I have always thought of doing this but wonder if it's feasable... in
an emergency situation where 220 is needed to run a tool etc for a short
burst of time...
Since 220 is made up of two 110 volt legs. What would be wrong (
electrical codes aside as this is just a theory) with wiring up a portable
220 volt receptacle with two 110 volt cords comming out of it with male 110
volt plugs? This way a person could plug in each 110 volt plug to
seperate 110 volt receptacles making sure they are on different breakers..?
This in my opinion would make a very safe easy way of using 220 volt
power in a jam.
Again...I am just looking at the theory part of it... Thanks...Jim
It's not as bad as you think. What he is describing has female on one
end and 2 males on the other. If there is a 240V load plugged in and
turn on at the female end, when you plug in one male plug, the other
male plug is energized. If you plug the males in first, you don't have
exposed energized contacts at any point during the hook-up.
Still, it would be a *lot* better to install a 240V recepticle somewhere
and make a proper 240V extension cord.
Wouldn't this mean that his whole house would be fed through breakers
_backwards_? Do breakers care which end the juice is coming in from?
Wouldn't there also be some issues with the neutrals as well? I know
nothing of wiring generators, but it seems like tying the house neutral
to a generators output would cause some problems.
Another curious twist (to me anyway) would be if he plugged the male
plugs into a female receptacle which was miswired (hot/neutral
And what would REALLY be neat to see is what happens if the main isn't
shut off and then utility power is restored.
I'd pay to see that.
As a practical matter.
First, the OP has so little knowledge of electricity that I advise him to
not attempt this.
What he is proposing can be done if the two receptacles are fed from
opposite legs of the breaker.
There is no need for a neutral in a 220v circuit.
It is indeed dangerous, but sometimes there could be a genuine need to
do it. Like if he bought some military surplus 220V items that he
wants to test and then resell on ebay.
I would suggest to check if there are better sources of 220V in the
house, such as electric range or dryer. One could then buy a
plug and put a fuse in the wire.
I agree with everyone else who said to do it the proper way. That is,
in fact, what I am now doing, getting a nice 220/110v subpanel in the
No, just the one breaker he is backfeeding through. The remainder of the
breakers will work in the normal fashion.
Oh man. That could be scary....
I've been using a very similar setup for the last 15+ years. I only need to
use it about once a year, but it's a lifesaver when I need it.
I flip the main, plug in my dual male pigtail to a 30A unused dryer circuit
and then run cable out to the generator for the 1/2 day that it's needed.
Good Lord no.... What I am saying is that i build a contraption with two
male 110 volt plugs going into a female 220 volt female receptacle... i plug
each male 110 volt plug into a seperate 110 volt female receptacle tp
produce a 220 volt female receptacle....and I have a generator and don't
care to fire it u[p ay -30 degrees celcius...thats why i ask tis all....just
looking for the theory of it all.... thanks....jim
I guess what I don't understand is where is the electricity coming from
that you want to produce? In other words - if you already have 2 hot
120v legs, why do you need to create a 220 v outlet in the first
I think I _might_ understand what you are saying though - but I'm not
sure. In any event, to produce 240 v, you need not only 2 120v legs,
but two 120v legs which (someone please correct me on this) are 180
degrees out of phase.
In other words, lets say you had a 120v breaker, with a black wire
coming off of it.
Now, you hook another black wire to the same breaker, and you now have
two 120v leads, when each is measured to go ground.
Now, measure the voltage between the 2 black wires.... 0.
Man You are confusing me!
I think what he's saying is if there is 2 120V outlets coming from
different breakers.. can he make up an adapter the has 2 male 120V plugs
on it (to plug into each outlet) and a female 240v outlet on the other
end so he can plug his 240v equipment into....
It's not just "different" breakers. If you are looking for 240
volts, you need to find the hot wires of two outlets that are on
different breakers (circuits) and different legs (180 d. difference)
on your service panel.
One easy way of doing this is with a voltmeter and a two extension
cords coming from outlets that you know to be on different circuits.
If you measure the voltage between the two hot slots (the smaller slot
on the left when the ground is below - if your house is wired
properly), you should measure EITHER 120 V. or 240 V. (or something
close). If your house is balanced properly, the probability of
getting either voltage is 50-50 for any two circuit souces.
Keep in mind that that circuit breakers are going to be limited to
either 15 or 20 amps, while getting your 240 volts.
I don't recommend to do what you are doing. A big safety issue is
that the two breakers giving you your 240 Volts are not ganged, as are
other 240 volt circuits in your house. For example, if your dryer
circuit trips, BOTH legs are disconnected. This is to protect you
from killing yourself by disconnecting all possible hot sources to the
appliance. You have no such protection with your jury-rig system.
Sure it would. He could draw 20 amps at 220 volts from 2 different legs of
110v 20a. The electrons could care less, and the rating of the wires is in
amps. (Volts too for that matter but ordinary household romex is good to
Trouble would come in if he needed more than the 15 or 20 amps the wire
Of course this is just theoretical as the code does not permit this.
About the time I had mastered getting the toothpaste back in the tube, then
There is actually a commercial product that does this; so yes, it does work
(assuming your two 120v sources are oppposite legs)
If you used it temporarily, I suppose it might even be legal. Permanent use
would be improper because the breakers are not tied together.
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