Trips breaker as soon as plugged in

It sounds like the output rectifier is bad. Try contacting the manufacturer. Good luck.

The tip of the welder may need cleaned out, your feed speed might need slowed down, check the polarity is it straight or reverse?

If the welder is single phase 110v use a dedicated 20A standard household circuit. If 220v single phase use a 50A RV or weld receptacle connected to a 50A dual breaker with common trip. Make sure the breaker is the same brand as your panel. If the welder is 3-phase connect the wires B-O-Y (Brown Orange Yellow) at the breaker (3 phase 50A) and see if a color code match can be applied at the welder, although the only issue is whether the wire feed will run forward or reversed. If the wire feed is reversed then move any two wires of the B-O-Y set to change the rotation.

Would you write back and clarify what steps you have taken to narrow down your search? I'd like to know if the breaker is weak and needs to be replaced. Have you plugged your welder into another receptacle to see if it trips that breaker? I don't think the trigger has to do with this problem. The symptom is that as soon as you turn the welder on, it then trips the breaker. So this tells me that the electrical cord is not shorted. When the breaker trips, is there any delay or is it instant? If there is a delay, does it sound like it does while you are welding? Do you hear that "Transformer, buzzing noise"? The trigger activates the feed motor, that alone isn't enough to trip this breaker. Which make and size welder do you have? I really am dependent on detailed information, you are my eyes and ears. Please write back with any questions or new details and I'll do my best to help, good luck.

Hi:
Just make sure that if you are using an extension cable between your machine and the power outlet, this cable is at least a 12 gauge size, if you are using a 14 or 16 it's too small to handle the amps.
Other point is to check that your breaker is 20 or 30 Amp capacity.
Hope this help.

I am having the same exact problem on an old Hobart Beta Mig 200
sometimes i can weld for 5 minutes and other times as soon as I hit the trigger it trips the 50amp breaker. Any help?

Please don't give me a bad rating for this. Its just a little extra info. you didn't mention that may help you find the problem. Depending on your specific model, there should be 1 or 2 breakers on the unit it self. If there is only 1, it will shut down the entire machine when tripped. If there are 2, the top one is for the whole unit and the lower one is for the wire feeder motor only. There is also a thermal overload that will shut down everything except the cooling fan. Secure the trigger closed and let the fan run for a while to see if it re-starts when cooled. If the depth of the weld was stable before the problem occurred, I would suspect a short in the motor and not the rectifier. That is not a sure bet though. If the transformer does not start when it cools, UNPLUG the welder and short the transformer to ground to be sure the capacitor is discharged. Then isolate the feed motor and transformer and use an OHM meter to test them individually to ground for a short. With a little luck, it will be the feed motor. Please let me know if this helped at all. I am new and still learning how to explain what I am thinking. Thanks for writing us.
Roger

Have you tried it on another outlet, say at a friends' house, etc?
Reset button on the welder tripped? Double check the breakers and all connections. If it was working before, it should work now. Try some different breakers to check for good juice. Good luck!

Try replacing the circuit breaker. They can/do get weak and tend to trip before they actually reach the rated limit.

Get a volt meter, go to ohms setting , check transformer to ground for low to zero ohms reading. also look closely at transformer windings for foreign objects in between them, never know what you my find. If transformer is shorted to ground probably time to say some nice words over it before burial. Also just for kicks try a new gun on it, (there is a reason i'm asking you to do(this) see if you can find someone that has spare. A good honest repair shop would probably be reasonable if all else fails. to a least let you know if the transformers a problem. good luck

Signed
Former Miller Certified Tech.