How do rv/marine generators behave overloaded?

[mesquito_creek]

Friday night my wife was down in the cabin making dinner. My oem Koehler 5k was running and all kinds of stuff was going on. Stereo with amps, AC was running and she was on the stovetop, could have been microwaving? Who knows? I was out back on the swimming platform and the generator went from the normal hum/accelerate etc into a erratic chugging/dieing/choking out sound but never actually quit. I told her to back off some appliances and thing returned to normal. So it that the normal indicator for overloading? Should there be an automatic deal somehow that protects the generator etc? Could it be a sign of something else wrong with the generator or batteries?

 

[Meaney77]

Friday night my wife was down in the cabin making dinner. My oem Koehler 5k was running and all kinds of stuff was going on. Stereo with amps, AC was running and she was on the stovetop, could have been microwaving? Who knows? I was out back on the swimming platform and the generator went from the normal hum/accelerate etc into a erratic chugging/dieing/choking out sound but never actually quit. I told her to back off some appliances and thing returned to normal. So it that the normal indicator for overloading? Should there be an automatic deal somehow that protects the generator etc? Could it be a sign of something else wrong with the generator or batteries?

In all my years of camping I have never overloaded a 5K generator unless trying to power a large air compressor to fill tires. Usually the circuit that overloads will trip. Sounds like you have something else going wonky might check the converter/charger unit or batteries. I know weird things can happen if you have 1 defective battery.

 

[pronstar]

It should pop the main breaker then simply idle because of no load...that's how mine reacted anyway.

 

[racered]

Sounds like a lack of fuel under load. Change fuel filter, check fuel supply volume or lack of at carb.

 

[BoatCop]

Mine (Onan 7K) has an electrical management system that sheds (shuts down) components when over loaded. Usually one of the A/C compressors. It prevents both compressors from coming on at the same time, but will allow them both to run, as long as the load is within specs.

 

[BigSteve]

I have delt with gen sets installed on Semi trucks for years
Same basic units
Yes, you can overload them by running out of fuel or shuting them off while under load.
Wipes the generators rotor out
Like posted earlier check your fuel filter first

 

[69 1/2]

Your Kohler 5.0 is a Kawasaki 2 cyl V configuration. They EAT spark plugs, and impellers for that matter. If the plugs have more than 60 hrs they need replaced. Easy job and it will run perfect again. The impeller goes out at 100 hours. I carry spares for both.

 

[Uncle Dave]

You are lucky if they pop a breaker- most start to stutter and brownout which is hard on your appliances. (kind of like what you are describing)

Starting the AC compressor is the hardest thing they do - and a hard start kit is always a cheap investment Microwaves , convection oven combos along with hair dryers really hit it hard.

UD

 

[mesquito_creek]

You are lucky if they pop a breaker- most start to stutter and brownout which is hard on your appliances. (kind of like what you are describing)

Starting the AC compressor is the hardest thing they do - and a hard start kit is always a cheap investment Microwaves , convection oven combos along with hair dryers really hit it hard.

UD

Obviously I am going to check of few of the things mentioned above that are simple enough to perform the maintenance on... But I am leaning toward this overload condition. It is very likely that the AC would be running, along with the refrigerator and when she went for the double burner electric stove that was just too much! The battery AC converter would have been on also as soon as the genny was fired up and the house battery will always take a charge after floating around a couple hours with stereos/water pump and the vacuflush head getting used. I recently replaced my fridge with a 120V only unit as a quick fix, but I need to order a proper 120/12VDC and shed that additional compressor off the 120V side of the house when only running on the generator out on the lake at night...

 

[pronstar]

Anything with an electric heating element is a massive current draw.

 

[Uncle Dave]

Obviously I am going to check of few of the things mentioned above that are simple enough to perform the maintenance on... But I am leaning toward this overload condition. It is very likely that the AC would be running, along with the refrigerator and when she went for the double burner electric stove that was just too much! The battery AC converter would have been on also as soon as the genny was fired up and the house battery will always take a charge after floating around a couple hours with stereos/water pump and the vacuflush head getting used. I recently replaced my fridge with a 120V only unit as a quick fix, but I need to order a proper 120/12VDC and shed that additional compressor off the 120V side of the house when only running on the generator out on the lake at night...

Yeah- you can't run all that off 5K. You are oversubscribed.

Especially a dual compressor fridge A/C unit start scenario.

Just add it up

- if its hot out (95 or better) take off 10% (500 watts) if its out. at 3000 ft take another 7% off the top.

Air cooled carbed RV gensets are dinosaurs with very predictable behavior.

I deal them a lot in my pet grooming business.


UD

 

[mesquito_creek]

Just a follow up!! 2 spark plugs and an impeller! Ran it hard for two days at the lake!... Like a boss...

 

[TCHB]

Microwave and electrical cooking can draw a huge load if they start at the same time. One of the problems is that when things start at the same time the load is very high for a short time which will trip the generator.

 

[River Runnin]

Getting low on coolant and or oil will make for erratic operation before full on shut down!

 

[Uncle Dave]

Getting low on coolant and or oil will make for erratic operation before full on shut down!

Correct -

Onan have oil level shutoffs and the killer combo is being just a tad low - plus parked on a bit of slant.

and yes a 1750Watt Magnetron cycling combined with a an air conditioner compressor startup will flatten a 5K.

 

[Strabo]

Normal fuel consumption on our onan 4k with comfy temps outside is 3 hours per gallon. Temps over 100 with AC running is a whopping 1 gallon per hour. Amazing. I dont run anything but the ac unit in hot temps, fridge is on propane.

 

[Uncle Dave]

Normal fuel consumption on our onan 4k with comfy temps outside is 3 hours per gallon. Temps over 100 with AC running is a whopping 1 gallon per hour. Amazing. I dont run anything but the ac unit in hot temps, fridge is on propane.

I had a toy hauler with a micro quiet 4000. running it was like a construction project right outside my front door.

It was tied into my haulers 20 gallon onboard fuel station, but a couple days running an AC unit starts to really dent your supply.

The onan 4K is a noisy 3600 RPM hog but should do a bit better than that - its spec is like .3 no load(idle thats right 1/3 GPH just to idle) .5 (half load is 1 13.5KBTU Ac after it starts) .75 full load.



I ignored its existence entirely and put a yamaha 3000 in the back of my truck and used half the fuel every trip and had a much quieter nicer experience.

it doest have a real pressurized oiling system with a filter, just a splash system.

On the plus side-

I could start in from inside and see clearly how much it was drinking.

it does however have an easy altitude adjustment on its carb which is nice.

UD

 

[rush1]

Those micro lite genny's aren't very good and any generator buzzing 3600 rpm's isn't going to last as long as the old school bfa 4000 watt style genny running at 1700 rpm's, the old style genny you have to replace the brushes every so many hours though.