[B]Model #: (0057440) [/B][B]Serial #: ( 5644346)[/B]
[B]Natural Gas:[/B]
[B]Length of gas pipe feeding the generator: approximately 10’[/B]
[B]Size of gas pipe feeding the generator: not sure[/B]
[B]How long since the last full maintenance:[/B] not sure
[B]How long have you experienced this problem: noting[/B]

Purchased a Harvey flooded home back in May. It came with a 20kw generac with an auto switching panel. The PO said the battery charger had been broke and he used an after market trickle charger on it. I saw it run; bought the house as is. The generator got water in it, how much I am not certain. It could have been a little or submerged.

I had had a local generator company come out a few days ago for a basic service call, I wanted to know if it worked and was safe. First issue the battery was dead and the charger disconnected (suspect because it wasn’t working). Put a battery in and started it. Voltage at the generator varied between about 247 and 252. Same at the switching panel. I was trying to watch the best I could. The motor seemed to run at a fairly consistent speed, a little fluctuation could be heard but not much. Anyways, the techs said the voltage variation and the fact that it peaked at 252 was not correct and acted like if we used it to run the house things would get damaged. They were very hesitant to check the switching panel to have the generator power the house and asked my permission; at this point i was nervous and said don’t worry about it. Not knowing how much water got in they said replace it with a new 22kw.

So, that evening I started pricing them. And then I did a search for high voltage and voltage variations to see if I could throw some parts at. Stumbled on a thread on here and one of the replies said the generator should put out around 250 volts and variations are normal. so I began to doubt the techs that came, and I am posting here. I should have known voltage would vary, rpm varies slightly; makes sense. If the engine was under water there’d likely be water in the crank case or piston; rods would have bent or bearing rusted; neither occurred.

Is there somewhere I can go for basic troubleshooting? I bought a fluke meter, understand basic AC and DC electrical work, engine repair, soldering and circuit boards, etc.
Volts varying between 247-252 is within the acceptable range for these generators WHEN they are under NO LOAD. It's likely you would see the volts drop closer to 240 when a moderate load was applied to the generator. Before I tried loading it up I would confirm that the frequency (Hz) is 59 to 61, and if it is I would try to load the generator up by using all 4 kitchen stove eyes boiling 4 pots of water. If the generator does have a hidden fault , you aren't likely to damage a stove (during the test you would first turn OFF all other circuit breakers before allowing the generator to transfer the load).
I would run it unloaded a couple of hours to try and force moisture out of the windings. If you have any chance of saving it the last thing you want to do is put a load on it with damp alternator windings. I would like to see something below 250 volts no load before I transfer to the house.
Thanks for the help will try to run it for a few hours and monitor. I have a gas stove, any other suggestions to load it up?
pretty much any resistive type appliance would be a good test or central air if not a inverter setup,lights,fans etc....determine how far water got up to.
any water from harvey is evaporated by now but the crud and salt would still be there.i would check the rotor slip rings and brushes and run it for a while whilst checking volts and hertz.
once satisfactory repeat test under load.
if submerged,any of the sealed bearings will have a short life.
I would find another dealer. The slip rings and rear bearing should have been checked. The windings should have been megger tested. The oil and all filters should have been changed before starting. After all the checks were made, the gen should be tested using a load bank, not the house load. The transfer switch can then be tested as a stand alone unit.