Igbt-Transistor Testing; Secondary Diodes Testing - Kemppi miniarc 140 Troubleshooting Manual

IGBT-transistors testing
Discrete-IGBT (50 A, 600 V) can be tested with the IGBT-tester.
When replacing damaged IGBT-transistors the whole set
must be always replaced. The gate resistors (10Ω) must be checked
and replaced if necessary. Spare part IGBT set 4297750.
Discrete-IGBT tightening torque to the heatsink is 0,6...1,2 Nm!
Testing the secondary diodes
When testing the secondary diodes the other coil end of the main
transformer T001 has to be disconnected. The main transfomer
coils and connectors may not be bent!
If the secondary diodes are in short circuit, the power source
doesn´t start.
Secondary rectifier unit 4297740.
The tightening torque for the secondary diodes is 0,6...1,2 Nm!
Solderings should be done carefully, because of high currents,
approx. 30 A/ leg!
60 A, 200 V types APU02 or 2141
60 A, 400 V types APU04 or 2154
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