Three Phase Power and Welding

[BrokenTrack]

I知 not certain

I am thinking about just buying a 3 phase generator as they are less costly to buy than single phase generators, then just split the power at a loadbox. The extra cost of the loadbox will mean the cost is ultimately the same for 3 phase as single phase, but enable me to have both at my house. That way I can buy welders/machine tools with 3 phase motors, but also have backup power for my house if I need it.

A 30 KW 3 phase generator is only $1800.

I was hoping the guy who has Everlast Welders would chime in, only because I like Inverter Pulse Welders and wondered since pulse has AC Secondary Voltage, if three phase power as background amperage would make a difference on weld quality in that application? I would think it would be a lot smoother, and maybe give you more pulses per second.

I was reading this week that some pulse welders are approaching 400,000 pulses per second now. I would think AC background amps would be the only way to get that???? Crazy for sure.

 

[Gary Fowler]

Anyone run a phase converter? I have some equipment that would have a lot more output on 3ph. Not sure if it's worth it.

I see a lot of welding equipment for cheap but all 3 phase. If a converter is $100 that would justify buying. I just saw 3 Miller machines with wire feeders and controllers for 500or 600 bucks on craigslist. But I have not idea how to hook up a phase converter nor where to buy one.

 

[Gary Fowler]

Anyone run a phase converter? I have some equipment that would have a lot more output on 3ph. Not sure if it's worth it.

I see a lot of welding equipment for cheap but all 3 phase. If a converter is $100 that would justify buying. I just saw 3 Miller machines with wire feeders and controllers for 1000 bucks on craigslist. But I have not idea how to hook up a phase converter nor where to buy one.
Miller Welders - tools - by owner - sale

 

[Gary Fowler]

Anyone run a phase converter? I have some equipment that would have a lot more output on 3ph. Not sure if it's worth it.

I see a lot of welding equipment for cheap but all 3 phase. If a converter is $100 that would justify buying. I just saw 3 Miller machines with wire feeders and controllers for 1000 bucks on craigslist. But I have not idea how to hook up a phase converter nor where to buy one.
Miller Welders - tools - by owner - sale

 

[BrokenTrack]

The only advantage there would be smoothness or what not. With 3 phase you are splitting up the power across multiple cables rather than just 1 (ignoring the neutral part of the equation). That means you can get more wattage across smaller cables, although you have more of them. It's easier & more efficient at higher wattage to run 3 phase with smaller wires. But converting from single to 3 phase means you'll need a beefier wiring & a phase converter. You won't gain any watts on the input side of the equation. The machine could handle more watts though.

I have always heard this, but I am trying to figure out why it would be that way.

It would like be drinking from (3) smaller straws, rather than one bigger copper pipe, but how would that be smoother? A person is still getting enough milk from the bowl. And so it would be with welding, a person is still getting enough electricity to maintain an arc, it is just coming from (3) wires instead of (1).

I could see if a person was welding with AC in the rare instances that is used, but we mostly use DC power, and so there is no frequency to contend with (unless using pulse welding). The only places I could see where it might be smoother is where AC is used...

AC Stick Welding
AC Aluminum Tig
AC Cast Iron
Pulse with AC Secondary Background

 

[the old grind]

I see a lot of welding equipment for cheap but all 3 phase. If a converter is $100 that would justify buying. I just saw 3 Miller machines with wire feeders and controllers for 500or 600 bucks on craigslist. But I have not idea how to hook up a phase converter nor where to buy one.

Some Millers can be converted from 3-ph to 1-ph using a model-specific Haas-Kamp conversion. This Spring we converted two CP200s and a CP300. The 200s required two caps ea, and the 300 needed four to go 'by the book'. (Each capacitor uses a bleeder resistor vs store a potentially dangerous charge when shut down.) <$50 to buy the bits for each, and Pat's employer was giving away old Millers.

If you get on the Haas-Kamp conversion sites and threads you should find the detailed instructions. Cheap as we are we're welding a lot here with 100% CO2 using beverage svc bottles and the thread adapters for such that come with some gas valves.

Rotocons need the legs balanced for load. Static converters are the pits w/o an idler motor added. Running extra motors/machines no-load can be a way to smooth out the phases. YMMV

Phase Perfect (TM) is best if pricey, costs way less than adding three phase service, and doesn't need tweaked for load like a RPC. Several $K to play.

Here's a video of a guy converting a CP200 pretty much the way we did our two side by side. YouTube

 

[BukitCase]

Here's a couple videos that should help explain 3 phase

YouTube

YouTube

One thing to remember - just because you add a diode in an AC circuit, this does NOT mean you will get DC that is a constant voltage (like a battery) - the vids sort of cover this. They're a bit "wordy" in spots, but if you watch BOTH all the way through, it should clarify some of the misconceptions I've seen on this thread. If I were to "improve" on them it'd take a LOT more time than I have at the moment; (Life is the crap that happens to ya while you're busy makin' plans ) ...Steve

 

[Industrial Toys]

I added these caps good for the 600 Volt line, to try and correct the manufactured phase that the Lincoln Computer did not like. It helped, but the Math changes when the load changes.



Having to start and stop a Rotocon, everytime you want to weld was a giant PITA! And my 10 HP unit drew something like 500 amps or more inrush current!