (R, S, T) and the inverter output to the motor (U, V, W).
2) Verify whether the inverter terminal R, S, T, U, V, W, B1 (or P/L1), N is shorted or open by changing the polarity of the
tester.
3) Verify capacitor has discharged before testing.
4) The tester should display several mega-ohms when open. The tester can display terminal is shorted for a short time and
then display several mega-ohms because of the electrolytic capacitor. The tester should display x Ω ~ xx Ω when
terminal is shorted. If all measured values are about the same, individual modules are OK.
4) Diode module and IGBT module checking points:
Test Polarity Test Polarity
Elements
+ -
Measured
Value
Element
+ -
Measured
Value
R DCP+ Short R N Open
D1
DCP+ R Open
D4
N R Short
S DCP+ Short S N Open
D2
DCP+ S Open
D5
N S Short
T DCP+ Short T N Open
Diode
Module
D3
DCP+ T Open
D6
N T Short
U B1 Short U N Open
Tr1
B1 U Open
Tr4
N U Short
V B1 Short V N Open
Tr3
B1 V Open
Tr6
N V Short
W B1 Short W N Open
IGBT
Module
Tr5
B1 W Open
Tr2
N W Short
R
G
E
G
E
G
E
G
E
G
E
G
E
S
T
U
V
W
G
E
P1 P2
B1
N
Dynamic Braking Unit (Option) for 15~30HP models
N
Char
g
e resisto
r
Contacto
r
+
Electrolytic
capacitors
B2
D1 D2 D3
D6D5D4
Tr5 Tr3 Tr1
Tr2 Tr6 Tr4
DCP+