Hello Diwa:

First of all, I’d like to thank you for your explanation, I also know that this discussion is quite old I guess because of the equipment age, anyway I have now a problem with it… I got 6 Simovert MasterDrives DC-AC 6SE 7037-0TJ60-Z, I had a problem with 3 of them, they had the F027 Fault, this one came for a while (hours, days and sometimes weeks) and then disappeared by itself, I found sulfation on the terminals between bus plates (DC-Phases), we checked the optic fibers (we cleaned it), and after we disarmed and armed the drives, the fault apparently disappeared, however in one of the drives, which had not previously had problems, F011 appeared.

We connected Test Box 6SE7090-0XX84-1FK0, and the UCER, UCES, UCET shined, and VREFU and VREFI didn’t shine, we test the firing and found the 2 IGBTs in U phase didn’t work. We disarmed, and found 2 IGBTs and the IGD7 Board burnt, we changed them, but we don’t have a new IGD7, we replaced it for an old one which we don’t know if it works, we also changed IVI Board, SBB board, ABO board (all of them new), we checked optic fibers, and after we connected the test box again, we found all LEDs ok except UCER LED(VREFU, VREFI shines; UCES, UCET don’t shine, and the 24 V LED at left side shines weak, for 27 VDC at D and C it has 21,3 VDC). We know we have to replace the IGD board for a new one, we are doing it, but it’s quite disappointed that we don’t understand the meaning of this LEDs. May you kindly give me an explanation of the meaning of each one, UCER, UCES, UCET, VREFU, VREFI? And Why does 24 V LED shine weak, and have 21 DVC?

By the way we know we have to migrate to a new technologies ASAP.

Thanks a lot