Newell Gurus

Full Version: Generator shut down with ACs on
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I often wondered if shutting down the generator while the basement ACs are running can hurt the compressors in the AC units. This happens when we switch from generator power to shore power in a campground.

I always turn mine off before shutting down the genny in order to allow the compressors' head pressure bleed off.

Is this necessary?

Would it hurt anything to just shut down the generator while the ACs are running? And then when plugging back into shore power they would start up again?
Tuga, it is always best to shut down any major loads before shutting down the generator. As a matter of fact, it is good to shut down all major loads such as AquaHot heating (AC) or air conditioners, then let the generator idle and cool down a couple of minutes before shutting it down.

I have a manual transfer switch so I can plug into shore power, remove the heavy loads, switch over to shore power and let the genset continue to idle. Have I ever switched over without killing the airs? YOU BET!! The air conditioners have a delay before they will let the compressor kick in after power has been removed so, YES, the blowers should come on as soon as the power is restored and 2-3 minutes later the compressors should start coming on.
Michael,

My transfer switch is automatic, so I can't make the switch over quickly like you do.

I was not aware that the Aqua Hot should be turned off along with the AC units. Thanks for the advice.
The Aqua Hot should only be turned off if it is set to operate on electricity rather than diesel. On electricity, it can pull as much power as an air conditioner.
I agree with Michael, the compressors have a built in delay to allow the head pressure to bleed off.
And I also agree that allowing the gennie to cool a bit is good.

However, I fried the ATS by plugging in while under load. It wasn't supposed to do what it did, but what it was supposed to do and what it actually did resulted in a burned coil in the ATS.

I always completely shut down when going either way from gennie to shore.
Good point Richard. I have a tendency to 'expect' the systems to take care of my carelessness or oversights. Most of the time they do but it certainly is hard on the equipment and they may give up the ghost just to prove a point.