Turning an AC stick welder into DC

[Brad_Blazer]

"The main reason why I'm looking into it is the reduced current requirement when welding with DC will allow me to use slightly bigger rods than I can at the moment."

That will not happen. AC-DC machines typically put out enough fewer amps in the DC mode to more than negate the reduced amps required for a given rod using DC.
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Those WeldSmart inverters sold over there seem reasonable. My buddy bought a similar 200amp inverter welder off ebay and I have it in my shop right now trying it out for him. It's an impressive little welder.

 

[rhamer]

Rhamer,

For the US and here in Canada we run 110 V, 100 amp service. Some new housing is being pushed up to 200 amp service because of the rise of electrical stuff like computers. This is all 60Hz cycle AC current.

Ovens, Hot Water tanks (electrical), Furnaces (electrical), Welders run on 240V 30 - 50 amp breaker. Pretty much anything else runs on 110V max at 15amp.

There is no 3 phase circuitry in a home. To bring that kind of power into a house would require a high cost for installation.

I have a welder that will produce 300 amps on a 240 volt single phase 45 amp draw. The highest output by a single phase machine at least far as I know.

I hope that has answered your questions if anyone else can add to this go ahead.

Thekid,

Thank you for the diagrams.

See that's the problem. You have a dedicated 45 or 50A circuit just for your welder. I only have 80A@240V for my whole property.

Is it normal for you guys to have such large supply currents available in a domestic house?

If you went to your local megalomart or whatever and bought a stick welder off the shelf, are they the 50A supply types?

Cheers

Rohan

 

[denmansoft]

Yes thats what we buy off the shelf 220V 50A. welder. Smaller 110V ones are available but running on a 15A circuit you don't get much for welding tractor type stuff.

Alltoys said the norm is 110V 100A for a house.
Actually it is 220V 100A and up. In our area a lot of homes are heated with electric baseboard heaters. these houses typically have a 220V 200A service.

A few years ago I got 200A service put in for my 5th wheel. It will shortly be servicing my garage and next year the new house.

 

[bobodu]

Never done any wiring outside of the US.but I wonder if your power is there and all you need do is upgrade your service panel.

 

[alltoys]

Alltoys said the norm is 110V 100A for a house.
Actually it is 220V 100A and up. In our area a lot of homes are heated with electric baseboard heaters. these houses typically have a 220V 200A service.

Thanks for showing that, the service is 220V 100A service not 110V my mistake.

I do know if I run my welder at full current while air arcing and wifey turns the oven on the breaker may pop. It has happened once to me. Since then I had the power company install a larger main buss fuse in the Meter Box before my fuse panel. Since then no more fuse pops.

Here is something else that puzzles me. The power lineman that installed the main fuse told me there are 3 sizes of main fuses before they can up the voltage to the house. Weird part is the main fuse in the Meter box was 40 Amp and he installed a 60 Amp. Since then I have had no problems.

Lineman told me that the fuses at the house or shop will pop before the main buss fuse would even at a 100 Amp draw at the house. Why I am not sure.

The higher main fuses were a slight increase in moneys per month but at least I can run my machine while wifey is cooking.

Farmers will run with anything from 200 to 400 Amp single phase service.

 

[denmansoft]

The line fuses are real slow blow type of fuses. They are there to protect your neighbour hoods power in case of a catastrophic short in your house ie a fire...
Any overload you put on will pop a fast blow breaker long before the line fuse starts to warm up.
I am sure if you put your max panel load (100A) on solid for 10-15 minutes it would blow that line fuse. keep in mind that most welders(the people) don't hold a continuous arc so your average is probably 20A when welding. Kitchen stoves also have thermostats and on some some interlocks such that they will rarely draw anywhere close to the 40A max for any amount of time.

 

[PILOON]

OK guys, I went and ordered 4 diodes yesterday as I have always wanted to try DC welding!
Darn, this site keeps costing me $$ as I am a die-hard DIY guy that like to try out ideas.
(Gotta build a new shop as I am running out of space, = another project!)

When we got married, I bought a table saw for me and a sewing machine for the wife.

