Kemppi Master S 400 Service Manual page 17

Service manual Master S 400 and 500
IGBT module has 4 IGBTs and
each one of these has diode in
parallel. Module has also
integrated NTC thermistor for
overheat protection.
Check the diodes using the multimeter diode function to measure their threshold voltage. Diodes must be
measured both forward bias and reverse bias condition to make sure they are ok. NTC is measured in
resistance mode. See following pictures and table to make all the necessary measurements.
1
3
15
Kemppi Oy
IGBT
Parallel
diode
DC-link positive
Output 2
2
Output 1
4
Ground
Version 1.1
IGBT module
5.9.2014