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Kohler - unsteady voltage


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  #11  
Old 12-22-2018, 01:33:16 PM
Birken Vogt Birken Vogt is online now
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Default Re: Kohler - unsteady voltage

I almost never replace brushes on these even though some people run them off grid and thousands of hours.

Hours is the only thing that matters to the brushes, age does not harm them.
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Old 12-22-2018, 02:41:42 PM
Trekrider2001 Trekrider2001 is offline
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Default Re: Kohler - unsteady voltage

I did the load test with the space heater. I measured the voltage with a digital meter and the voltage jumped around between 120 or so and then down to 100 or so. Obviously, it was not constant. Adding the space heater load caused the voltage to bounce between the high 90's to 119 or so. I turned on the TV to try and simulate the big light flickers of the other night, but I could not. Mild dimming only. Mind you, during the power failure the generator had been running for at least 5 hrs (so very warmed up) while my test today was only about 15 minutes. Birken suggests that the brushes are not worn (not after 280 hrs). Maybe they get dirty or coated? If I take them out how do I clean them? With some emery cloth? What about cleaning the slip ring?
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Old 12-22-2018, 03:59:29 PM
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Default Re: Kohler - unsteady voltage

Is the variation rythmic or chaotic?

Using some ideas from the other thread, you might try feeding 24v into the brush circuit and see if it still happens or is stable then.
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Old 12-22-2018, 08:32:29 PM
Trekrider2001 Trekrider2001 is offline
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Default Re: Kohler - unsteady voltage

Is the variation rythmic or chaotic?
hard to tell with a digital volt meter but I would say rythmic.
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Old 12-22-2018, 09:30:17 PM
Zephyr7 Zephyr7 is offline
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Default Re: Kohler - unsteady voltage

The slightly lower voltages seen with the heater running relative to not are probably due to volt drop in wiring. Seems like the generator is causing the problem regardless of the type of connected load.

Might be corrosion in the slip rings, but that should make more of a noise and less of dimming issue (they spin too fast for you to really see the issue in lights). As Birken mentioned, the brushes only care about operating hours, not age. However, long periods of idle time with no running can result in corroded slip rings since the brushes are wiping them clean while running.

Since youíre saying the issue is rhythmic, that sounds like an oscillation to me. Is the frequency changing too (youíd hear this change in the engine if you donít have a frequency meter), or is the problem related to voltage only?

Have you checked that there are no blocked vents on the regulator (I think this is a propane or natural gas set, correct?)?

Bill
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Old 12-22-2018, 09:30:27 PM
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Default Re: Kohler - unsteady voltage

A light bulb will give a better idea if it is rhythmic than a meter.
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Old 12-22-2018, 11:30:39 PM
Mark Dieckmann Mark Dieckmann is offline
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Default Re: Kohler - unsteady voltage

Do you have an amp meter? I am wondering if the load changes when the voltage drops. How long is the voltage low? Just a second or three? If so then I would suspect a motor or compressor that is not starting and cycling on and off on the overload protector causing excessive amp draw.
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Old 12-23-2018, 02:13:20 AM
Trekrider2001 Trekrider2001 is offline
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Default Re: Kohler - unsteady voltage

the drops are a fraction of a second. I will do a controlled load test tomorrow. Basically shut everything off in the house except my space heater. That should give me some better information.

Natural gas. And the thought of fuel starvation crossed my mind, but I had the generator plumbed with its own direct line after I had my meter upgraded to a two pound system. The feed to the house is rated at 750K BTU. The house light fluctuation was worse during the power outage and I thought that with the neighbors also running their generators, the mains might have a problem. Basically, on both sides I have neighbors with natural gas powered systems like mine. But that seems like a stretch.
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Old 12-23-2018, 03:08:32 AM
Zephyr7 Zephyr7 is offline
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Default Re: Kohler - unsteady voltage

If your gas company is ok giving you 2 PSI gas service, then itís highly unlikely there is a capacity problem on the gas main.

The regulator has a small vent on it that needs to be clear for the regulator to work. Bugs love to build nests in that vent and plug it up. This is a common thing to check on these units, and itís very easy to fix if clogged. Itís worth checking before digging deeper into the unit.

Bill
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Old 12-23-2018, 07:09:42 PM
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Default Re: Kohler - unsteady voltage

The gas regulator vents are clear. That would have been too easy. I ran a load test. With all breakers in the house off, (except for the plug I was using to measure things), the generator was putting out 119 - 120 volts. I added the space heater load (+1500 watts) and the voltage dropped to 118 - 119. I added the oven and it dropped to 117. Then I added the TV and the voltage went unstable with drops to 90 volts. There was no real cause and effect that I could re-create. Turning the space heater on and off would not trigger the drop outs. The oven was not on long enough to cycle on and off. So it is clear, as the load increases the voltage becomes unstable. Does this give us a clue as to what is wrong?
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