Shut down with solid overspeed light

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kyf301
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Sun Oct 06, 2019 1:16 pm

Generac Mo. 04079-3 10 kw. Nat. gas Solid overspeed light. Unit has ran fine since my last post. I had this problem several years ago and gave up on the generator. It sat until I decided to get it running this year. It has ran fine once the fuse blowing problem was fixed. Now this morning I fired it up and ran for 3 min.'s and it shut down with solid overspped light. Now It shuts down right away everytime. Need some help.
Chris
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Sun Oct 06, 2019 6:52 pm

What is the voltage output and frequency during the time it will run?
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kyf301
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Mon Oct 07, 2019 6:18 pm

Their would be no voltage because I'am running it with no load. It would not run long enough to get voltage and frequency readings.
Chris
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Mon Oct 07, 2019 8:48 pm

Voltage output has nothing to do with the load on the unit. It should make voltage immediately when first started up.
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kyf301
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Thu Oct 10, 2019 12:59 pm

When first started the voltage shot up to 270 volts, and then stabilized around 260. I do not have a frequency meter, but ordered one. Will post results as soon as I get it.
Chris
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Thu Oct 10, 2019 2:03 pm

That's a bit high, makes me think the unit is in fact running too fast!
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kyf301
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Thu Oct 10, 2019 3:35 pm

What would make the unit run to fast? Is their a adjustment for that purpose?
Chris
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Thu Oct 10, 2019 7:25 pm

Yes, this unit has a mechanical governor. It may be sticking or just misadjusted. There's a large spring and adjustment knob almost staring you in the face near the front of the engine. Tighter = faster.
Generac tech for over 12 years. I'm here to help!
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kyf301
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Fri Oct 11, 2019 12:28 pm

While I was trying to figure out why it was running to fast, all of a sudden it stopped producing electricity. Is their something that energizes the generator so it can produce power.
Chris
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Fri Oct 11, 2019 2:08 pm

We need to start with one problem at a time, because we might be creating another...

You NEED to know what the output Hz is to determine if it's actually running too fast, or if the voltage is just too high... If the voltage is too high, it can trip the AVR's DPE breaker which will cause a no-output condition until the breaker resets and the unit is restarted the next time.

If the HZ is normal, but the voltage is just too high, I'd suspect the AVR is bad since high generator output voltage is a fairly common sign of a bad AVR.
Generac tech for over 12 years. I'm here to help!
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