Millermatic 200 blowing circuit breaker

[jes]

I have a Millermatic 200 that turns on OK and sounds good. However, after about 15-20 seconds of welding it will blow the circuit breaker. It's on a 60 amp breaker and the problem just started.
Any help on troubleshooting this would be greatly appreciated.
Thanks, Jim

[neophyte]

Jim,
How long have you been using this welder in this configuration trouble free? What size wire do you have going to the outlet and how far is it from your outlet to the breaker? How old is the breaker? Have you made any changes to the outlet recently? (removed it from the box and reinstalled it)
Neo