Spindle Drive Fault

I have an Interact l MK II with the KTK drive (Heidenhain TNC2500 Control). When starting the spindle I am getting a "Spindle Dirve Fault" alarm. I can reset and wait and sometimes get it going and it will run for a couple of hours (I work in the evening). When I first installed the machine I could start at lower RPM, but not start at much above 1000. I am running on a 20hp phase converter and I ended up installing some run capacitors and haven't had a problem for over a year. I have 240v. Is there some voltage checks/adjustments on the drive or the interface board I could check? On initial machine start up in my shop one of the capacitors burned up on the MT1-1 board. That was repaired and I have run for over a year. I have no manuals except from Heidenhain.
Thanks for any help.

I have a similar issue with my BP Discovery 308 and the consensus was the power supply for the drives needed new caps as 17 year old caps are beyond there life cycle. I can ramp mine up to 6000 using 200 rpm steps but can't start it over 1800 without getting a drive fault. When I get time I'll replace my caps...

John

What you are saying makes sense. Someone had posted some time ago some service sheets on the KTK drive and the MT1-1 board. I found on the MT1-1 board some adjustments. First was the amp adujustment, I have three different amp meters and I never could get a reading. The second adjsutment was the voltage at 4000 rpm, it was supposed to be 400v acorss the two leads, it was 280, when I truned that up, the spindle started real nice. Where are the caps, on the KTK drive?

I have a Siemens drive and have not looked inside of it yet. I was told by an ex Siemens guy that drive repair shops replace the caps first on old drives and then see if there is anything else wrong...

John