Miller/ Bobcat 225G

[HelgothJ]

So today at work I was assisting a welder with welding track onto a trailer for a small childrens roller coaster we were re-furbishing, at our disposal was a Miller/Bobcat 225G 8 KW welder/generator used for welding (arc) the track to the trailer bed, and using one of the 120 outlets to power a grinder that I was using. The 120/240 plug is a 40 amp one, and when the load got to heavy on the plug that I was using (20 amp), it would trip one of the 40 amp breakers instead of the 20 for the outlet I was on. what im wondering is that is the two 20 amp breakers for the 120 volt outlets fed off of the two 40 amp breakers to the 120/240 plug. The engine was running at fast speed under practically full load (arc welder running) while grinding, could the welder load contribute to this?

[Millerman]

Yes, the 240v breaker feeds the 20a breakers for the 120v. Where was the rheostat (fine adjustment) set while you were doing this? It probably should not matter as far as blowing a breaker but you want it from 7 to 10 if you are welding and using aux power at the same time. Could be a weak breaker.

[HelgothJ]

Icant exactly remember the settings, but I think the amp deal was set at 85-225 ( I think thats the one it is) the one thats before the last setting, and I think it might have been on 5 or 6. breaker popped before earlier because we had a **** of a load coming out on one of the 120 outlets, since the right plug didnt work, the left one was running one line to a grinder, and another to some lights on a starship ride the company electricians were testing. So it popped that, we reset the breaker, pulled out the plug and yelled at the electricians, and pointed out that a caterpillar 500 KW generator that cranks out the high amp 3 phase for testing out the rides had 120 outputs on one of the distribution posts. But I think when it tripped the second time, my grinder got bogged down a little and probally pulled too many amps and the welder was goin strong layin down a long bead for the section of track that we were putting into place.

The bobcat sits on the bed of a boom truck and is pretty much outside 24/7 and merino (where the shop I work at) gets a good bit of rain now and then. So there is no cover on it and is exposed to the elements, though really the only protection to it is a shop fabricated metal cover that goes over the engine. but besides the fact its outside 24/7 its one helluva machine and no matter what gets the job done. Thats the power of blue at work