Subject: generator windings in parallel
I read the post and still confused. You rewire the head or the receptacles on a generator.
My wiring is just like the Coleman schematic. Why can’t I rewire the head to go from series to parallel before the breakers?
YOU CAN…… BUT should you ?
We don’t want to exceed the current rating of the ‘winding’. We protect that..
Consider a possible fault: a stator power winding goes open when the generator stator windings are wired in parallel. now we have one winding doing all the work, where is your breaker, and is it still adequate to protect the winding?
In the case of a common plug in, many if not most today are rated at 15amps. Exceed that by too much, and you can damage the connections in the plug itself.
The potential problem can come from that higher rated plug, and sometimes we see 30 Amp 120VAC plugs in use on the generator or attached to it. If we have such a thing as part of our generator, AND it’s protected with a 30 Amps fuse (an example), then we are set up to fry our winding via overload.
I talk in general terms, as there’s no way to keep up with the changes in generators, and exactly what you have. But I’ll attempt to share a potential difference in generator performance.
If you have a simple kiss generator head with a loose connection right where the two stator windings were tied together, and only one coil was providing power, (current) you’d see the voltage ‘droop’ far lower than expected as compared with two coils WHEN you increased the load. If we have no AVR at all, the operator of the generator might give pause, and wonder why?
With an AVR in use, might it see the voltage too low and attempt to boost field current, and if poorly designed, could it cause you even more grief? I think so fuse it or breaker it best.
If we open our household breaker boxes and see how they ‘breaker’…. it makes no difference how an American standard 120VAC supply is used. The breaker is at the head of it all, and if it’s used to help supply a 240vac supply, it returns to another breaker in the box, and makes use of another 120VAC supply that comes from that commercial transformer on the street, and this secondary is very much like our two stator windings, they rightfully choose to protect each of the 120VAC supplies, and should we emulate what they do?
This transformer we see on the pole, it’s designed similar to generator stators with the assumption that you will not need more current in any single 120VAC circuit than what one side of the center tapped secondary can deliver.
So… if you place that breaker and size it for the individual stator winding, you can save yourself a lot of trouble if things happen just wrong.
As a side note: There are some folks that are in areas unique, or they have been exposed to three phase, and they think those two hots delivered to your house are no more than two phases of the three. This is not the case, and we need keep it straight. Your house is normally supplied by a single phase, and that transformer secondary winding and the center tap confuse people.
As for the Professionals: They don’t always get power right. I remember one Telecom office that had a number of air handlers that were effectively used to keep the building at a slightly higher air pressure than outside. About 5 years after install, Switching Tech Jim Swanson, noticed that one air handler was running backwards! He didn’t know why. But he did know that the HVAC guy had changed the filters and checked on things a number of times. Fact is, it was more than one guy that had done the maintenance and found it AOK. I never ever noticed, Jim did! He didn’t know why, I did having a 3 phase AC back ground. I wrote a memo and sent it off to the power engineer to have two of the three leads swapped, it wasn’t our world, as most of what we did was -48 DC.
Swanson noticed a lot of things not done quite right, the type of man every crew needs, and always worth his weight in hard currency. And that reminds me.. Minimum wage was $1.25 cents when we were kids. That’d be $26.50 in silver melt value today..