How to get 240VAC in your kitchen without rewiring...

A cut and paste from another thread because people seem to miss this stuff.

There are 2 ways to get 240VAC in a kitchen without rewiring anything.

1) Plug the unit into the stove receptacle. This will require replacing the stove breaker with a GCFI breaker at the very least. Or you can wire up a small 2 breaker panel with a GFCI in it and a plug that plugs into the stove receptacle.

2) Find 2 120VAC plugs that are wired to opposite sides of the 240VAC supply. Build an adapter cord to go from 2 120VAC plugs to the 240VAC receptacle that the unit requires. The breakers on both 120VAC circuits will need to be replaced with GFCI breakers or wire in a small 2 breaker panel and put a 2 pole GCFI in it. This circuit will function exactly like a normal 15A 240VAC circuit would, only the 2 hot wires come from 2 different plugs rather than 1.

One can pull 240VAC x 15A = 3600 watts from 2 standard 120VAC plugs wired to opposite sides of the 240VAC supply.

If the garage has a panel in it, it is very easy to put a device box on the panel with a simple connector, pop in a GFCI breaker and install a receptacle in the device box.

If the garage has plugs on multiple breakers, it is possible that they may be on opposite sides of the 240V supply, just like in a kitchen.

You can also get 240VAC power from a dryer plug.

I hope this helps.

option 1 only works if you have an electric oven/range. and it isn't a built-in.

option 2 is a major code violation and a practical safety hazard. one leg of the circuit could trip one breaker and not the other. unplug the cord from the receptacle that tripped and you will have 120v on the male end.

if you want to do this, check out this product (only good up to 20 amps, doesn't work on gfci receptacles):

http://www.quick220.com/-A220-20D.html

itsnotrequired said:

option 1 only works if you have an electric oven/range. and it isn't a built-in.

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If the range is built in, you wire in a junction box and put a receptacle in it. Or if there is room, you wire in a panel and put the GFCI in the panel and a plug underneath it.

option 2 is a major code violation and a practical safety hazard. one leg of the circuit could trip one breaker and not the other. unplug the cord from the receptacle that tripped and you will have 120v on the male end.

Click to expand...

I haven't tested it, but I'm pretty sure that the GFCI will trip if you disconnect one of the supply legs.

And GFCIs isolate the load side if they are miswired and I'm thinking that a missing supply line on a 2 pole GFCI would constitute a mis wiring. Thus there would be no supply voltage coming back through the disconnected side supply side of the GCFI.

FWIW, 2 pole GFCIs trip both sides if there is an overload. I'm assuming that one would put a GFCI in a small panel that the 2 120VAC cords connected to if you did this.

This needs to be tested before it is relied on.

Duplicate post

Another way to get 240VAC in the kitchen or garage is to change the breaker and receptacle(s) on a 120VAC 15A (or 20A) circuit.

Residential wire is rated by current and the same wire is used to carry 120 or 240VAC. Any 120VAC 15A receptacle can be rewired to be a 240VAC receptacle by replacing the 120VAC receptacle with a 240VAC 15A receptacle. You'll have to do this for all the receptacles on that circuit and make sure that there are no lights or other loads tied into the circuit.

To complete the change you need to change the single pole breaker in the breaker box with a 15A double pole (GCFI) breaker.

Modern electrical code puts a big limit on how many receptacles one can place on a single breaker in a kitchen. In some cases each receptacle is going to get a breaker. If a breaker serves more than a single receptacle, it might have to be a 20 circuit. Code is designed so that the user can plug in high power appliances like a tea pot, toaster and microwave and not be tripping breakers. That means that each of these appliances pretty much need their own breaker, or at least any 2 of them together would draw more than a single 15A breaker can provide.

Desperate times call for desperate measures ! Where there is a will, there is a way. If you can find a 120VAC receptacle that is served by its own breaker, it is very easy to convert it to 240VAC. And there are several options if that circuit has more than one receptacle on it.

I spent the last 3 years on and off rewiring our house due to renovation, which included a full kitchen and the addition of a lot of new circuits. We pulled a lot of wire through existing walls in the process. We just completed completely replacing the main panel in the garage and 2 large panels in the basement of the house before Christmas.

