Why is the generator cycling??

A generator will vary in speed based on electrical load. The alternator is trying to maintain the correct 60hz frequency needed for American standards. When an A/C is turned on, a mechanical resistance to the engine is created due to the magnetic resistance created in the rotor. The engine governor adds throttle to compensate for the drop in RPM.
3600 Rpm = 60 cycles per second. If the frequency drops the current (amperage) builds up along with heat. When the alternator reaches 3600 RPM voltage and frequency will be correct.

wa8yxm wrote:
How frequent is the cycling. Nobody has ask that.
Running up and down every second is the air/fuel mix (Carb setting) on a gasoline generator

Running at low amprage for oh say 20 hours then Kicking up.. Progressive Dynamics Charge Wizard

Running low for oh say an hour then kicking up usually about 3 amps. Fridge auto switched to AC

There are more options too. (not sure of the fridge cycle time)

Its a Diesel Generator, not gas.

How frequent is the cycling. Nobody has ask that.
Running up and down every second is the air/fuel mix (Carb setting) on a gasoline generator

Running at low amprage for oh say 20 hours then Kicking up.. Progressive Dynamics Charge Wizard

Running low for oh say an hour then kicking up usually about 3 amps. Fridge auto switched to AC

There are more options too. (not sure of the fridge cycle time)

Check the status of the Inverter/Charger while it's happening. It's probably charging your house batteries.

converter

supercub wrote:
I have an Onan 7500 diesel generator. With a Xantrax 2000 watt inverter/charger. It cycles every couple of minute. I've let it run for a couple hours, batteries are charged, so I'm assuming it's the charger that is cycling. I wasn't aware while charging the charger would cycle, why is that?

Because you are using 12v's somewhere (lights, CO detector, radio memory). You're water heater will turn on and off too, as needed, causing the genset to rev every so often. If it bothers you, put a constant load on it like so many have said.

I have an Onan 7500 diesel generator. With a Xantrax 2000 watt inverter/charger. It cycles every couple of minute. I've let it run for a couple hours, batteries are charged, so I'm assuming it's the charger that is cycling. I wasn't aware while charging the charger would cycle, why is that?

What your are experiencing is call "lean roll".
If you have a fuel mixture screw on the bottom of the float bowl, give it a 1/4 turn out and see what happens.

Richard

If its a basic gasoline RV generator its probably the carb/fuel/air filter or the governor. If it runs smoothly with a load check the governor setting, verify its putting out 120 plus volts at 60 hertz with a digital volt meter with the hertz capability. You can get cheap meters off Amazon for less than $50 and check it yourself. Generators don't like light loads, so if it runs fine with the A/C you probably just need to set the governor rod to 62 hertz. That usually gives you 126 to 130 volts with no load. With a light load it will always stumble occasionally, especially the smaller generators. The single cylinder 4KW models are glorified lawn mower engines, the V-twin 5500 types run smoother though, but they don't run any better than my John Deere riding mower either.

What type of generator? Gas/Diesel, inverter, built in/portable, etc... (exact model would be best)
What are you defining as "cycling"? Every 2-3 seconds or every few minutes?

If it's a carbureted gas inverter generator, could be a gunked up carb. This would be a continuous cycling every few seconds.

Or if it's reving up every few minutes, it's likely an intermittent load. Battery charger, water heater would be common items that you wouldn't hear kick on but would add a load causing the generator to apply more power.