Generator Maintenance

[IsleDog]

short answer: run them with a load for about 30 minutes once a month and keep an hour/run time log and maintenance log. without a load is ok but try to get them to operating temp. exercise your transfer switches as well.

[BRinSCupstate]

I think it’s a good idea to run with a load. I have a portable generator for the house and general use. I pulled it out to use one day and it started fine but produced no voltage. I found it had a capacitor go bad in the excitation circuit. Replaced and it was all good again. I doubt the load would have saved the capacitor but I might have known it wasn’t generating power and could have repaired it before I needed it.

[BehindBars]

Originally Posted by ChrisParise

This forum does have a link to manuals but I've never found them using my Android phone search engine, maybe it's me, possibly because its on the full version of the forum only available via a tablet or a laptop, idk, for me it doesn't matter.

I realize it veers off topic, but your comment about the full version of the forum interested and surprised me. I always view the full version of the forum on my older, small screen iPhone using DuckDuckGo. It looks just like the screens on my desktop computer, and all the information is there. I use the full version no matter on what device or computer I view the site

[ChrisParise]

Originally Posted by BehindBars

I realize it veers off topic, but your comment about the full version of the forum interested and surprised me. I always view the full version of the forum on my older, small screen iPhone using DuckDuckGo. It looks just like the screens on my desktop computer, and all the information is there. I use the full version no matter on what device or computer I view the site

Not surprised. Windows likes Windows. That's the IT guy in me. [emoji2]

Sent from my SM-A505U1 using Forest River Forums mobile app

[vlamgat]

Gas motors usually can be neglected more easily than diesel. But the reverse is true with respect to fuel. But both need to have moisture and corrosion eliminated from the windings and coils of the generator and that only comes with use and heat. The GAP is to allow the generator oil to warm up which takes 10 minutes; unit for 15 to 20 mins depending on ambient under load of at least 50% to get heat into the windings; and then run under no load for 5 to 10 minutes.
It's true gas motors do not have to be run but the generator needs to be exercised if you plan to keep the coach long enough to benefit from the longevity this process promotes.
The manufacturer suggests monthly but I don't know and have never seen anything to substantiate that but know that in a marine environment the rust sets in very quickly and monthly may not be often enough. In a dry UT or AZ environment I suspect you can get away with it every 4 to 6 months.

[jacques1543]

At a forest river rally they had a session on care of generators and the trainer said to run them once A month for 30 to 60 minutes….60 was better.

[dlambers]

I worked Generator Maintenence in the Air Force for 16 yrs, so I might be able to shed some light here.

Two hours, once a month while under load is a great regimine to follow. Running it like that couses the windings in the generator the make the voltage to warm up, driving any absorbed moisture out of them. Excessive buildup of moisture in the windings can accelerate insulation breakdown and lead to generator failure in the future. It also helps keep the engine in good shape, just remember to change the oil no less than once a year or every 100 hours of operation.

[BehindBars]

It seems most advice centers on driving moisture out of the generator’s windings. I have yet to see on this forum, or elsewhere, that a generator owner reported a failure, and the failed part was the electrical generator/windings itself. Those who “neglect” their generators are apparently lucky.

If moisture in the generator is the problem to be avoided, the environment in which the generator is stored would be a big factor. Rather than blanket advice about running the generator at certain prescribed intervals, I think the practice should be tailored to individual situations. Examples af varied situations would be a generator stored in a dry climate and in a climate controlled building, vs a generator stored outdoors seaside.

[BehindBars]

Originally Posted by kenandterry

This proposal for starving the generator is interesting, although in years so far, I’ve always been successful with fueling with a good percentage of Stabil, filling the tank, and then running the engine and generator for at least 15 minutes to circulate the mixture, before shutting down for winter.
Do you happen to have photos of the shutoff valve installation?

In the past I bought and used Stabil, but now I rarely use it. I had no problems using it, but I also have no problems not using it, so it seemed like a waste. In the case of a carburetor, whose bowl is vented to the atmosphere, I don’t believe Stabil can prevent the volatile fuel compounds from evaporating and leaving behind gunk.

I just ran the generator out of fuel this morning by closing the shut off valve. I can’t remember if my Sunseeker’s generator has an easily accessible float bowl drain, but if so I will drain the remaining gasoline that may be in the carburetor float bowl. I will not run this generator again until the next camping trip, which may be 4 months away.

As requested by Ken, attached are photos of the added fuel shut off valve, shown in it’s open position, as seen from the underside of the Sunseeker’s 4kw generator.

[ilmor]

Originally Posted by Chili46

We've read several places that when the generator is not normally used it should be run, with a load on it, for anywhere from 10 mins to 2 hours per month. What is Forest Rivers recommendation? Personally, I feel that 2 hours is excessive and my wife thinks that 10 mins isn't enough.

