15 Amp buss fuse blows at automatic transfer

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Shep
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Posts: 1
Joined: Fri Jun 14, 2024 3:50 pm

Hello,
Model 0052430 Ser. 4431570, 16 KV whole house back up, Natural Gas

This has happened twice now:
1. Unit in AUTO mode,15A buss fuse on the control panel blows when attempting to switch on when street power fails
2. Replaced fuse and started in manual - started and ran without issue.
3. Set unit to AUTO.
4. Set exercise time, unit started and ran normal exercise. Exercise runs every week without issue.
5. Next time power fails (4 months later), fuse blows and unit will not switch on.
6. Repeated 2, 3 & 4. Unit restarted and ran.
7. Following power restoration, switched to AUTO, reset exercise. Exercise ran successfully.

I do not have test equipment, I have checked wires to ensure secure connection and find any worn insulation. All connections were secure and I did not find problems with insulation.
I have not messed with the control board but I did not see any burn or short marks on it. There was no burnt electrical smell that I could detect.

Battery replaced 27 months ago. Oil has been changed annually every October since installation in July 2006.

Hope someone can provide a direction on where to go from here.
Thanks in advance for your assistance.
Regards,
Shep
Chris
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Location: Clawson, MI
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In many cases a failing starter can cause issues like this. I don't think you meant to put the title as 15A fuse blows in transfer switch though... That would be at the generator, not the switch.

Without any kind of testing equipment, it's going to be guessing at parts.
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