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Generator changes speed, what's going on?

supercub
Explorer
Explorer
My 04 Revolution has a 7500 Watt Onan Generator. When operating the generator and running the TV, direct tv box, refrigerator and 2 interior lights, and behind the scene equipment, the generator will vary it's running speed and associated noise level. As it changes speeds, the battery stage indicator lights on the Xantrex indicator will change from full battery, to low, to med, and continue this sequence as the speed of the generator changes. It will run on each stage for several minutes, and then shift to the next, with no apparent change in power being used. It continues this cycle the whole time I'm running the generator, over and over. I also get an overheating light on occasionally.
What is causing the generator to keep changing speeds?
What is causing the overtemp light to come on?

Thanks
11 REPLIES 11

Ivylog
Explorer III
Explorer III
Chris Bryant wrote:
I believe the OP has it backwards, the Xantrex is switching the charger on and off- this is the load that is changing on the genset. Disable the charger for a test, I bet the genset stays constant.

X2 Sounds like you have a charger problem that the generator is sensing...changing speed.
This post is my opinion (free advice). It is not intended to influence anyone's judgment nor do I advocate anyone do what I propose.
Sold 04 Dynasty to our son after 14 great years.
Upgraded with a 08 HR Navigator 45’...

Chris_Bryant
Explorer
Explorer
I believe the OP has it backwards, the Xantrex is switching the charger on and off- this is the load that is changing on the genset. Disable the charger for a test, I bet the genset stays constant.
-- Chris Bryant

siggyd777
Explorer
Explorer
" Son of Norway" has the correct answer !
Siggy
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MrWizard
Moderator
Moderator
yes the load is changing
your fridge is cycling on/off and maybe the water heater is too
I can explain it to you.
But I Can Not understand it for you !

....

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Son_of_Norway
Explorer
Explorer
Put a meter on the generator to check voltage output and frequency. Put a clamp-on ammeter on one of rhe output wires to check for changes in load. That will give you your answer.
Miles and Darcey
1989 Holiday Rambler Crown Imperial
Denver, CO

wallynm
Explorer
Explorer
The refrig load varies and is not the same continuously. The AC compressor may be vary the load requirements based on the temperature setting. Onan design to vary the RPMs based on load. Other generators run a constant speeds.
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supercub
Explorer
Explorer
If something is turning on and that's the reason it's changing speed, due to load demand. Why is the indicator on the xantrax, showing low battery, then switching the battery icon showing 1/2, and then the icon showing full (which I believe is float charge)? It continually goes through this cycle. I would think if the batteries are fully charged, and a load is increased, the generator might change speed to increase output, but the battery indicators (icons) should remain at full charge.

ncrowley
Explorer
Explorer
The generator changes depending on the load it is under. If you are sure the load is not changing, then there is probably something wrong with the generator.
Nancy
Newmar Northern Star

Yosemite_Sam1
Explorer
Explorer
Bruce Brown is spot on.

Or the fuel line need flushing. Or the filter needs cleaning or replacement.

2edgesword
Explorer
Explorer
Bruce Brown wrote:
You have an inverter type generator, it varies speed depending on the load. It's working as designed.


I was thinking this also but when he said "with no apparent change in power being used" I was assuming he meant it wasn't happening as a result of changes in load.

Bruce_Brown
Moderator
Moderator
You have an inverter type generator, it varies speed depending on the load. It's working as designed.
There are 24 hours in every day - it all depends on how you choose to use them.
Bruce & Jill Brown
2008 Kountry Star Pusher 3910