Making a generator interlock kit

There are 7 condenser units of various sizes, as well as a lot of other motor loads. I think I can run most likely combinations, but starting them all at once might be a problem.

The main house disconnect/breakers are 800 Amp. Not so much for the load capacity, as to meet code-allowed numbers of sub-circuits. The 800 Amp main panel has 12 (or 13?) 200 Amp sub-panels connected to it with 40-odd breakers in each. Then there are 2 or 3 Lutron panels associated with each 200 amp panel which control (via relay or dimmer) up to 32 circuits each.

I joke that I can send Morse Code to the power company by having the smart-house simultaneously connect/disconnect all the loads at once.

How big the place is is a good question. The architect calculated all floor areas that have a roof over them. It came to over 18,000 sqft. I think a more realistic assessment is in the 10-12,000 sq ft range. You don't count attics, non-living basement areas, porches, or attached garages.

The website below is way out of date, but you can get an idea what we are doing.

-- --Pete "Peter W. Meek"

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But I thought the ground reference at the service entrance was, according to you, unreliable and could not be counted on.

Because the ground and neutral are still bonded at the service entrance, a hot-to-ground fault can still bring the ground lead to the pole up to some potential and harm a lineworker.

According to that scenario, nothing short of interrupting *all* *three* *wires* between house and pole will suffice.

Because I know that most commerical transfer switches don't do that - they only interrupt the two hot legs - I can only surmise that the particular failure mode you discuss is not an issue in the real world. If it were, then those transfer switches would not be code-legal.

Jim