Three Phase Welders

[HandBuilt]

There is always a large assortment of old 3 phase stick welders around my place for super cheap. I have always wanted to pickup a really old DC welder for a power source for a lowbuck TIG setup, and I use a stick welder for a lot of stuff, including all my 4wd building work. I just have more skill with stick than a MIG.

Is there a way to use a 3 phase welder on 220V?

[xj4rocks]

you'd have to get a "??" (forget what they're called) to switch it back to single phase power. 220 is single phase. Those phase converters get $$$.

[HandBuilt]

Rotodyne (Rotadyne), yeah I know, thanks, but they are loud and annoying. I was wondering if I could use single phase through it as is. All it is is a coil, and three phase or single phase may affect the operation, but in DC mode I am trying to think about how it would affect anything. A welder is just a big transformer and if the three phase AC was hooked up like I think it is (not an electrician by any means) it should be the same hookup as a regular welder (2 power and ground). Of course any AC power out of the welder would be different, but I think that the damn thing might actually work on 3 phase in DC setting.

[fj40guy]

Typically no switch, especially on older machines (big heavy transformers).

Modern machines will convert the AC to DC then back to AC as needed. Lots of electronics, and "hook up to just about anything". aka Millers "auto-link".

Only way to running those OLD 3 phase TIG welders... buy a big old three phase generator set. :( The "phase convertors" that are used to START 3 phase milling machines, lathes, etc... just won't supply the power for the welders. They are only meant to get a 3 phase motor "up to speed" then switch out.

Around Military bases... you'll find "gen-sets". Spotted one that had a big ol single phase motor that powered up a three phase generator. Still cheaper, and easier, to find a suplus three phase generator.

Tom :usa:

[HandBuilt]

Typically no switch, especially on older machines (big heavy transformers).

Modern machines will convert the AC to DC then back to AC as needed. Lots of electronics, and "hook up to just about anything". aka Millers "auto-link".

Only way to running those OLD 3 phase TIG welders... buy a big old three phase generator set. :( The "phase convertors" that are used to START 3 phase milling machines, lathes, etc... just won't supply the power for the welders. They are only meant to get a 3 phase motor "up to speed" then switch out.

Around Military bases... you'll find "gen-sets". Spotted one that had a big ol single phase motor that powered up a three phase generator. Still cheaper, and easier, to find a suplus three phase generator.

Tom :usa:

Thanks, that's what I'm finding out about these things googling around.

Man, this section is awesome!

What about using two 220AC feeds, and then using a capacitor on the other feed? I've seen some old guys do this on lathes and other motors. Not sure if that works for a welder.

I would imagine that the AC waveform would be a little flaky, but does it really matter if you're sending it through a rectifier afterwards?

[fj40guy]

What about using two 220AC feeds, and then using a capacitor on the other feed? I've seen some old guys do this on lathes and other motors. Not sure if that works for a welder.

Oh no, I'm a "old guy". :p

That is how I power up my 3phase lathe and milling machine.

Can not do that for a welder. The welder takes too much current.

This is why you can find a good old three phase TIG for cheap... not much use, unless you happened upon a screaming deal on a 10KW (or larger) 3 phase generator.

Tom :usa:

[HaWiiLuVeR]

i have a 3 phase compressor that i would like to run because its huge. i might have some other equipment thats 3 phase also. just looked on ebay and found a phase converter they say is for 5hp motors. it says thats good for 20 amps. this same seller has converters going up to like 40hp. would something like this work for a welder or plasma?