I'll be pulling wire for 240VAC/120VAC 20A circuits into our kitchen and into my brewing area this weekend. If the basement ceiling is open under the kitchen or can easily be opened, it isn't very difficult to fish in new wire for a new circuit. The easiest place to put the receptacle is hidden in a cupboard. The nice things about cupboards is that you can drill down through the bottom of the cupboard and through the floor to the basement. It is much easier to put a receptacle in a cupboard than in a wall.

It is also much easier fishing wire through floor joists than walls.

Another easy wiring situation is putting a receptacle in a wall in a bungalow if you have access to the attic above and if you have a plenum to feed a wire down from the attic to the electrical panel in the basement. The plenum part is easy... if you dig under the insulation in the attic, you'll find the header 2x4 plate on the top of the wall. If you drill through the header you can easily feed wire down through the wall. Getting the wire into the basement is easy too, if you have decently high baseboards. Remove the baseboard and then cut a small hole in the drywall. Get a snake drill or a long auger boring bit and drill down through the bottom wall plate into the basement. Fish the wire through from the top and then cover up the hole with the baseboard.

If you don't feel comfortable doing a wiring job, you can cut your costs significantly by doing all the prep work before bringing in the professional. The tying in of a circuit only takes an hour. The labor of wiring is pulling cables, securing them, mounting device boxes and purchasing materials. If you have the wire pulled and secured from the panel to the device box and you have the device box mounted and the panel opened up, it takes very little time for an electrician to finish the job.

Where electrical jobs get expensive is when the electrician comes in and nothing has been done. He has to find the route, get the material, pull the wire, secure the wire, mount the device box, open the panel, source the new breaker, install it and then tie everything in.

If you fail to have a licensed electrician do the work your insurance company will not cover any damages caused by a wiring fault. Just sayin.....

rusty_tlc said:

If you fail to have a licensed electrician do the work your insurance company will not cover any damages caused by a wiring fault. Just sayin.....

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That is not true. Insurance companies don't get to absolve liability because people did stupid things. Accidents are stupid things. They can sue for negligence in extreme conditions, but it has to be just about criminal.

Our home policy not only covers liability on work I do, but also covers anyone who works on or in the house. Granted they are expected to have their own insurance, but if it falls back on me, I'm covered. Check your policy.

It is pretty hard to do damage with wiring. If you want to do damage to a house, take up plumbing, where a leak will cause flood damage and propane soldering torches start an alarming number of house on fire. The biggest thing to get right with electrical is that everything in the circuit has to be rated for more current than the breaker. The breaker needs to be the weakest link. It trips before anything else gets overloaded. Get that right and tie in all your grounds and you'll be fine.

While we are talking about liability and wiring safety, any electrical junction box in a wet area should be metal and the box should be tied to earth (bonded) and the supply should be GFCI protected. Period, end of story. I don't get how some electric kettles use PLASTIC boxes over the element connections. Especially when the side of the kettle is going to be 210F or so.

Using two 120 volt circuits to run a 240 volt load is dangerous. Don't do it!

Riiiight cause insurance companies never mind paying claims. Liability for negligence aside, do you really want to deal with the fight or the inconvenience?

beermanpete said:

Using two 120 volt circuits to run a 240 volt load is dangerous. Don't do it!

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No it isn't. It is exactly the same as using a 120/240V receptacle circuit, like a stove or dryer, except there are 2 neutrals, which tie to the same bus in the panel and the 2 hots run in different cables. In big 3 phase wiring, each of the conductors is a separate cable !

rusty_tlc said:

Riiiight cause insurance companies never mind paying claims. Liability for negligence aside, do you really want to deal with the fight or the inconvenience?

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What fight or inconvenience ? If you are worried and if your jurisdiction allows it, pull a homeowners electrical permit, wire it up and get it officially inspected. That is what I did with our reno. Or, wire it up and get a professional in to inspect it. If you find the right guy, he may even teach you some stuff.

Well the way I am doing it is I got a 50 amp gfci breaker for my box. I will have a like 1' run from the box to a plug then I have a 30' 50 amp extension cord. Cellar stairs are right by the breaker box and the door to the cellar is in the kitchen. Extension cord up the stairs into the kitchen.

Not ideal but until I get the detached garage wiring upgraded and water and sewer in it I have to adapt.

Only hurdle left to figure out is ventilation for doing 1bbl batches in my kitchen.

brewman ! said:

No it isn't. It is exactly the same as using a 120/240V receptacle circuit, like a stove or dryer, except there are 2 neutrals, which tie to the same bus in the panel and the 2 hots run in different cables. In big 3 phase wiring, each of the conductors is a separate cable !

