Home 220 gen hookup issue

[Oldchevy4x4]

I managed to recently acquire a generator (used) and straight away me and my father started getting it hooked up to the house. We have it set up so it feeds into my main box and powers the whole home (winch intention to just limit power usage). It feeds through a 30a breaker with a 25’ 10ga cord so the gen can sit under my car port. The generator is a 7000w (10500w surge) Troy built. We went to test it and that’s when we got some weird things that are the source of my question. I shut off the thermostat and breakers to the hvac and the well pump and then we transferred over from grid to generator. Everything worked as it should, lights are on, all is well. We have 220 pole to pole, 110 poles to neutral. 60hz from poles to neutral. So I turned the breaker for the well pump back on and ran water so the pump would kick on. When it did the lights in the house flicker the whole time it runs. When it runs the voltage never dropped below 218. We did some more testing and noticed from pole to pole we get 200-300hz.

Any thoughts on the flickering and why we were getting 2-300hz across the poles?

 

[Lucien Nunes]

That won't be the real frequency, it will be close to 60Hz as it is inherently locked to the speed of the engine (except on high-tech inverter generators). The well pump motor is probably distorting the voltage waveform and/or upsetting the generator's voltage regulator, resulting in both the light flicker and the incorrect frequency reading on your multimeter (or whatever you were reading the frequency with).

Running larger single-phase motors on a generator can sometimes show up incompatibilities, so it is often recommended to use a generator much larger than the largest motor. It is hard to know what to suggest, as there might not be an actual fault here. Out of interest, what power rating is the well pump motor? Does the flicker still occur if you run 1-2kW of 120V heating or other resistance loads at the same time (which tends to help the voltage regulation) from one or both hots?

 

[Oldchevy4x4]

I have a 1hp submersible well pump. I had looked it up more and had manufacturers rating but I’ll have to find it again. I’m using a multimeter so far but I just got a small meter for the generator that has coil so I can watch frequency, current, and voltage all at the same time. I was wondering if it was just feedback of some kind. Now that I have the new meter I want to run a few more tests and I’ll definitely try running a heater. Should be striving for a 220 heater? Right now I have a couple space heaters I could run on opposite 110 circuits.