3 phase welder from Split Phase / Bi Phase supply 480v

[robertlaurenson]

Hello all, I have discussed my power install before as i am sure a lot of you will remember as it is quite different to a normal setup. I have a split phase / Bi Phase system, 2 phases coming into the workshop from a center tapped transformer. 240v phase to neutral and 480 phase to phase. I have been looking at machinery and have bought some of the equipment already which is running on VFD's so not an issue power wise.

I now need to get a large Mig welder to complete the set, most of them as soon as you go over 250A they have to be 3 phase.

My question is relating to the inverter type welders on the market, i am not sure if what i am going to ask is even remotely possible but with my minimal knowledge on these welders and what i can find on the internet it seems like it may be possible.

My question is as follows, can i take the 2 legs i have with 480v between them, say put them in L1 and L2 of the welder and then put a series of links in between L1, L2 and L3 to in effect make the machine think i am powering it from 3 phase. i.e it will see power across all phases. the only thing with this is the phases wouldn't be balanced 120 degrees apart but i am not sure the machine would be this "clever" and would more be looking for a voltage across each leg.

In my simple understanding of the way these inverters work they take in a "3 phase" supply and convert it to DC and output it through a second inverter in the machine. Any help on this would be greatly appreciated. It is a big outlay to buy a 3 phase welder of this size and not much point doing it if this wont work.

My other possible options are a Rotary converter, or a Drives Direct digital one.

Thanks in advance Robert
 

 

[Andy™]

doubt it. for a start youd probably fry the components. they will be designed for 400v, not 460v. they will also be expecting a voltage between each phase, not 2 of them to be the same phase

 

[robertlaurenson]

doubt it. for a start youd probably fry the components. they will be designed for 400v, not 460v. they will also be expecting a voltage between each phase, not 2 of them to be the same phase

The welders i have been looking at are rated 400 to 560v, possibly due to them being from USA. 

With that in mind do you think it would work? 

Thanks

 

[Andy™]

With that in mind do you think it would work?

same as before... probably not. why dont you ask the manufacturer, they should know

 

[kerching]

same as before... probably not. why dont you ask the manufacturer, they should know

^^^^^^^^^^^ this...otherwise you may well have a very expensive smoke scented paperweight

 

[robertlaurenson]

Would this work? certainly looks capable of taking the voltage but is asking for a 3 phase supply? just depends i guess if its looking for 3 voltages, or 3 balanced phases?

https://www.rapidwelding.com/dynamic/DisplayItem.aspx?c=029015507
 

 

[Sharpend]

https://www.rapidwelding.com/files/MillerXMS425MPAOperatorsManual.pdf

Look at page 35?

It will be looking for the three phases not voltages. You seem to be adamant to not adopt the advice you’ve been given by the members? Your desire to have said machine outweighs your desire to accept what your problem is? 
perhaps you would be better speaking to the manufacturer as they may have had this issue before and have a solution or alternative machine? 

 

[robertlaurenson]

https://www.rapidwelding.com/files/MillerXMS425MPAOperatorsManual.pdf

Look at page 35?

It will be looking for the three phases not voltages. You seem to be adamant to not adopt the advice you’ve been given by the members? Your desire to have said machine outweighs your desire to accept what your problem is? 
perhaps you would be better speaking to the manufacturer as they may have had this issue before and have a solution or alternative machine? 

Yes i understand it willl be looking for 3 phases, and saw page 35 before you pointed it out. 

What i would think is it will be looking for a power supply from each phase rather than being clever enough to be monitoring phase shift. 

Thats what i was getting at. 

 

[kerching]

 

but what do i know, see present wife for further details

 

[Sharpend]

Okay let’s simplify this, 

so a paddle steamer has a wheel with three paddles equally spaced 120°, the boat moves along happily. 
a second paddle steamer had a wheel with three paddles only one broke so got strapped the the second one, it still has three paddles but is the boat moving as well as boat one? 
 

NO, it is lumpy erratic and slow eventually the motor packed up! But that’s not right it had three paddles! Cried the captain, the engineer had to console the captain for his lack of technical understanding. 
 

Moral of the story, listen to the engineer as he knows what he speaks of. 

 

[Phoenix]

You've been given the only answer we can give "Ask the manufacturer". Its not out of the question for it to be able to work like this but its not a certainty either. Unless you have the welder and wouldn't be too worried if it went pop then I suggest you ask the manufacturer, no one here will be able to give you any more information than that

 

[Andy™]

Yes i understand it willl be looking for 3 phases, and saw page 35 before you pointed it out.

What i would think is it will be looking for a power supply from each phase rather than being clever enough to be monitoring phase shift.

Thats what i was getting at.

it will be expecting voltage between them and therefore able to get power from it. since you cant get power from line to the same line, it wont work well, if it all

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