Click to expand...

Yes but the method you advise will not open both lines because the breakers are not ganged together. If one opens the other will likely stay on and continue to provide power to circuit. This could create a dangerous condition, especially for people who are not familiar with electric circuits and are therfore unaware of the danger.

Very dangerous to split receptacles. Better to use 2 120V elements.

brewman ! said:

What fight or inconvenience ? If you are worried and if your jurisdiction allows it, pull a homeowners electrical permit, wire it up and get it officially inspected. That is what I did with our reno. Or, wire it up and get a professional in to inspect it. If you find the right guy, he may even teach you some stuff.

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The fight and inconvenience of getting the insurance company to pay up on a claim.

Typically adding and outlet does not require permits. Renovations are a whole other thing.

A professional is not going to inspect work for free, minimum charges would be one hour plus travel time. Depending on how far the outlet is from the panel the labor may not run more than one or two hours. In my experience guys who work construction do not appreciate "homeowner" work, I doubt they would take time to teach me some stuff.

As an aside: I grew up with two electricians for fathers, I started pulling wire etc. at an early age. Because I am not licensed I paid an electrician to install the 220V outlet in my garage. In my opinion the potential liability of doing the work myself was not worth the savings so I hired a licensed electrician.

Some pictures for you guys...

A small panel that I use on my work bench for testing brewing stuff. 2 pole 240VAC 20A, GFCI protected. It isn't presently hooked up to anything. I'm going to put a cord with a stove plug on it and a 20A 240VAC receptacle for brewing at my friends' house. This is the panel that should be used with a dual 120VAC feed. Notice that the GFCI breakers are tied together. If one trips they both trip.



This was the old 100A panel in my garage. The black cable to the right is unconnected. It runs to the mechanical room in my house.




This is the new 200A panel in my garage. Each of the cables coming out the bottom carry 100A to a panel in the house and have their own 100A breaker in the garage panel. The cables are extra long because they need to be adjusted elsewhere.

Myself and an electrician (ex lineman) hot swapped this panel in place because the electrical utility wanted like $1500 to turn off the power leading into the box. I would never hot swap a box myself, but he works on live power stuff all the time and has the special gloves, insulated tools, training, etc. He owed me a favor so wasn't that expensive.



This is a 240VAC 2 pole GFCI breaker. The load neutral ties into the breaker, which has its own neutral that gets tied into the neutral bus. If you mess up your neutrals and have another neutral returning current for your circuit, it trips immediately ! Expensive boogers. Note that GFCIs "fail safe" if you mis wire them. They disconnect power from the load if the feed isn't proper.





The new panels in my house. Used to be a small single 100A panel with a 70A sub panel hanging off it. Now each panel has its own 100A feed from the garage.

The house has a steam shower (50A) an induction cook top (40A), dual air conditioners (30A each), a double oven (40A), an electric dryer (40A) and a jacuzzi tub (30A). Plus all the lighting and plug circuits. Plus the welder (50A), air compressor (20A), plasma cutter (40A) and electric heater circuits (50A) in the garage. To say the 100A electrical service was overloaded was an understatement. 200A is still pretty light, but it costs a fortune to get a larger service.

Luckily I knew about this problem when we bought the house and had a plan to deal with it.

The kicker was the reno replaced a gas cook top with an induction cook top and it needed a 40A breaker. Plus the extra lighting circuits. Both old boxes were full and overloaded before we started the reno project.



I hired a guy I knew (electrician) to help me with the panel work because we had to do a hot swap in the garage and I didn't want the house unpowered for long while it was being done. I did all the other electrical work in the house myself, including changing every receptacle and switch because of a decor color change, adding a bunch of lights, rewiring plugs in the kitchen and wiring the new island. The old island didn't have a single receptacle.

I did about half of the panel work, he did the other half. Took us 3 days to replace the garage and house panels and do some other misc electrical stuff. I had to go back and do some cleanup work on the house panels after he was gone. We were still pulling new circuits into these panels when this picture was taken.

The old panels were Federal Pioneer. Electricians call them match boxes because the breakers are notorious for overheating and not tripping. My insurance company should be paying my premium for me getting them upgraded.

