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Questions about converting 220 to 110? Answered

I am working on a machine which uses two heaters and a cooler.   

Here is the electronics problem.  Right now I have a

15 amp 110v refrigerant compressor
and 2
15 amp 110v heaters on the machine.  

45 amps 110v.  That means I have to plug this machine into three different 110v plugs on different circuits.  There are cords going everywhere and the whole thing looks messy.  I am sure there is a way to plug this machine into 220 volts with one cord.  

The machine all together uses 45 amps 110v which is 4950 watts.  I found a transformer which should do what I want it to do.  


This transformer can supply up to 8000 watts from 220v.  This begs the question...How many amps can I draw from 220?  I believe it is 30 amps which is 6600 watts.  I think this would work because the machine draws 4950 watts all together.  But I need advice from the online electronics community.  Will this really work?



2 years ago

Yes most power to a house is 220 VAC with a split ground so that is where you get two 110 VAC lines out of phase with each other... So one room 110 outlet is 220 to another room outlet... In the US, wall outlets are limited to 15A per circuit.

On 220 you can wire and fuse for 30A, 50A or 75A

Most electric stoves are 30A, Hotubs go to 50A etc etc

14-2 gauge wire is limited to 15 amp breaker but if you have 12 -2 gauge wire you can use 20 amp breakers for wall outlets. A lot of builders skimp on the more expensive 12 gauge wire and put in 14 which then limits the outlets to 15 amp.

The electrical codes for home outlets are specified at no more then 15 A
in Chicago suburbs and Reno where the max outlet height is also specified.
Although with the recent increase of city flooding

that height is going through reevaluation !

That's interesting. I wonder if my state is different. I have a 200 amp main box and all the outlet breakers in it are 20 amp. There is not a 15 in the box. Then I have a secondary 100 amp main and all the breakers in that are 20 amp also.

Do you know what the reason is for setting the 15 amp outlet limit?

A few years ago in a friends house I replaced an ancient fuse box with a new breaker box and ran some new wiring. We rewired everything that was practical to do. I used 20 amp breakers and 12 /2 wire. It was all inspected by the electrical inspector and he had no problems with it. He did have us put in a better ground and a few other minor things but he was happy with the box.

Don't know how or why a code book came about.

When a city inspector has to bless an installation, you wire it according to the book. However the rules here do not, prevent a bigger gauge like a 12 instead of a 16, so after inspections are successfully completed and an occupancy permit is issued then one could change the 15A breakers to 20A ones or whatever.

Good idea!
Can I put the remaining 110 in the freezer for later use?

Just asking because of all the blondes out there...
Was told a blonde puts the hot water from boiling potatoes in the freezer - you never know when you need boiling water and in the freezer it stays fresh!

I hate to say it but it almost sounds like that is what this machine does.

Do you actually have a spare 220 volt circuit? And if you do, how big are the breakers attached to it? Probably the next question should be how big are the conductors of this 220 V circuit, and is one of those conductors a neutral wire?

I mean if you have a big fat neutral wire, then I am guessing you could just re-wire your 220V outlet into two 110 V outlets.

Of course you should draw a diagram of this first, and calculate the current through each wire, and through each breaker.

I have heard that you can turn 220 into 110 by separating the legs but I have also heard that it is illegal to do this because there is uneven load on each leg and this causes problems with your household wiring.

I looked at the breaker. I could not tell how many amps it is. Do you know if there is an average amperage for 220 volts?

Nothing Illegal about it. That is what your main breaker box does. The lines coming in from the power company are 220. Your box splits them and makes 110 for outlets and household current.

Most houses have a 100 amp or 200 AMP service. 200 is more common for newer houses or houses with electric heat.

The simplest solution to your problem would be to add an extra breaker to your box (provided it has room and can handle it) with a 40 or 50 amp breaker. A stove is usually 40. Then get a cable and run it from there (and it will be a heavy cable) to the location you want and install a secondary breaker box. Put in a series of 20 amp breakers and connect each one to a separate outlet. That way you will have each outlet on it's own breaker and a box specially set up to handle the load. You can put all the outlets next to each other. They don't have to be separated by a specific distance.

If your current main box can't handle the load then you might need to upgrade your service and box. You could actually reverse the procedure I mentioned. Have them put in a new box with a heavier service and patch in your existing one by running a cable to it from the new box. Then you don't have to do any rewiring or replace the existing box.

Thank you for your reply. It looks like I don't need a 220 to 110 transformer. Let me paraphrase what you said. That will help me to understand it better. I know I would need an electrician to do this.

-I get 50 amp 220 breaker
-I run a 220v cable from the breaker to the machine
-I have another breaker box in the machine in which I will split the 220 into probably four 110v circuits.

50 amps of 220 is 11,000 watts. The machine draws 5000 watts at most so I could use a 30 amp 220v breaker which would provide a max of 6600 watts.

Basically yes. However there are a few different ways it can be done and those will depend on your existing hookup. If your current box can handle the addition then its a simple add into the existing system. What I am guessing they will suggest is to add a main power distribution box. This is a new box that the power coming from the meter will go to. The box will have 2 100 amp breakers. One will have cables that connect to your existing main box and the second breaker will connect to a new main box wherever you want to put it. That way the original box will remain undisturbed and you just put a new one where you need it.

I was kind of expecting the current rating for the breakers to be printed on the breakers themselves, so that these numbers are visible just by opening the door on the breaker box and looking inside.

For example, on this page,
Step 5 shows a close-up of four 220V circuit breakers in a breaker box.

Regarding your question about an average-sized 220V circuit, i.e. is there an average-sized 220V circuit? The answer to that question sort of depends on what load that circuit was intended to supply. Was the circuit intended for an oven? A clothes dryer? A water heater? An air conditioner?

Interestingly, there are a bunch of different shaped 220V receptacles for these different loads. So the shape of the receptacle may give some clues as to the current available from the outlet. Conveniently, the Wikipedia article on "NEMA connector"
has a graphic showing several of these outlet shapes.

I am guessing these are the same shapes used in your locale of "Eugene" (Oregon?)

Also worth mentioning, is the presence or absence of a neutral wire, at that outlet. Some 220V loads do not actually need a neutral conductor, so the wires that go from the breaker box to that outlet might NOT include a neutral; i.e. the wires going to the outlet are just L1, L2, and ground.

A neutral conductor is necessary for 220V loads that are unbalanced; i.e. for an unbalanced load, a significant non-zero current will flow through the neutral wire, so there has to be a big fat neutral wire as part of the circuit, for to carry that current.

This would be easier to, um, picture if you, uh, drew yourself a circuit diagram of this. I might have already suggested this. Or maybe I should draw a diagram of this circuit, the way I am imagining it, and I could do that upon request.

are the two heaters on together or separately?

On 220 (240) V you will still need over 20 amps and that is without calculating any losses for the transformer.

IMHO the best option would be to add a heavy duty cable from your existing fusebox to a new one where the power is used.
This way you seperate the powers, have additional fuses right where they are needed (please consider a safety switch as well) and no problems with the distibution of hese power levels.