Another breaker tripping problem

[Miller Kevin]

Most likely and you would typically see visible signs of failure as well.

[Crazyman]

Thanks Kevin. If the transformer has a short wouldn't it do it on 460?

[Miller Kevin]

Crazyman,

I have attached the linking diagram for your unit, please double check the correct linking for 230. If the linking is correct then someone has either moved some wires around on the back of the primary board or the transformer has an internal short.

[Crazyman]

Serial # kk025163
stock# 903604

[Miller Kevin]

Crazyman,

Do you have the stock number or the serial number off it?

[Crazyman]

I have also checked the plug from the welder when it's switched to 230v and it reads fine. Nothing going to ground or shorting out like it seems.

[Crazyman]

I've checked the plug from panel. I switched it back over to 480v turned it on and it doesn't trip the breaker. Could the diagriam that shows how to change it over be wrong?

[Cgotto6]

Possibly wires shorting between the panel and outlet or inside the outlet box. With the circuit off, check for continuity between hots and ground/neutral.

[Sberry]

Re read and check, usually an instant trip means its wired wrong.

[Crazyman]

I have a Millermatic 250 that I got from work. It worked fine at work with 460v. I switched it over to 230v and it trips the breaker (50amp) as soon as I turn it on. I can change it back to 460 and it don't trip the breaker. (But of corse on 460v it doesn't work right)