It would be a generator manufacturer recommendation, not a Forest River reccomendation, that you should adhere to. The answer is found in your (typically Onan) operation manual.

[vlamgat]

Originally Posted by jacques1543

At a forest river rally they had a session on care of generators and the trainer said to run them once A month for 30 to 60 minutes….60 was better.

But as I posted and others have too - running them is not enough. You must load them to build heat in the windings. After 30 minutes there diminishing returns especially in warm ambient temperatures.

Nobody has evaluated what is best, ideal, optimum, minimum or maximum effective. What we do know is that those who have had a generator from new for many years (say >10), done reasonably regular oil and (especially) filter changes, have had fewer needs to call in factory reps for repairs. At least this what the OEMs and their affiliated shops tell us.

In addition the US, UK, Aus and a few other militaries have had to mothball generators (as part of other equipment) for long periods and have discovered that unless their inhibiting process is carefully done, they are better off exercising the generators along the lines discussed here rather than hoping for an immediate function when reactivated.

[Mandog]

The goal when exercising the generator is;
1. To excite the circuitry. This used to be important with rotor/stator windings in generators.
2. If gas or diesel driven to exchange the fuel in the carburetor with new from the tank or in a diesel to exchange the fuel in the injector pump, lines and injectors.
3. To have the engine at operating temperature for a minimum of 20 minutes to burn off any moisture accumulation in the oil and crankcase.

Running short periods of time 15 minutes or less can actually build more moisture in the crankcase. Propane generators are great for being able to set for extended periods of time without needing any run time. I also feel running them helps the pests stay away a little better.

[BehindBars]

Originally Posted by Mandog

The goal when exercising the generator is;
1. To excite the circuitry. This used to be important with rotor/stator windings in generators.
2. If gas or diesel driven to exchange the fuel in the carburetor with new from the tank or in a diesel to exchange the fuel in the injector pump, lines and injectors.
3. To have the engine at operating temperature for a minimum of 20 minutes to burn off any moisture accumulation in the oil and crankcase.

Running short periods of time 15 minutes or less can actually build more moisture in the crankcase. Propane generators are great for being able to set for extended periods of time without needing any run time. I also feel running them helps the pests stay away a little better.

Your comment that propane generators can “set for extended periods of time without needing any run time” seems to contradict your reasons for needing to run a generator. What about exciting the circuitry? What about burning off oil and crankcase moisture? Propane generators still have circuitry, still have oil and a crankcase.

[ferrisjc]

Have tried to maintain the 2 hr maintenance window on a monthly basis for Onan Generators using a 1/2 to 3/4 draw but at times this has been difficult. Have performed checks and drained the oil as prescribed and maintained the best operating conditions. BLUF: I feel three effective maintenance windows with a two hour duration at above conditions would be sufficient for a year. Have had to rely on the generator a few times over the past three years and was thankful it performed without any problem.

[mnoland30]

The generator in our houseboat went out and wasn't replaced for 3 years. The manager put Stabil in the 50 gallon gas tank every year. When we installed the new generator, it started up and ran just fine on 3 year old gas.

Seafoam is another great gas treatment. I've injected into the carburators on generators that wouldn't start and they start right up.

[BehindBars]

Originally Posted by mnoland30

The generator in our houseboat went out and wasn't replaced for 3 years. The manager put Stabil in the 50 gallon gas tank every year. When we installed the new generator, it started up and ran just fine on 3 year old gas.

That’s good but there is no control group in the experiment. What if a twin generator started up and ran just fine, or didn’t, on 3 year old untreated gas? Then we would prove whether the Stabil was worthwhile, or suggest that it was a waste and did nothing.

[PDFOR3]

My Sunseeker (propane generator) is stored outdoors under a carport. Is it safe to be inside the motorhome while exercising the generator? I have always stayed outside while exercising the generator. Is this necessary?

Yes, I know I can move it from under the carport, which I usually do.

[John in OkieLand]

Originally Posted by PDFOR3

My Sunseeker (propane generator) is stored outdoors under a carport. Is it safe to be inside the motorhome while exercising the generator? I have always stayed outside while exercising the generator. Is this necessary?

Yes, I know I can move it from under the carport, which I usually do.

That would depend on where the Exhaust for the generator is, relative to the motorhome and the wind conditions at that time.


If the wind would blow the exhaust away from the coach, you would be just fine inside the coach.

[NMWildcat]

If it is an open sided carport, I don't see the concern. And your RV does have a CO alarm.

[PDFOR3]

Yes, I do have a CO alarm. Here's a photo of storage facility. Now there is a Class A parked on my passenger side.