I like doing wiring because it is clean, fairly easy work. I don't mean to brag, but I literally saved thousands and thousands of dollars doing the electrical in our house. I urge people to consider doing at least some of their electrical work themselves. It is a great skill to learn too.

Some advice... electrical panels are relatively inexpensive. Breakers are what costs as far as panel hardware goes. If you ever spec a new panel or replace an old one, be sure to size it 30-40% larger than you presently need. Everyone adds circuits to a house. Nobody removes them. Plan ahead for that.

It is a not very straight forward task to replace an existing electrical panel with a larger one when you outgrow it. Electrical wire is cut pretty much to length at the panel. It is not like there is 3 or 4 feet of slack wire somewhere in the house when you decide to reposition your replacement panel.

One other piece of advice... never complain about electrical code. Electrical code came about because someone got hurt or someone's house burnt down. Wanna know what life would be like without electrical code ? Go look at the post and line wiring in an old house. Scary !

If an electrician tells you he doesn't want his work inspected, don't hire him. Don't take shortcuts on material or technique when wiring something. Make sure everything meets code. It is there for a reason. Don't ever think you can get away with something because it is hidden behind a wall.

Another piece of advice, if you are wiring something tricky and you have questions, call an electrical inspector. They've probably seen it before and will have input on how they would like to see it done. They also know who the good electricians are.

brewman ! said:

If the range is built in, you wire in a junction box and put a receptacle in it. Or if there is room, you wire in a panel and put the GFCI in the panel and a plug underneath it.

I haven't tested it, but I'm pretty sure that the GFCI will trip if you disconnect one of the supply legs.

And GFCIs isolate the load side if they are miswired and I'm thinking that a missing supply line on a 2 pole GFCI would constitute a mis wiring. Thus there would be no supply voltage coming back through the disconnected side supply side of the GCFI.

FWIW, 2 pole GFCIs trip both sides if there is an overload. I'm assuming that one would put a GFCI in a small panel that the 2 120VAC cords connected to if you did this.

This needs to be tested before it is relied on.

Click to expand...

Minor pedantry: GFCIs themselves do not trip on overload. They trip on imbalance between the current in the hot and neutral legs. A GFCI maybe combined with a breaker that will trip on overload, but e.g. GFCI outlets do not have a breaker in them.

itsnotrequired said:

option 1 only works if you have an electric oven/range. and it isn't a built-in.



http://www.quick220.com/-A220-20D.html

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I dont think thats a completely acurate statement.
A lot of homes have the hookups for both and average joe homeowner might not be aware that theres an unused 50a plug behind his or her gas stove in some cases..

couldnt a phase generator be used here too to create 240v or does that only work when more than one phase is already present? I realize its not practical but hey a that's a relative term to a lot of folks here..

This post will, I hope, prevent someone from being as stupid as I was. I bought a summer house with no garage and so undertook the building of one with an apartment above it. In the course of figuring out what we would have to do to merge the old and new electrical systems I started tracing out the system in the old house and noticed that the row of duplex outlets in the kitchen were wired with one outlet connected to one phase and the other to the other. I'd never seen that before and puzzled as to why it was done that way.

A year later I am standing in my new shop looking at the neat new row of 120V and 240 V outlets (I had the electrician put in several for future purchases of 240 V tools) and it hit me. If I had been smart enough to tell the guy to pull 12/3 to the 240V outlets instead of 12/2 I would have the option of 240V or 120V outlets in those boxes I told him to wire for 240. But, alas, I told him they were to be 240V outlets and he pulled 12/2. Of course it's irreversible at this point (except at huge expense and trouble).

Relevant to the original question I can, in the kitchen of the original house, easily obtain 240 at one of those boxes by replacing the 120V outlets with an appropriate 240 V outlet.

The message here is that if you want the option of 120 or 240 in new construction pull 3 conductor (plus neutral) to that box even though you may never use it. There are, of course, implications as to what you do in the panel with respect to breakers.

brewman ! said:

Myself and an electrician (ex lineman) hot swapped this panel in place because the electrical utility wanted like $1500 to turn off the power leading into the box. I would never hot swap a box myself, but he works on live power stuff all the time and has the special gloves, insulated tools, training, etc. He owed me a favor so wasn't that expensive.

I don't mean to brag, but I literally saved thousands and thousands of dollars doing the electrical in our house. I urge people to consider doing at least some of their electrical work themselves. It is a great skill to learn too.

Click to expand...

