Tonyrico, if you are going to be running off of that generator I would recommend the smaller units over the 212.

Yup, the MM210/212 is rated at 27.1 Amps/5.45Kw.. the HH210 is rated at 24 Amps/5.33Kw. Those would be pushing a 5.5Kw generator pretty hard at it's top end. Also, unlike the HH210 and smaller units, the MM210/212 is not really meant to be a 'portable' machine. I have a Coleman Powermate 5000 which I occasionally run my HH187 on, and it seems to run just fine.. although I've never needed to crank it up to it's max while running on the generator, so I can't comment on it's full range capabilities in that configuration.

After what Roger said about the 155, I looked up the specs on it, the SP-175 and the MM180. The Miller/Hobart/Lincolns in that class all specify a draw of around 20 amps give or take. Lincoln doesn't report Kw, but the HH187 is rated at 3.88Kw, and the MM180 is rated at 4.1Kw, so it seems that they should, in theory, work with a 5.5Kw generator. What is strange is that while the Hobart/Miller specs call for a 25 Amp (Minimum) circuit breaker, the Lincolns calls for a 40 Amp one?!?