On Sat, 01 Oct 2005 11:17:49 -0500, Don Foreman
wrote:

It occurred to me today (now that there's a genny in my truck) that
powering a whole house with 220 with or without transfer switch
approved by "my betters" is probably not a good approach for
practical reasons.

Most small gensets, with some exceptions, have current limit on each
110-volt phase. Given a 5 KW genny, you must use 5 KW of 220, or 2.5
KW on each 110. But there's no telling how the key loads (furnace,
freezer, fridge, a few lights, maybe a TV and/or a 'puter) would be
distributed between the two phases and certainly no guarantee that
they'd be anywhere near balanced.

12-gage drop cords w/ powerstrips solve that because then I know
exactly how loads are distributed and balanced. I'll need to make
a transfer block for the furnace if it's hardwired, but it might even
have a plug. Matter of fact, I think it does though it's been a
while since I looked at it. If it doesn't have a plug, it certainly
could have and will have.

I've had some interesting conversation about gennies with a neighbor
at the lake in the last couple of days He has a bidness rewinding
big 3phase irrigation motors, also sells and repairs gennys. That
which might be a good genny for a building contractor (Honda) may not
be a good genny for reserve power backup. He cited reasons: seen
smaller Hondas unable to pick up even a furnace motor load.

I was skeptical about that for a bit, but after some thought it is
plausible. Contractor tools mostly use series-wound universal motors
for light weight, low-end torque and often variable speed.
Universal motors don't have nearly the startup surge that induction
motors have, which is often 10X rated run current. I noted that my
4-amp freezer did not like running on 170 feet of #16 extension cord;
it overheated while trying to start and being unable to do so. #16 is
quite ample for 4 amps, but it couldn't hack the start surge. The
freezer ran great when I replaced the cord with 12-gage.

He said that Honda uses electronic voltage regulation while the Winco
just excites the field with a bridge rectifier. Elex can be designed
to do the job, but they're often used to cut cost: put an inferior
generator inside a feedback loop. That can work well as long as
things are within design parameters, but things go to hell fast when
outside the envelope. Cited example: run out of gas while under
load. Cited typical result: fried elex. New elex: $300. I
could fix the elex under normal condx, but it would be a bit tough
doing it by flashlight (even Luxeon flashlight) with no instruments
save those that are battery-powered and only a butane-powered soldern'
ahrn. Bridge rectifiers can fail too, but they're **** simple to
replace. I have several of those little brix in my goodiebox.

The genny now in my truck is a Winco, made by a company in MN that
has been making gennies since 1927. There's another MN company that
mades good gennies too, in Fridley 2 miles from me: Onan. They're
premium where cost is no object: military, industrial, marine and
RV. Well beyond my need and budget. Onan is now owned by Cummins,
has been for a few years now.

Gunner, I did note your suggestion about getting an Onan genny out of
an RV.
Some issues I had with that:
-don't know whether it has 10 hours or 1000
-don't know if it's been maintained or not
-a lot of such stuff get "sold" to the insurance company and then
"junked". Ya gotta know the RV dealer to know when and where
to go dumpsterdiving.

Roy, you can now park your worry beads on this one. The linemen of
MN will be safe from Foremanian folly not codified by my betters.