Igbt - Kemppi MinarcTig Evo 200 Service Manual

Service manual MinarcTig Evo 200

4.2.1.2. IGBT

Main supply voltage must
IGBT module can be tested by multimeter if using the diode tester function. Module holds four diodes and
in many cases they may be defective if IGBT is damaged. They can be measured separately only if main
transformer primary is disconnected.
DC –link positive
1
IGBT
IGBT 1 diode + upper separate
diode; forward bias condition
IGBT 2 diode + lower separate di-
ode; reverse bias condition
IGBT 1 diode + upper separate
diode; reverse bias condition
IGBT 2 diode + lower separate di-
ode; forward bias condition
If the transformer primary is disconnected, IGBT 1 emitter and IGBT 2 collector connection points can be
used separately to measure diodes one by one. In this case the table must checked twice: first using the
IGBT 1 emitter point only and then the IGBT 2 collector point.
18
Kemppi Oy
not
be connected during the IGBT module diode measuring.
IGBT1 emitter
IGBT2
collector
2
GND
Positive test lead
IGBT1 emitter/IGBT 2
collector
IGBT1 emitter/IGBT 2
collector
DC-link positive
GND
Version 1.1.5.
Negative test lead
DC-link positive
GND
IGBT1 emitter/IGBT
2 collector
IGBT1 emitter/IGBT
2 collector
29.9.2015
Result
0,2-0,7VDC
No value
No value
0,2-0,7VDC