I have used my generator for a few years to supply power for some lights and to run my well pump during power outages. The last two times I have ran it (last few weeks), the pump will not run. My generator is a 5500 watt, my well pump is 1/2hp, 220v. I have turned off the large users in the house, refridgerators, freezer, tvs, and still the pump won't start. I can switch on/off a fridge at the breaker and hear the generator load up just slightly for a second, but doing the same with the well pump, there is no load noticed. Yet when the grid power comes back on, the pump is fine. The only thing I can think of is the pump is worn somehow causing a higher required starting load than I had before. Anyone else have any ideas, or how I might test for what the problem is? Thanks for any help.

 

There is no pump on a generator unless it has a fuel pump.
Checked the outlets for power with a volt ohm meter?
Make and model of the gen set might help trouble shoot it.

 

If the pump was somehow drawing a much higher load...the gennie would bog or trip a breaker. It sounds like the pump is not getting power at all when on the gennie.

How is it connected? Cords plugged in to the gennie or an inlet on the house with a transfer switch? Do you have a volt/multimeter that you can check the supply to the pump?

Since it's a 240V load that isn't working, but the 120V loads are..possibly one leg of your 240V output is the problem.

 

The generator is connected to the house feed through a manual transfer switch out near the meter. Yes, I have a multimeter - I can check voltage going to pump switch. Makes sense about bogging down the generator if trying to start at all. Thanks.