# Older generac generator problem



## hpaulb (Jun 15, 2014)

Anyone shed some solution to this? Older generac9202-1 5.2kw. Low use. Engine runs well and trying to get through the generator tests. If I hot wire the rotor winding to 12 volts, output is about 80 Vac as it states in the manual but only is i keep it conected. Is the stator only supposed to have voltage aplied juring startup? Anyone know anything about these generators? Also manual says the resistance is 15.5 ohms. I read 65 ohms?


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## aandpdan (Oct 8, 2012)

> Is the stator only supposed to have voltage aplied juring startup?


I think you mean the rotor. No, the rotor needs voltage at all times to generate the magnetic field that induces current flow in the stator.

Check the brushes. The springs may be weak/broken. How are the slip rings?


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## hpaulb (Jun 15, 2014)

Measuring the resistance on the two contacts gives 65 ohms. That would be the conections, carbon brushes and slip rings. They look a little worn. Don't know where to get any parts like new brushes. They do apply presure. You can tell when you put them back in.


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## aandpdan (Oct 8, 2012)

Measure the resistance on the slip rings themselves. The brushes do have some resistance.

How dirty are the slip rings? They should be clean and bright.

Does the unit have a voltage regulator?


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## hpaulb (Jun 15, 2014)

Slip ring direct measurement is 17 ohms. They look a little darker than copper should. Direct hookup to battery gives the generator ~ 80 vac output. There is a regulator but have no idea how to check it. Does the amount of voltage on the rotor deturmine the ac output? Manual says the rotor field boost comes from the DC control module (Block diagram shows a resistor and diode that lights up on startup then goes out?) then goes to the regulator block and the rotor rings. Not sure how it regulates?


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## aandpdan (Oct 8, 2012)

Yes, the voltage on the rotor determines the output voltage. The regulator controls that.

More load = higher voltage.

Do you have the service manual? It walks you through all the tests and it looks like you'll need to do them. Odds are the regulator is at fault but it's only by eliminating the rest of the system can you be sure.

To quote the manual "It is very difficult, if not impossilbe to test a voltage regulator in the field."


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## hpaulb (Jun 15, 2014)

Anyone sell used ones or new at a good price?


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## SpringerPop (May 25, 2014)

They're all over eBay, but you'll have to know a bit about yours to select the proper replacement.

The quality varies all over the place.

Pop


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