I have a customer that had installed a 12KW standby 6 yrs ago. However the contractor never completed the job. All I had to do was connect to the outside connection box. The unit started on power loss simulation but will not generate power. I am only getting 18 VAC L-L, and 9 VAC L-N.

Has anyone ever encountered this situation? I am leaning towards 1) brushes stuck - due to 6 yrs of no use
or 2) voltage regulator.

Thanks for any input.

Google "flashing generator". You need some residual magnetism to get the generation started. Sounds like the field has lost that magnetism. It's simple proccess. There are several ways to do it.

I had a broken field connection on a 900 KW Marathon/Cat Genset cause that problem.
Joe

Thank you, Gentlemen. I was not aware of the flashing situation. This sounds like that it could be it since it has sat for six years. Generac won't give me any info beacause i'm "not a servicing dealer". Is any one aware of the proper flashing procedure for this unit?

Manufactures that design and build a product and then will not stand behind them and freely exchange troubleshooting procedures is a disgrace. Any product engineer should be able to tell you in just a few words on how to do this simple procedure. I have done it on other gensets and they are all different. But the same. So I would be afraid to give you any advice as you potentially can harm the unit. Do you have the manual? Whats the model and serial number?

Try this: http://www.dieselduck.net/machine/03%20electricity/flashing_generator.htm

It has been over 15 years since working with small generators, however the Generacs generally used encapsulated modules for different functions. If the unit you are working has this type of construction, try unplugging and replugging the various modules. It is possible that the voltage regulator module has oxidized contacts.

One way to demagnetize the field, is to stop the prime mover with the generator under load.

Larry C

What do you mean by "stopping the prime mover"?

Model 0044560
S/N 3587051

A generator has two parts, the generator which makes electricity and the "prime mover" that turns the generator. Prime movers are usually gas or diesel engines but can be steam turbines, windmills, etc.

I just talked to tech support again. They stand firm that they won't give any info because of liability. However he did tell me that this unit does not have a magnetized rotor. It magnetizes everytime that it starts. I pryed on him a little and he said it could be the voltage regulator since it has 18 VAC L-L. Anybody agree?

Thanks. I have never heard that term before.

Well, I had mentioned a bad field connection. The voltage regulator drives the field. Of course, the engine speed control (governor) provides frequency control. You did make sure that your 18 VAC was @ 60 Hz, I hope. Some gensets have an idle speed switch input on the speed control module.
Joe

Well, turns out it was simply a wire on the voltage regulator. It looks like it didn't get crimped good from the factory. I replaced the terminal and all is good.