Welding Tips and Tricks

220 volts from two 110 volt extension cords ?

Is this a crazy idea?

The 220 volt service comes in on 3 wire, one natural and two hots . Connecting from either of the hots and the neutral will give you 110 volts and connecting to the two hots give you 220 volts.

To balance the load on the service feed, the breaker panel alternates between the two service hot leads while connecting 110 breaker. That means, if I take a extension cord and a volt meter, plug into one outlet, it should not be hard to find a second outlet feed off the other hot leg which would give me 220 volts. By plugging a second extension cord into that outlet and using an adapter that would only connect to the hot leg of each extension cord and their grounds and wiring them to a 220 socket I should get a 15 amp 220 volt outlet.

Is this a dangerous idea? I know no building electrical code would OK it, but as a temporary connection for a welder supply it would be nice.

What do you think?

Mark

Ummmmmm...

Well that's interesting. I wouldn't do it. I'm no electrical expert but something seems wrong about that plan and in sure there is a good reason

But maybe someone thinks otherwise, doubtful but.
Is it not possible to get a 220 volt otherwise where you are?

I can do it. I would rather not, and I won't tell you how.

Shortly, it's possible, but not really a good idea.

Steve S

It sounds like it would work...for awhile...it sounds like it would be dangerous as well...not thinkin it would be a good idea

I'm a pretty "redneck" kind of guy when it comes to getting a solution to a problem, and I know how to do just that, but like the others, nope. Not at my house or anyone else's. Best to run a sub - panel and wire it correctly.

Technically it "works". There are several problems with it in actual practice though. The breakers for each hot leg will not bother trip at the same time in event of a fault. In a residential setting, you're talking about pairing two 15 amp circuits, you're still only going to get 15 amps at 240 volts

The low amperage leapt to mind as a reason to NOT pursue this. A better idea might be to identify the 220 service you already have but may not realize. Many home kitchens have 220v 50a service for the electric range, and many home laundries have 220v 30a service for the dryer. If you have one of those you might gin up an extension cord to bring power to your work space. Or move your welding space to a place near your kitchen / laundry.

And warn your spouse first!

I have a 30 amp 220 outlet at home. This idea is for those small outside jobs where 220 power is not available.

I have a dual voltage welder Everlast 160STH. I recently used it in the 110 volts mode feed by a long 100 ft 12/3 extension cord. Working with 3/16 plate with 3/32 6011, the machine made the welds ok but does not seem to have the same punch as when run on 220 at the same amperage. Starts were harder as was maintaining the arc. I know that my stick skills are rusty, but I had run some practice beads at home using the same on 220 and got better results.

so this rig would only be used to get 220 at 15 amps rather then run at 110 at 15 amps.

The concern of only one breaker tripping is a valid point. It would leave the machine with a 110 hot feed making what seems like a dead power supply really a hot 110 supply which could cause a danger. As for the welder I think that would not be harmed.

Mark

For a few houndred bucks you can make a 100ft extension cord for 220. For 600-800$ you can buy a gas generator big enough to run that machine anywhere you can move it.

If I was working at the same place all the time a 220 feed would be a good option, but I don't.

As for a generator, I have a 5kw with a 220 outlet but am hesitant to use that as a power supply since my welder is an inverter unit and have read they need a very clean power supply.

Have any of you used their inverter welder on a basic, non inverter generator?

Mark

I've done it when there was no other way to get through but I would not recommend it, I have no idea how it affects the breakers or if they would even trip so I don't use it regularly as I don't trust it.

Can you research the Total Harmonic Distortion for your generator? I've heard it's ok to run an inverter from a generator with less than 5% THD.

I've done something like that for a compressor till I got a proper breaker. I just used two adjacent breakers and put a cut off nail through the lever to trip them both although only one may blow it is much better to ger the proper one.

I have looked and its hard to find THD numbers even on new generators, Finding them for a 15 yr old machine would be next to impossible. That said I don't want to chase using that as a power supply

Mark

Mark, I can talk you through this, and how to do it (relatively) safely, if you want to go this route.

I hesitated at first, because you asked "if" it could be done, rather than how to do it, which suggested you have little experience with residential wiring. The benefit is, 220V at 15A has twice the power capacity in Watts. (Actually slightly more, because efficiency goes up.)

Steve S

mpete53 wrote:If I was working at the same place all the time a 220 feed would be a good option, but I don't.

As for a generator, I have a 5kw with a 220 outlet but am hesitant to use that as a power supply since my welder is an inverter unit and have read they need a very clean power supply.

Have any of you used their inverter welder on a basic, non inverter generator?

Mark

Both my inverter welders run on my Troy-Bilt 7 kW generator. It is not designated "clean power", but the specs I have sought out say it puts out less than 6% THD.

As for getting 240V from two 120V extension cords whose hot-wires come from different legs of 240V input service, yes it would work but it would have the downfall that was mentioned earlier: if there is a fault, there is no guarantee that both breakers will trip at the same time.

Oscar wrote:... if there is a fault, there is no guarantee that both breakers will trip at the same time.

There's two work-arounds for that, too. If your breaker switches are drilled, you can work from stacked breakers and use a small nail to link them (cut the nail so it doesn't interfere with the next breaker down). If they're not drilled, you can get linking clips to tie them together. Either way, one tripping will open the other.

I'm not recommending it, but it can be done.

Steve S

mpete53 wrote:If I was working at the same place all the time a 220 feed would be a good option, but I don't.

As for a generator, I have a 5kw with a 220 outlet but am hesitant to use that as a power supply since my welder is an inverter unit and have read they need a very clean power supply.

Have any of you used their inverter welder on a basic, non inverter generator?

Mark

I have numerous times. I made a pigtail connector from my welder to the Generator since my portable welder has a proprietary, hard wired plug on it. I've TIG welded with it, stick welded with it, and even done some aluminum MIG. Worked fine.

Running a 100' extension cord will reduce the available power along that cord.ertajnly upscale the gauge of the wire if you must run that far. I use a heavy 50 ex'tension cord and use 25' work cables. That gets me pretty far when I need to be flexible. I also installed an extra 220v outdoor plug on the house, conveniently directly below the main panel. This allows me to deal with work outside the shop with my extension cord and still get 220v. Total cost was about $80.

I have only ran a transformer machine on a genset but I have a friend who has 3 inverter machines that have been run off of coleman and coleman like generators for well over ten years almost daily and none of them have missed a beat so far.

the biggest problem he had was when he first started he had to up the size of the breaker on the generator because the 30 installed from the factory wouldn't carry it, he up sized it to 50 which sounds iffy but it solved the nuisance trip problem and he has yet to hurt a machine so my guess is that he had a weak breaker. I just questioned him about it a few months ago because I was considering a mobile set up and he told me he has had enough success with it that he just bought another machine and generator to add another rig to his fleet.

hope this helps.

creek