OT: AC's and Generators

[Davist]

To re iterate, a genset is not good with "step loading" (ie turning everything on at once) doesn't have the oomph, so to speak (typically can put out 1.5-2x full load current for a very short time) and you don't typically size a genset for the whole house load, just the "critical" portion anyway, so a fraction of a fraction

A high inrush load (even the old tungsten lightbulbs pull 10x current when you switch on) is therefore beyond its capabilities. Nothing wrong with the genset. When you're on utility power you're able to get short time additional power, which the breakers ignore (inverse time vs load on tripping curve) for a short while to get things going.

All the best, but I think AC is out. I use my genset for the freezer, refrigerator, a few LED lights and the sump pump. Oh, and the router/wifi...

[glepore]

I have a liquid cooled 25kw genset that handles dual heatpumps and everything else no issue. Came with the house. Pricy option but more durable than aircooled.


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[Blown Reek]

Originally Posted by steveandbarb1

Challenge is with Generac - lose power -> Generac wait x seconds then starts up -> whatever devices were on kick in. So: 1 would need to be home, 2 run into basement to trip breaker to AC. This appears unreasonable in real life.

Due to the potential maximum load in my house, my Generac system has a "load shed module" on one of my AC units so when the generator kicks on, it won't run that particular AC unit right away. This prevents what you're describing.

Then again, the load calculations are based on everything running at the same time- both ACs, the washer/dryer, lights, appliances... you name it. With the 38kW, I wouldn't need it except for the fact my tankless water heater runs at 22k watts when it's running (as opposed to about 5k watts for a regular water heater).

In real life, there's no way both ACs, the washer and dryer, the dishwasher, the refrigerators' compressors- basically everything electrical in the house will be running at the same time. However, everything is engineered and the load calculations used for permitting determine either the size of the generator needed and/or the amount of load shed modules.

That's the right way to do it.