Community Forums

RVH.O.G. · 06-17-2018, 01:12 PM

I am wanting to use my Onan 8000 to power my Millermatic Mig Welder. It is powered with 30 amp 240 volts. Now I'm talking about 50 amp shore power cord unplugged, and using generator power. Using a multi-meter, black lead on the white neutral leg / red lead on the black or #1 leg =120 volts. Same with the red or #2 leg. But when I test between the #1 leg and #2 leg = 0 volts. When I test between the 2 hot legs at the house = 240 volts. Why isn't the generator producing 240 volts.

Mr_D · 06-17-2018, 01:14 PM

Won't work with that gen set. Only the 10 and 12.5 KW Onan units put out true 240 volts.

Isaac-1 · 06-17-2018, 08:16 PM

Because most RV generators are wired to output 120VAC only, there are technical reasons for this having to do with load balancing, and higher chance of burning out a 120/240V generator of the same total watts of output if the load is not balanced equally between the two hot lines. So since most RV's contain no 240V loads, RV generators tend to be built to only provide 120VAC.

Mr_D · 06-17-2018, 08:25 PM

Onan does produce some commercial units that output 240.
My rig is one of the relatively few that does use 240 for the dryer.

twinboat · 06-17-2018, 09:16 PM

You should be able to rewire it to 240 volts. As it sits, the windings are in parallel but can be rewired to series.
Find the instulation guide. That will show what changes need to be made.

RVH.O.G. · 06-18-2018, 07:04 AM

Hey everyone thanks for the information. I will look at the installation manual I have that came with the unit. I will also contact Onan if I can to get their input, to see what all is involved. And (IF) I chose to make the change I will have the supervision of an Electrician.

Mr_D · 06-18-2018, 07:16 AM

I don't think it can be done easily and probably not worth the effort. Plus, once done you still have the problem of switching back so it'll run the gen.
But, let us know if it can be done and how it works out for you.

RVH.O.G. · 06-19-2018, 05:44 AM

You are correct it will not be easy. I contacted my Cummins Dealer in Harrisburg PA. This is the shop that service my 2005 Monaco Diplomat 38 PDQ 8.9L ISL every spring. They are also an authorized Onan Service Center. After talking to Larry, the service manager, he confirmed that it is wired parallel. He also informed me with the model I have the Stator would have to be replaced with a Stator that is wired Series in order for it to produce 240 volts. This is WAY more then I want to do. So I guess I'm in the market for a used portable generator.