I've done some of my own electrical work including some 3 phase for my business, and quite a bit for various homes I've owned and agree that its a good thing to learn/know about. I also agree that you can save a lot of cash by doing some of your own work.
I'm not a professional, but the pictures look like a job well done, at least what I can see from here.
Two things that weren't mentioned though, could be problems.
The "hot box" swap obviously didn't include a permit or an inspection.
Or maybe you got an inspection sticker to go on the box?
If you ever go to sell your house, any home inspector is going to notice if your electrical panels have been installed with out an inspector's sticker and signature. That's the way they do it around here anyway, I don't know what they do in your area.
Another issue it the service cable from the pole/transformer to your house. If your original service was an old 100 amp panel, one could presume the cable from the pole is equally old and sized for that level of electrical service?
Something to think about when doing this kind of work is the possible "exposure" both financially and to you or others personal safety.
If there is a fire because of electrical problems and you face a loss or someone is injured or killed will the $1500 you saved be considered a good investment? What about criminal proceedings for an injury caused by gross negligence (failure to get a permit/inspection would be proof of that) what if a fire fighter is injured or killed.
If you ever sell the house, and a the un-inspected panels are discovered, you will probably pay more than $1500 to get it sorted out and may face a fine for doing the work without proper permits.
I have an old house and an old service panel and consider myself fully capable of doing a "hot box" swap, but I'm not going to do that. The downside is just not worth it. When I have the money to do it with all the proper permits and inspections it will get done. My circuit breakers are working fine, so its not a priority at the moment.
My final thought is that anyone out there considering doing their own electrical upgrades can make that decision themselves, but at the same time you should consider your total financial risk and the possible risk to others.

ajdelange said:

This post will, I hope, prevent someone from being as stupid as I was. I bought a summer house with no garage and so undertook the building of one with an apartment above it. In the course of figuring out what we would have to do to merge the old and new electrical systems I started tracing out the system in the old house and noticed that the row of duplex outlets in the kitchen were wired with one outlet connected to one phase and the other to the other. I'd never seen that before and puzzled as to why it was done that way.

A year later I am standing in my new shop looking at the neat new row of 120V and 240 V outlets (I had the electrician put in several for future purchases of 240 V tools) in my new shop and it hit me. If I had been smart enough to tell the guy to pull 12/3 to the 240V outlets instead of 12/2 I would have the option of 240V or 120V outlets in those boxes I told him to wire for 240. But, alas, I told him they were to be 240V outlets and he pulled 12/2. Of course it's irreversible at this point (except at huge expense and trouble).

Relevant to the original question I can, in the kitchen of the original house, easily obtain 240 at one of those boxes by replacing the 120V outlets with an appropriate 240 V outlet.

The message here is that if you want the option of 120 or 240 in new construction pull 3 conductor (plus neutral) to that box even though you may never use it. There are, of course, implications as to what you do in the panel with respect to breakers.

Click to expand...

This would completely depend on the whether GFCI protection (that meets code) is needed on the 240v line right?

12/2 has 2 conductors plus a ground wire (3 total conductors with ground) as far as I remember and can easily be used for either 240v (without a gfci like used in a dryer wiring configuration) or 120v ... the 12/3 would still have the advantage to either be used for a 240v gfci outlet or a 120v gfci outlet..

madscientist451 said:

I've done some of my own electrical work including some 3 phase for my business, and quite a bit for various homes I've owned and agree that its a good thing to learn/know about. I also agree that you can save a lot of cash by doing some of your own work.
I'm not a professional, but the pictures look like a job well done, at least what I can see from here.
Two things that weren't mentioned though, could be problems.
The "hot box" swap obviously didn't include a permit or an inspection.
Or maybe you got an inspection sticker to go on the box?
If you ever go to sell your house, any home inspector is going to notice if your electrical panels have been installed with out an inspector's sticker and signature. That's the way they do it around here anyway, I don't know what they do in your area.
Another issue it the service cable from the pole/transformer to your house. If your original service was an old 100 amp panel, one could presume the cable from the pole is equally old and sized for that level of electrical service?
Something to think about when doing this kind of work is the possible "exposure" both financially and to you or others personal safety.
If there is a fire because of electrical problems and you face a loss or someone is injured or killed will the $1500 you saved be considered a good investment? What about criminal proceedings for an injury caused by gross negligence (failure to get a permit/inspection would be proof of that) what if a fire fighter is injured or killed.
If you ever sell the house, and a the un-inspected panels are discovered, you will probably pay more than $1500 to get it sorted out and may face a fine for doing the work without proper permits.
I have an old house and an old service panel and consider myself fully capable of doing a "hot box" swap, but I'm not going to do that. The downside is just not worth it. When I have the money to do it with all the proper permits and inspections it will get done. My circuit breakers are working fine, so its not a priority at the moment.
My final thought is that anyone out there considering doing their own electrical upgrades can make that decision themselves, but at the same time you should consider your total financial risk and the possible risk to others.

