Looks like 22's are the new normal for residential auto-transfer.
what surprised me is that I can actually run three Trane a/c compressors with it; granted I start flicking off breakers
for the hot water heaters and the hot tub automatically gets turned off. I lived aboard a boat for three years and have load
management down pretty well. only a few things at a time...
The Generac/Kohler 22kw units use an approx one liter twin cylinder "lawn mower engine" for want of a better term.
I think this is about the limit for air cooled engines unless one has the engineering background of Deutz or whatever.
In this country we typically have gone water cooled then, for less hot spots and longer engine life supposedly. of course cooling systems can fail;
oh those little rubber impellers do fail. Particularly if they have been sitting in the same spot for too long and not run.
So air cooled has its advantages; the fan power on my Generac is remarkably strong. It will toast shrubbery for six feet on one side.
Huge cost difference, at least tripling usually, to take the next steep step up to a water cooled propane/LP powered car engine based generator.
My understanding has always been the Generac engine is a slightly modified B&S Vanguard. I am now on my second Generac unit, the first
was the 20kw at another home. They have never consumed oil; only time I ever saw the mark move was in running for four days and that was hardly anything.
These engines don't use oil. Not like the scandalous use of some modern Subarus, BMW's, etc which consume oil intentionally at a rate most of us would be alarmed by. When was the last time you had to add oil in between car/truck oil changes? I never ever have to; maybe I've just been lucky. And that's pulling an rv with my truck too. And I sure never have to add oil to my gen. Though I admit none of them are high mileage. Either Mobil 1 or Valvoline synthetic, oem, Wix or Purolator PureOne oil filter. Have always put in best oil I could find. This is one machine I do not want problems with.
So I guess the piston ring tech is good enough today that oil is retained well and seems like Generac does a particularly good job of that.
I wonder if there is a design spec for unattended operation, assuming a large enough fuel tank, for up to one week straight?
Both my neighbor and I have similar gens, his is a Kohler, but we have a deal that if either of us is away, we check on the other guy's gen, since both of our power comes off the same line and we almost always go down together. Even if it doesn't use oil, I like to turn the gen off every 12 hours anyway for an hour, if I can, usually during the day.
Otherwise mine comes on every second Saturday at 1pm for an automatic exercise run. Apparently just enough to heat up the engine. On the older 20kw, it ran every week. Apparently with propane, they can do every two weeks and maintain reliability. Runs at reduced rpm during test runs.
), my Briggs use next to no oil..... Just shows to go ya how badly maintained those gens with empty crankcases grs rescued were....
