PTO Generator

[amgen]

gear or belt driven ? the gens have to be locked together at same phase angle or you can't join the legs that way. if gear then you can shift teeth position until the 240 is actually the addition of the 2 120's. if belt driven, you can never guarantee same phase angle so you may have to do something else with output loads.

don's 2-cents

[b1arrk5]

A little slow on the comback here, I'm sorry amgen, I didn't get your question until today. Each generator is 115 vac @7500 watts. They are gear driven to provide the correct phasing. My guess is that one set is working and backfeeding 115 to the second. I can get 115vac out both gensets, but only 115 7500 watts. I'm going to set it up and disconnect the transformer and verify the both units are putting out. Then I'll get it working. I have other gensets, but this will be my largest, aNd most usefull. I want to then monitor output and automate the tractor regulation setup.
Jerry

[AvionicsMaster1]

Niagara Generator has a home page and appears to have a customer service number. Sears looks like it sells parts for some Niagara/Generac generators. Contacting either may yield a manual or operating instructions. That might get you rotational position without having to measure phases. I'd bet there are some markings on the shaft/housing to ensure correct phasing. I also wonder if the xformers tie may be corroded. That would be easy to check by measuring resistance between neutrals.

If you go the transformer route to compare phases I'd caution you to be very careful. I don't think there will be a GFI and if so it won't quit until those 60 amp breakers trip. It could tingle a bit. I don't see any way to do it differently though if there are no markings to ensure correct phasing.

[amgen]

so, if there are 2 independent windings which can be hooked series or parallel, test phasing as follows,
if you are sure there are no other connections on output legs, you can join 1 connection and meter the legs to determine the phasing and output voltages for different hookups. careful