Chapter 7 – Trouble Shooting & Maintenance
7-10
3) Power Component Check – 150 HP ~ 250 HP
Module
Test polarity
Reading Module
Test polarity
Reading
+ -
+
-
DC Bus
Fuses
Fuse 1 across fuse Closed
Fuse
Indicators
Fuse 1 across indicator Closed
Fuse 2 across fuse Closed Fuse 2
across indicator
Closed
Fuses are in parallel, visual check indicators first
SCR's
SCR1
R P2 (+) Open
Diodes
D4
R N (-) Open
P2 (+) R Open N (-) R Closed
SCR2
S P2 (+) Open
D5
S N (-) Open
P2 (+) S Open N (-) S Closed
SCR3
T P2 (+) Open
D6
T N (-) Open
P2 (+) T Open N (-) T Closed
All SCR's have a snubber circuit across them.
IGBT's
Tr1(1a)
U P2 (+) Closed
IGBT's
Tr4(4A)
U N (-) Open
P2 (+) U Open N (-) U Closed
Tr3(3a)
V P2 (+) Closed
Tr6(6A)
V N (-) Open
P2 (+) V Open N (-) V Closed
Tr5(5a)
W P2 (+) Closed
Tr2(2A)
W N (-) Open
P2 (+) W Open N (-) W Closed