ECN Forum Forums General Topics of the Trade General Discussion Area How to get this to work?

Bjarney,
I was just thinking the same thing.

For temp power, 277 to ground.

I looked into the welder, it uses a transformer and a reactor? I'm going to assume that the transformer cannot be rewired to higher voltage due to its a cheap welder. I'm getting the welder for real cheap so thats why I'm trying to make it work and I know I've got some jobs that I'll need it.

What about useing a heating element in series with the welder? Like a fin type element compact enough to make it worth the effort?

A resistive ballast MIGHT work if the current draw was constant, but a welder is definitely NOT a constant current load.

Transformer or genset look like the way to go here.

Have you tried this welder plugged into a normal 20A 120V circuit?
As Trainwire mentioned, the unit won't draw the maximum current unless the welding current is turned all the way up.
I used a Lincoln 225 "buzz box" for corral fence repairs for years. It was powered by only a 20A 240V circuit, sometimes with 300'+ of #10 and #12 extension cords. Although the welder had an input rating of 50A, I never had a bit of trouble.
I don't think the 277 to ground connection is a safe idea under any circumstances...S

I have used it in my garage and it blows the 15amp if I exceed the duty cycle. That’s easy since it’s only got a 20% so that’s 20% of 10 minute interval. If their is sufficient voltage drop the duty cycle gets shorter.

What are the potential hazards of the 277 to ground? The chassis and conduit could carry current. The ground could be wet and a shock hazard could exist. I think most likely the clamp will loose its connection and I will lose my full 277 and smoke my welder.

JohnnyB, you said in an earlier post that you 'assumed' you didn't have a higher voltage tap in your welder. If it is 'cheap', it may be designed for all countries and therefore have the taps you are looking for.
The 'resistance in series' may work, but you have to choose it for your optimum amperage.

It's a Sears mig welder, 70-80 amp. I think they are made by lincoln. I looked in the parts break down and it didnt show any extra taps. I thought the difference between us and everyone else was just 60HZ to 50HZ.

Hey Pinemarten, I too like to read about astrophisics. I just re-read "A brief history of time". Have you read "The elegant universe" or are you familiar with Brian Green at all?

The easiest way to check the taps is to take it apart. It may have an auto-transformer with no labels or labels that don't make sense.
Went you wire it to 120V you should be able to meter the voltage on the other taps. If another tap meters 208, 240, 277, or 480 etc then that is where you tie in to that voltage.
If you have a motor winding shop in your area they can take a quick metering of it and make sure you:
DON'T TAP INTO THE SECONDARY!
That would be a noisy, smelly, painful, and generally bad thing.

I don't read many books on astrophysics but I studied it in highschool. My best updates come from badastronomy.com

I really feel the safest and only code / listing compliant way to use this welder on the roof is to find a source of 120 volt power that can handle this welder (20 amp 120 volt circuit) and run a cord from there.

The cost of a cord of large enough to deal with voltage drop may cost more then renting a gas powered generator.

A 5000 watt portable generator should easily power this welder.