Yaskawa GPD 506/P5 Section One - Manual (Page 37)

PP.P5G5.01.Troubleshoot
Page 37
Rev. 06/11/2003
Parallel Transistors
If the transistor with gain code “G” in the positive portion of T1 shorted, YEA
recommends that all four transistors in that phase be replaced. It is not required
that all four transistors have identical gain codes. Only the transistors in parallel
need to have the same gain code (as shown below). The gain code on transistors
in parallel configurations must be identical.
Code G Code G Code B
Code B
T1 T3 T2
Positive DC Bus
Negative DC Bus
Code B
Code B
Code C Code C
Code F Code F
Code A Code A
Constitutes
1 Phase