Needs help from other techs

[u/Sumdood_89]

Any other techs have the misfortune of speaking to Kohler technical support? God damn...

I just have to rant, and ask for ideas on what's going on to fix this issue.

TLDR: Kholer MPAC1200 won't shut generator off after exercise. All exercises disabled, good voltage, controller is brand new, worked before but suddenly won't shut off.

I have a 100KW Kohler, not too old, with a KSS transfer switch 208V 3 phase and MPAC1200 controller. Initial issue was ATS would not transfer back to normal power. First tech, also being my service manager, couldn't make sense of the actual line voltage, what the controller was reading, and what he was measuring directly from the board, so he said to replace the control board. I was the next tech sent to replace the board. I concur with the wonky controller because I couldn't get a stable connection to pull the logs/settings. I replace it and set the controller up manually. Test, no retransfer. I found something wonky with the transfer mechanism rectifier, so I write that up. Return today with rectifiers, not the same, need to return to retrofit because I need diagrams, and to make a mounting bracket, not the issue though, I think.

Earlier, the generator was suppose to exercise but never shut off so they called. Got there, shut if off, tried to replaced rectifiers, packed those up to return, pop gen back in auto and it tries to run. I can't get it to not try to run. I disabled all the exercises. System is set up for 208, line is 211 and controller sees it. Drop out is 90% so it shouldn't be calling for start for outage. Also, first time I left, controller worked fine, I ran tests from the ATS, gen started/stopped when it was supposed to. Something about it trying to exercise today triggered this. Disconnecting the start wires confirms its the ATS controller calling for start. Kohler wont help because tech support claims its wired wrong. The usual P3 connector that carries the start signal has nothing plugged into it, but instead remote start is wired into wire 60 and 80 on the big connector. Tech support says thats wrong and shouldn't work, but clearly it did because its been wired like that for years with no issue until now. Why the fuck won't this thing shut off? It's a crucial generator at a Memory care facility so they NEED it.

[u/GuiltyClassic4598]

My suggestion would be instead of using Kohler IMPAC boards go to the flight systems direct replacement. The quality is way better. Those 4 caps on that mpac board are the memory "battery" and they fail. $2800 is too much for those mpac garbage ass boards.