Power from my 20k generac only auto switches to half the house

Automatic/Manual transfer switch repair, wiring & troubleshooting questions
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New Member
New Member
Posts: 1
Joined: Thu Aug 08, 2019 8:16 pm

Thu Aug 08, 2019 8:22 pm

Hi, my generac 20k has worked great for 3 years, but now when power fails it only auto switches to half of the house. I mentioned this to the service person a few months ago and he told me it was easy to fix and told me what to do.... the only problem is I can’t remember! And they are out of business. Any troubleshooting thoughts would be appreciated.
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Joined: Sat Aug 04, 2018 8:46 pm
Location: Clawson, MI

Fri Aug 09, 2019 9:35 am

Hmm, to be honest, this doesn't sound like an 'easy fix' to me... There are a few scenarios here that could be causing the issue:

1. A bad main breaker in the unit only allowing 1 phase of the 240V power through. Fix is 'fairly' easy and not too pricey.
2. A bad contactor assembly in the transfer switch allowing only 1 phase of power to get through. This usually requires replacement of the contactor assembly and it's not a super cheap part and a fairly involved fix.
3. A bad wiring connection somewhere in a splice or at the generator or switch. Easy fix as long as nothing has melted or burned up from the bad connection.

Hope this helps. A little troubleshooting with a good digital meter would tell you where the problem lies :cool:
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