Click to expand...

theres another thread recently where one of the questions you bring to light was asked... and another member here posted he had 800 amps worth of breakers tied to a 200 amp service since theres no restriction to the amount of devices on that service as long as the mains breakers meet the same rating as the wiring feeding it power which is the questionable thing here...

I cannot figure why you need 240V instead of running 2x 120V from different circuits. Install two separate coils.

augiedoggy said:

This would completely depend on the whether GFCI protection (that meets code) is needed on the 240v line right?

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If you run two phases, neutral and earth you have complete flexibility with regard to GFCI.

You can have no GFCI if none is required
You can install GFCI in the panel
You can install GFCI outlets as is conventionally done (120V) by simply not using the red wire.
You can install 240V GFCI outlets
You can use an in-cord GFCI at the outlet.

augiedoggy said:

12/2 has 2 conductors plus a ground wire (3 total conductors with ground) as far as I remember and can easily be used for either 240v (without a gfci like used in a dryer wiring configuration)

Click to expand...

You could still have GFCI in a grandfathered earth as neutral arrangement but you'd have to isolate the 120V circuits in the dryer and power them with a 2:1 stepdown transformer.

augiedoggy said:

theres another thread recently where one of the questions you bring to light was asked... and another member here posted he had 800 amps worth of breakers tied to a 200 amp service since theres no restriction to the amount of devices on that service as long as the mains breakers meet the same rating as the wiring feeding it power which is the questionable thing here...

Click to expand...

The point I was making wasn't about how many breakers were installed.
The OP's original service panel was an older, 100 amp device. Should the wire from the pole/transformer be replaced when upgrading from a 100 amp panel to a 200 amp? Of course that depends on what is actually there and how old it is. That's why the power company and an inspector should be involved when increasing the load you are putting on the existing wire.

Here in PA, violations to the building/electrical code can result in an order to vacate the building until the problem is corrected. Usually, if a violation is found, the property owner is granted time to correct the problem, depending on what it is.
What the OP described doing (hot swap of a service panel without permits or inspections) would be considered an outright violation of law here in PA, but I don't know if that would be true in his area.

dyqik said:

Minor pedantry: GFCIs themselves do not trip on overload. They trip on imbalance between the current in the hot and neutral legs. A GFCI maybe combined with a breaker that will trip on overload, but e.g. GFCI outlets do not have a breaker in them.

Click to expand...

A GFCI breaker trips on current overload just like a regular breaker. If they didn't, you'd have to use a GFCI in combination with a regular breaker to prevent circuit current overload.

Here is the circuit that I am proposing.

ajdelange said:

This post will, I hope, prevent someone from being as stupid as I was. I bought a summer house with no garage and so undertook the building of one with an apartment above it. In the course of figuring out what we would have to do to merge the old and new electrical systems I started tracing out the system in the old house and noticed that the row of duplex outlets in the kitchen were wired with one outlet connected to one phase and the other to the other. I'd never seen that before and puzzled as to why it was done that way.

A year later I am standing in my new shop looking at the neat new row of 120V and 240 V outlets (I had the electrician put in several for future purchases of 240 V tools) and it hit me. If I had been smart enough to tell the guy to pull 12/3 to the 240V outlets instead of 12/2 I would have the option of 240V or 120V outlets in those boxes I told him to wire for 240. But, alas, I told him they were to be 240V outlets and he pulled 12/2. Of course it's irreversible at this point (except at huge expense and trouble).

Relevant to the original question I can, in the kitchen of the original house, easily obtain 240 at one of those boxes by replacing the 120V outlets with an appropriate 240 V outlet.

The message here is that if you want the option of 120 or 240 in new construction pull 3 conductor (plus neutral) to that box even though you may never use it. There are, of course, implications as to what you do in the panel with respect to breakers.

