I am considering purchasing a 3000 watt emergency generator. At this
size, some generators are 110/220 and others are only 110 volt.
My load will be a 5000 BTU A/C and a refrigerator. In addition, I
would like to put 110 Volts across the water heater for 1/4 power for a
few hours when the load could take it.
Assume that the main breaker is off.
I can backfeed 2 receptacles on the opposite side of the box with 2
extension cords and feed any 120 loads within the breaker limits.
But what about the water heater? How would you suggest that I connect
120 across it?
If you do this, and I sincerely hope you will not, make darn sure all the
240v breakers are off. In fact, make sure all the breakers are off.
If I were going to do it, and I wouldn't do it, I would cut the cable to the
water heater, put a 120v plug and outlet on it. Then it is a simple matter
to run the heater off an extension cord. Or, if you are really crazy, plug
it into a backfed 120v outlet and run it that way. Make sure you use a 30a
plug and outlet; although it won't draw that much on 120v, it will on 240v.
I suppose it would be better to use a 240v plug and outlet, and make a
converter with a 240v outlet and a 120v plug, though it is so foolish it
really doesn't matter.
It sounds like an accident waiting to happen. Besides, I doubt the heater
will get hot enough to work. I have a 240v baseboard heater wired to 120v.
It is fine for late spring and early fall when I use it, but it barely warms
Please don't run your A/C off the generator at night. If my neighbor did
that... well, I hope he doesn't. It is one thing to run a furnace or
refrigerator, but an A/C?!
There is no point in feeding the panel with a piddly little 3Kw generator.
Use extension cords to the devices. He's going to have to juggle the loads
I'd use a 240V plug, and a short adapter cord for use with the generator.
[120V plug to 240V socket.] The 240V plug has to be wired adequately
(probably #10) for full line current, the adapter and extension cord
need only be beefy enough for half the HWT's amp rating (14 or 12ga if
This is a code violation tho without very careful attention to wire
types (even then, but never mind).
But don't do this - see below for a simpler and less expensive
120V to a 240V water heater works just fine. My inlaws had theirs wired
that way by some idiot electrician. The drawback is that recovery time is
_abysmally_ slow (4 times slower). You can imagine what a house with
this problem and four women in it is like when it comes to showers.
Fixing that water heater recovery time went a long way towards them
allowing me to marry their daughter ;-)
Don't do it, because it's tremendously wasteful, and when you're on a generator,
it's a bad time to waste power.
It's more effective/useful to buy an 120V electric kettle (it'll
cost less than the adapter cord alone and doesn't require screwing around
with the HWT circuit or the inevitable code violations). Heats a lot
faster too. Or use a propane stove.
[240V to a 120V water heater also works okay, for a couple of weeks, then
the elements eventually fry.]
Chris Lewis, Una confibula non set est
It\'s not just anyone who gets a Starship Cruiser class named after them.
He wants to be able to take a hot shower, even if it is only a very short
one. Hard to do that with a teakettle. I can stand sponge baths for a day or
three at most, personally- if I can't get a shower, or a
warm-enough-to-jump-in lake/river by then, I get Real Cranky. That much, I
do understand. Rather than screw around with hot-wiring an electric heater,
if gas service was available, I'd put in a gas water heater.
Even a refrigerator. If it's cold inside at bedtime, it will still be
cold in the morning, and neighbors can have a good night's sleep.
A furnace runs when everyone's windows are closed.
During a power failure, AC runs when most people will have their
windows open, and at night they are trying to sleep.
Some food that thaws won't taste as good if it is refrozen and thawed
again, but that doesn't mean it's inedible. And there is no need to
refreeze it. One can keep it cold after it has thawed and eat a bunch
of it each day (if there is a way to cook.) I'm pretty sure frozen
dinners are all nuked these days, because when my refrigerator
wouldn't get very cold (fan stuck) and the freezer wouldn't get below
40 for weeks, no frozen dinner spoiled. It took me about 30 days to
eat them all.
Remove NOPSAM to email me. Please let
me know if you have posted also.
Your local power company will be very upsets with any home brew attempt
to do this. I don't blame them. It has a tendency to kill workers.
You little generator is not going to do all you want it to do. The
specs are generally greatly optimistic. If you want to run A/C get a real
generator and have it properly installed.
What you do with the wires inside your house is none of their business, IMO.
Would you have any evidence for this article of faith?
Why not heat water on a regular basis in wintertime with Honda's 6500 W
water-cooled generator in an exhaust-depressurized plastic film room in
the basement, with a CO detector? Item# 1676-1601 at NorthernTool.com.
The description says "744.5dB@7.7yards" :-) Running 4.7 hours on 4.2 gallons
of gas, it could make 4.7x6.5 = 31 kWh of electricity and 4.2x114K/3412-31
= 110 kWh of "waste heat." About 4'x2'x2', 309 pounds, with wheels.
Play the troll if you like, but please don't make such irresponsible
remarks. It could cost a life. As long as your wires are connected to
their system they certainly do have a right to control what you do with
those wires. If you don't believe me as you attorney.
We hope the main breaker is off. The house is not on the grid, but
likely some poor work crew is trying their best to get it back on and they
could face 120V where it should not be. It is for that very reason that the
power companies and local authorities require a professional system to
provide a fail safe system to prevent feedback into the grid. An excuse
like you have no right to tell me what to do with the wiring in my home or I
thought the main breaker was off, is not going to do much after an accident.
It is also foolish since how you wire you home is governed by the electric
code. You don't have the right to decide what to do with your own wiring.
Didn't we just do this same topic to death a few weeks ago?
Either use extension cords directly to the devices, or put in a proper
transfer switch. Unless your mains have a place to do a padlock lockout, and
you keep the key in your pocket, there is always the chance some fool will
flip it with the generator on, and backfeed the grid. Even with the lockout,
under certain circumstances of a failure in your wiring, the neutral bus
could go hot all the way back to the (usually shared) can on the pole. Not
likely, but possible, so it is stupid to take the chance when safer methods
EMERGENCY!!! means an unforseen situation. You are obviously planning in
advance, which is good, but it also means 'lack of the proper hardware' is
not a good excuse. If you have the cash for the generator, you can also
afford the hardware to connect it properly. These codes and standards of
practices were developed for a reason- to protect utility workers, fire and
rescue crews, and even you and your family. No, they can't prevent you from
wiring your place like you want, but if/when they find out, they can also
disconnect you from outside power till they are satisified you are playing
by the rules.
The 'assume' that the3 breaker is off, was for you guys in answering my
question. For me, I AM DARN SURE!
On this thread I have learned the following:
"120V to a 240V water heater works just fine. My inlaws had theirs
that way by some idiot electrician. The drawback is that recovery time
_abysmally_ slow (4 times slower). You can imagine what a house with
this problem and four women in it is like when it comes to showers. "
In addition, if I timeshare the refridge with the water heater, and
keep the 5,000 BTU A/C running, the 3,000 watt generator should
Longer run times, less noise, lighter, and OK for an EMERGENCY!
If you had seen the miles l----o------n------ g (no) gas lines after
Wilma, you would understand my concern about using as little gas as
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