Should I get a 240V generator?

 I'm looking to get a backup generator to ride through the handful of blackouts
we get where I live (not exactly the boonies, but getting out there).  There
are perhaps a half-dozen each winter, ranging in time from some tens of
minutes up to a handful of hours... the longest last year was probably 10
hours (which apparently are due to storms toppling a tree that takes out a
large chunk of transmission line...).  Initially I was thinking of just
getting a good-quality 120V generator, since for the durations of power
outages we have it's not problem to avoid running large loads and hence a
standard ~4-6kW unit should be fine, but then I found that our well pump is
240V.  (...and we have have a small pressure tank, so as soon as the power
goes, we might get another gallon out before the pressure is gone, but that's
about it.)  So... I'm wondering... is it smarter to spring for a costlier
(240V) generator, or better to get a more efficient, 120V (or multi-voltage)
well pump and a less expensive 120V generator?  (Grundfos seems to have some
nice units.)

Besides the pump, the only other 240V appliances are the water heater, the
range, the dryer, and the furnce.  During winter most of our heating is with a
wood stove anyway, so we don't need that.  The water heater would certainly be
missed in a multi-day power outage, though -- but that's an unlikely
scenario...  the range and the dryer we can definitely live without for weeks
at a time.

Any input appreciated,
---Joel Koltner

 

It sounds to me like you need a 220 generator.  Remember that you need to
balance your 110  loads on both sides of the 220 line.  For example, a 6 kW
220 generator can be thought of as 2, 3 kW 110 generators in series, so you
are allowed a maximum of 3 kw from each side.  This is why I wired our
standby generator for 110, so that I could have full output without worrying
about balancing the load...but we have city water and no other 220 loads
that we want to run with our generator.

Vaughn

 

vaughn wrote:


The official US voltage is 120V single phase, NOT 110. If you can't even get
that right, you shouldn't be giving out advice.

Graham

 

It may be the official voltage now, but I am old enough to remember when
everything was labeled 110 volts, then they started using 115 volts, some
started with 117 volts and now most, not all, devices are labeled for 120,
some up to 125 or 130 volts. However, I just bought a line voltage
thermostat that came labeled for 110 volts. So one shouldn't nit-pick over
such minor details. After all, with an allowable variation of + or - 10%,
10% of 120 is 12 volts which could drop the voltage down to 108 volts at the
line. Pretty close to the old 110 rating.

 

Even so and all else being equal, why not give the correct answer since you
apparently know it?

John
--
John De Armond
See my website for my current email address
http://www.neon-john.com
http://www.johndearmond.com  <-- best little blog on the net!
Tellico Plains, Occupied TN
Save the whales, collect the whole set!