Click to expand...

Most people don't understand how a 14/3 or 12/3 circuit actually works. The reasoning behind using 1 neutral wire for 2 15A circuits is that the 2 hots are supposed to be wired to opposite "phases" of the 240V supply. When this happens, with equal loads on the 120VAC circuits the neutral currents are out of phase and actually cancel each other. With equal loads on the 120VAC circuits, there is actually zero current in the neutral. Worst case, with one 120VAC circuit maxed out at 15A and the other circuit unused, the neutral carries 15A.

HOWEVER, if the 14/3 circuit is miswired at the breaker box and both 120VAC circuits are on the same phase, the neutral wire carries 2x the rated current worse case. It is VERY easy to check this with a multimeter. The 2 hots on every 14/3 circuit should have 240VAC across them. If they are wired wrong, they will have 0V across them. You just open up the breaker box and trace every 14/3 circuit to the breakers and then measure the voltage across the 2 breaker wire connect screws. Takes 10 minutes to do a box. Some electricians don't understand this.

For receptacles in our kitchen in the areas for high loads, ie toaster, coffee pot, tea pot, toaster oven, etc, I pulled 14/3 to each outlet box, then split the receptacle, wiring each receptacle on its own breaker. The extra cost involved is the difference between running 14/2 and 14/2 and 1 extra breaker. Small price to pay for never having to worry about tripping a breaker when running big load appliances.

madscientist451 said:

I've done some of my own electrical work including some 3 phase for my business, and quite a bit for various homes I've owned and agree that its a good thing to learn/know about. I also agree that you can save a lot of cash by doing some of your own work.
I'm not a professional, but the pictures look like a job well done, at least what I can see from here.
Two things that weren't mentioned though, could be problems.
The "hot box" swap obviously didn't include a permit or an inspection.
Or maybe you got an inspection sticker to go on the box?

Click to expand...

I have an open homeowner electrical permit on the house at the moment. I was waiting to complete this work to close off the permit. And the basement was developed prior to me buying the house and that work wasn't done under a permit at all. This is not uncommon. So when everything is done, I'll call for an inspection and everything will be completed properly.

I had an inspection done on the renovation wiring prior to closing it up. It passed with flying colors. I also showed the inspector a few things they missed in the new house inspection and how I fixed them.

If you ever go to sell your house, any home inspector is going to notice if your electrical panels have been installed with out an inspector's sticker and signature. That's the way they do it around here anyway, I don't know what they do in your area.

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They will be inspected by then. FWIW, I discussed the installation of the second panel with the building inspectors prior to doing it.

Another issue it the service cable from the pole/transformer to your house. If your original service was an old 100 amp panel, one could presume the cable from the pole is equally old and sized for that level of electrical service?

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None of this stuff was old. The house was built in 2008. The builder did a poor job of specing the service.

The overhead line feed is the same for 100A and 200A services in our area. The conductors from the garage panel to the overhead line are good for 200A. But the meter is only rated for 100A. We'll update that in the near future. Technically we are in violation. Practically I'm not worried about it. The biggest issue with running the wrong meter is that it doesn't measure accurately outside its nameplate rating, ie 100A in this case.

Something to think about when doing this kind of work is the possible "exposure" both financially and to you or others personal safety.
If there is a fire because of electrical problems and you face a loss or someone is injured or killed will the $1500 you saved be considered a good investment? What about criminal proceedings for an injury caused by gross negligence (failure to get a permit/inspection would be proof of that) what if a fire fighter is injured or killed.

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Nice FUD attack. Fear, Uncertainty and Doubt. Did you do any research prior to posting that ? Can you point to any cases where this has actually occurred or is it folklore ?

How big of a wiring mistake do you think it would take to cause a fire or cause someone to be killed or injured ?

If you ever sell the house, and a the un-inspected panels are discovered, you will probably pay more than $1500 to get it sorted out and may face a fine for doing the work without proper permits.

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There is no fine for doing work outside of a permit. Some "professionals" do it all the time. The basement development in our house was done without a permit. It is possible to get post work inspections done. They cost a bit more, but nothing outrageous. It takes longer for the inspector to have a look at things. They'll ask you to open up various outlet boxes and switches for the inspection.

I have an old house and an old service panel and consider myself fully capable of doing a "hot box" swap, but I'm not going to do that.