I now have arc and gas welding, wood and metal lathes, various saws and just about every powered hand tool (and many duplicates) as well as large range of pneumatic tools.
My wife has been in and out of most crafting techniques from stain glass to complete upholstering projects.

Now that we are retired I may have to create his and her workshops LOL !

But then we are retired in a house that we built from scratch on a lakeshore with $0.00 morgage + a couple of revenue properties. (fanny may go s---w yourself!)

LOve this site!

 

[rhamer]

Never done any wiring outside of the US.but I wonder if your power is there and all you need do is upgrade your service panel.

I could get more power to my shed from my existing panel if I really wanted to, but the problem is you cant buy single phase welders that draw more than 15A @ 240V.

In order to go bigger, I need to go 3 phase, if for no other reason than, I can't get the equipment.

Although, I have heard stories about running 3 phase welders on a single phase, because in reality they are actually a single phase unit, but are wired to a 3 phase plug because they need the current supply available from a 3 phase outlet.

Cheers

Rohan

 

[Bill_C]

I could get more power to my shed from my existing panel if I really wanted to, but the problem is you cant buy single phase welders that draw more than 15A @ 240V.

In order to go bigger, I need to go 3 phase, if for no other reason than, I can't get the equipment.

Although, I have heard stories about running 3 phase welders on a single phase, because in reality they are actually a single phase unit, but are wired to a 3 phase plug because they need the current supply available from a 3 phase outlet.

Cheers

Rohan

Huh? Maybe I'm losing something here... The Lincoln "Tombstone" and similar Hobart/Miller welders are 220V, "single phase" welders, needing 50 amp (or thereabouts) supply (although many people have said they have successfully used a 30 amp clothes drier circuit).

Welders that are rated 3 phase are not merely a single phase unit hooked up to two legs of a 3 phase circuit (well, maybe there are some welders of dubious origin that might be made that way). They use all 3 phases, with a transformer made specifically for that, resulting in decreased power usage and longer duty cycles.

There may be some confusion here because a 220 volt circuit, though often called single phase, is really a 2-phase circuit. Each phase is 180 degrees out from the other. There's an intermediate neutral; taking either leg with respect to neutral yields 110 volts. So there's 3 wires--one hot leg, the other hot leg which is 180 degrees out of phase with the first, and the neutral. There may also be a ground wire but it's not needed for actual operation of the machine.

3 phase power has 3 wires, but they are all hot, and each leg is 120 degrees out of phase with the others. There may of course also be a 4th ground but again that isn't needed for the operation of the machine. Pulling significant loads from just two wires (of a 3 phase supply) creates an imbalance which can harm the supply transformer.

Oh, here in the US at least, it's not easy for residential customers to get 3 phase power from the power company (too much hassle for the power company to set it up for the low demands of a typical homeowner). Most folks that want 3 phase run a converter to generate the 3 phase themselves.

 

[RWolf]

I believe I understand what rhamer means about a single phase welder wired to a 3ph circuit. During my time in the Army I worked on equipment that needed 3 phase power and at times had to wire in some 110 and 220 volt equipment. First a little primer. Single phase i.e. would be 1 hot and 1 neutral. This could be 110 or 220. 3 phase consists of 4 wires, 3 hot and 1 neutral. Now you might say wait a minute my 220 has 2 hot wires and a neutral. Sort of. If you look at your main panel you see that the neutral "and" the ground are one and the same. It's still considered single phase. Here's where the fun begins as you "can" get just about any voltage from a 3 phase line. Here's how. If you take "any" hot line to neutral you get "approximately" 110 volts. If you take any 2 hot wires on a 3 phase circuit you will get "approximately" 208 volts which is within most specs. for a 220 volt appliance. And of course your 3 phase 240 curcuit. What I believe rhamer is saying is that their standard is to run a 3 phase line into a building and just use 2 phases (208) for the welder etc. Yes they are 120 degrees out of phase and that's why you will only see 208 rms volts. It does work but "can" cause problems with certain types of equipment. In the US if you need three phase power I believe they use a special type of transformer with a special type of capacitor to create 3 phases of power but I'm not sure.