Blows fuse

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kyf301
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Thu Jul 11, 2019 4:41 pm

Mo.# 04079-3 10 kw. Ser. 3513884 Nat. Gas - I have test gear. All these problems are with no load. Runs for 5 minuets and I shut it down.. Will not restart because of blown fuse. Replace fuse and starts right up, runs for 30 seconds and blows fuse. With meter I find wire 194 goes to ground. Wait a few minuets and then 194 is open. Doesn't make any sense. Need help.
Chris
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Thu Jul 11, 2019 4:53 pm

I would advise removing the 23 and 194 wires from the terminal block and test it like that. It could be a short somewhere in the wiring between the transfer switch and the generator. A high resistance fault like a rubbed through wire may be causing the issue.
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kyf301
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Fri Jul 12, 2019 11:38 am

The unit runs fine with the 194 and 23 wire disconnected from terminal block. I'll look for a grounded wire as you suggested.
78buckshot
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Fri Jul 12, 2019 8:07 pm

I have seen condensation form inside metal conduit, then cause a short in the control wires if they had been skinned during installation.
kyf301
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Mon Jul 15, 2019 3:46 pm

I never found a short or anything. Took all the wires out of the flexible conduit and found nothing. Replaced the 23 and 19 wires back to terminal block and ran the unit and it ran fine. I don't understand how it would run now without really changing anything. I haven't ran it under load yet, but will do soon.
Chris
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Mon Jul 15, 2019 4:35 pm

I bet somewhere there's a very tiny bad spot in a wire. When the short takes some time to blow a fuse, that's a sure sign there is weak insulation somewhere. If it were touching metal it would blow instantly. Hopefully that corrects the problems!
Generac tech for over 12 years. I'm here to help!
"The only source of knowledge is experience" -Albert Einstein
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