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Unless you have been trained in HV electricity and have experience doing line work and the proper tools and gear, you ARE NOT capable of safely doing a hot panel swap. DO NOT DO IT. There is no breaker between the electrical line and the panel. The only breaker on the system is what the power company has on the line and that isn't going to care about the 40A burning your arms and going through your heart. Electrical burns are a very real and serious thing.

I shouldn't have mentioned doing the hot panel swap. I didn't want to lie and say that I did the work all myself, so I shared the big reason why I was using outside help.

The downside is just not worth it.

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To you.

When I have the money to do it with all the proper permits and inspections it will get done.

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The inspection process is the same whether the home owner does it or a contractor. I've seen contractors take short cuts. Worst part about that is they tend to hide them.

My final thought is that anyone out there considering doing their own electrical upgrades can make that decision themselves, but at the same time you should consider your total financial risk and the possible risk to others.

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If you don't take short cuts, these are both zero.

augiedoggy said:

This would completely depend on the whether GFCI protection (that meets code) is needed on the 240v line right?

12/2 has 2 conductors plus a ground wire (3 total conductors with ground) as far as I remember and can easily be used for either 240v (without a gfci like used in a dryer wiring configuration) or 120v ... the 12/3 would still have the advantage to either be used for a 240v gfci outlet or a 120v gfci outlet..

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You can use a 2 pole GFCI to protect a split phase circuit if it also supplies 240VAC. It will still protect each of the 120VAC circuits. The only drawback is that if you trip one of the 120VAC circuits, it is going to trip the breaker for the other circuit too.

brewman ! said:

I have an open homeowner electrical permit on the house at the moment.

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Jurisdiction? Please.

ajdelange said:

Jurisdiction? Please.

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Why does it matter ?

Redlantern said:

I cannot figure why you need 240V instead of running 2x 120V from different circuits. Install two separate coils.

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Some people want to use 240VAC induction heaters.

brewman ! said:

You just open up the breaker box and trace every 14/3 circuit to the breakers and then measure the voltage across the 2 breaker wire connect screws.Takes 10 minutes to do a box.

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Less than that if you just stick your VM probes into the two narrow (hot) slots in in the two outlets in the box in question. Should read 240 if wired properly, 0 OW. No need to remove the panel cover.

brewman ! said:

For receptacles in our kitchen in the areas for high loads, ie toaster, coffee pot, tea pot, toaster oven, etc, I pulled 14/3 to each outlet box, then split the receptacle, wiring each receptacle on its own breaker.

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So now I know of two houses that have this. Anyone else?

brewman ! said:

Another way to get 240VAC in the kitchen or garage is to change the breaker and receptacle(s) on a 120VAC 15A (or 20A) circuit.

Residential wire is rated by current and the same wire is used to carry 120 or 240VAC. Any 120VAC 15A receptacle can be rewired to be a 240VAC receptacle by replacing the 120VAC receptacle with a 240VAC 15A receptacle. You'll have to do this for all the receptacles on that circuit and make sure that there are no lights or other loads tied into the circuit.

To complete the change you need to change the single pole breaker in the breaker box with a 15A double pole (GCFI) breaker.

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this is a code violation. the old white neutral from the previous installation will now be a hot conductor. hots cannot be white in this application. it will work but not meet code. this also really only works if it is an isolated receptacle on a single circuit, otherwise every other receptacle on the circuit will be 240v as well.

brewman ! said:

Here is the circuit that I am proposing.

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i don't believe that will work if the 120v receptacles already have gfci protection (like in a kitchen). the return neutral current will not be balanced between the two circuits.

brewman ! said:

Why does it matter ?

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Obviously, because not all jurisdictions allow this.

itsnotrequired said:

this is a code violation. the old white neutral from the previous installation will now be a hot conductor. hots cannot be white in this application.

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No worry there. A white conductor is easily converted to ungrounded status simply by wrapping a little black or red tape around it at each end. But here he isn't in a box at all. He is just plugging into a couple of outlets and running to a box with a breaker and 240 V outlet in it. Probably won't get UL approval but who cares?

itsnotrequired said:

i don't believe that will work if the 120v receptacles already have gfci protection (like in a kitchen). the return neutral current will not be balanced between the two circuits.

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No, it won't. There is NO neutral current in those outlets to balance the phase currents and a GFCI will trip. The outlets he plugs into cannot be GFCI outlets.