I did the "replace the fuses and try again" thing the moment I found them blown, and had high hopes that there was no further problem, but as I stated in another post in this thread, when the second one was replaced, both blew again. That tells me that something was damaged when the problem arose. I am only speculating that the induction furnace was the cause, as I have no idea when the machine died. It was fine about a year ago, when I fired it up so I could make a copy of the operating system in case I had a battery fail.John Hasler wrote: ↑Sat Jun 09, 2018 7:53 amSingle phasing with no motors running should not have harmed the electronics but the spike may have. It's possible that the fuses did their job and protected the machine from further damage. I'd determine what the fuses protected, inspect for visible damage, and if I found none replace the fuses and try again. Are the fuses in the AC side? Do you have documentation?
It is unusual for us to get lightning in this area. Where I resided in Utah, that was not the case. I can pretty much dismiss lightning as the problem as a result, and the only thing that I can think of would be the blown fuse on the primary side of my service. We've had several power outages, too, so I assume I can't dismiss them as a possible cause, although we've had many previously, all with no problems resulting. How I wish I had not left the panel live. This problem may not have occurred, but I guess I'll never know.
I haven't spent any time looking at this thing, so I don't know that I can answer the question as to the fuses being on the AC side, but I believe they are. I have full documentation on the machine, but I'm not convinced they provide schematics for one to troubleshoot. I certainly don't recall seeing any, but then I wasn't looking for them, either. I was too involved in trying to learn operational procedures to worry about that---and it's been too long for me to remember anything more. When I am ready to tackle the repair, I'll take a second look. Mean time, I have a lot to do, so it's on the back burner for now.
Thanks for your thoughts, John.