MIG welders.

[Monkeyblaine]

Has anyone got any experience with MIG welders. I have been asked to install 3x 32a sockets as to supply the welders. My question is what CB's should you use. I would imagine a C type or D type?

 

[Marvo]

Unless they're really old and have a kilowatt rating that will mean they draw close to the 32 Amps then a C curve should be fine. Most welders built in the last few decades have some kind of inrush current limiters built in.

 

[Monkeyblaine]

Thank you Marvo

 

[Robotstar5]

I installed quite a few in my last job, usually put C curve mcbs in, did use a couple of B curve without any problems, but most of the welders only ran at about 30-40% capacity due to the material being welded.

 

[somersetsparks]

I have always used C, even the biggest oldest oil cooled welder I have seen was ok on a C16 Double pole (split phase).

 

[Marvo]

I'm not sure about split phase (180degree) supply, the higher phase to phase voltage would certainly need to be accommodated when specifying OCPD's.

 

[somersetsparks]

I'm not sure about split phase (180degree) supply, the higher phase to phase voltage would certainly need to be accommodated when specifying OCPD's.

Can easily be 500v on split phase, as its most commonly found on farms that tend to have a poletop transformer outside, Difficult though as most standard mcb's are only rated at 415v, however phase to neutral is only 240v so probably not a problem!

 

[Marvo]

It used to be used in our area many yearsago but they've phased it out (no pun intended). I've only come across two installations in remote areas in the last 20 years so it's not very common. Like you say if it's single phase and neutral then it's not an issue but if there's two phases in the same DB it becomes a headache.

 

[somersetsparks]

It used to be used in our area many yearsago but they've phased it out (no pun intended). I've only come across two installations in remote areas in the last 20 years so it's not very common. Like you say if it's single phase and neutral then it's not an issue but if there's two phases in the same DB it becomes a headache.

Still common on farms around here marvo, it lends itself quite well to the setup I suppose, generally they give a single phase to the farmhouse, a single phase to the farmworkers cottage and the split phase to the farm for the dairy, I suppose it depends on what DNO area you are in.
Quite often I find the farms will have a couple of single phase boards for general power and just a couple of switchfuses for the split phase loads i.e. vac pumps etc.
However with the cost of split phase motors now, I'm not sure how long it will remain useful (other then just as a means of providing 2 100A supplies) in fact if they fail most split phase end up getting re-wound as its cheaper then getting a new unit. I would very much doubt they would provide new split phase supplies now!