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Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: Mark... on December 11, 2012, 06:38:49 pm

Title: Generator load
Post by: Mark... on December 11, 2012, 06:38:49 pm
During the summer while driving I can exercise the generator with a decent load by using the AC.  In the spring and fall I can use the AC heat pumps with the outside temps in the 40s or 50s.  But what about when the temps are in the 30s or colder.  What is the best way to put a load on the generator while driving in the cold?
Title: Re: Generator load
Post by: wolfe10 on December 11, 2012, 06:42:45 pm
Space heaters.  Water heater element if fit.  Block heater.
Title: Re: Generator load
Post by: Mark... on December 11, 2012, 06:46:41 pm
Brett - Never would have thought of using the block heater with the engine running.
Title: Re: Generator load
Post by: wolfe10 on December 11, 2012, 06:57:18 pm
Mark,

If it is too cold for the heat pumps, I PROMISE the radiator can get rid of the 1000 to 1200 watts of heat produced by the block heater.
Title: Re: Generator load
Post by: Mark... on December 11, 2012, 07:01:28 pm
Thanks Brett!  Then that is a really simple way to exercise the genny with a load, in cold, rolling down the road.
Title: Re: Generator load
Post by: Michelle on December 11, 2012, 07:02:49 pm
Use the convection oven to bake cookies.  Win-win :D
Title: Re: Generator load
Post by: John S on December 11, 2012, 07:29:48 pm
Lots of time in the winter I will boondock at a rest area while on my way to a location.  If so, i usually will start the Genny before I go to bed. It will run the aquahot on electric and diesel as well as the battery charger and the lights and the block heater if I put that on too as well as the fridge that will switch to electric.
Title: Re: Generator load
Post by: wolfe10 on December 11, 2012, 10:29:31 pm
Wait, stop!  Michelle WINS! The BEST answer.
Title: Re: Generator load
Post by: Barry & Cindy on December 11, 2012, 11:26:34 pm
We don't use roof air conditioners for heating because an inexpensive small space heater does a better job, while 'saving' or extending the life of the roof air for something only it can do, which is to cool us down in hot weather.
Title: Re: Generator load
Post by: Roland Begin on December 12, 2012, 11:13:54 am
Don't bake cookies but I do bake a bread a week and that exercises the genset nicely.

Roland
Title: Re: Generator load
Post by: Michelle on December 12, 2012, 11:59:28 am
Wait, stop!  Michelle WINS! The BEST answer.

 :))  I didn't think it was a contest...  but...

I'd also thought a pan of lasagna (usually takes an hour, and dinner would be ready when you stop), but one bad bump while driving and you'd be facing lots of challenging oven cleaning (or worse if it pushed the oven door open). 

I do have to give credit for the inspiration to Tom (txforetravel) who would refer to enroute cookie baking as "in flight services" ;)

Michelle
Title: Re: Generator load
Post by: Mark... on December 12, 2012, 12:37:03 pm
I do the driving so I'll have to persuade Mary to experiment with "in flight services"!  Cooking that is...  To be on the safe side, this blockhead will just stick to the block heater option.
Title: Re: Generator load
Post by: lgshoup on December 12, 2012, 09:27:00 pm
OK Lasagna and cookies...where in the world is Michelle parked???
Title: Re: Generator load
Post by: Dave M (RIP) on December 12, 2012, 09:45:55 pm
Generator, gee it you run it for any reason for 10-20 minutes a week, that would be plenty exercise for it, now if you can put a load on it too, that is even better but not real high on the required list as sooner or later you will be loading it down to 30-60%, that is enough to keep the engine is good condition IF it is in good order to begin with.
Dave M
Title: Re: Generator load
Post by: Mark... on December 13, 2012, 09:14:07 am
Generator, gee it you run it for any reason for 10-20 minutes a week, that would be plenty exercise for it, now if you can put a load on it too, that is even better but not real high on the required list as sooner or later you will be loading it down to 30-60%, that is enough to keep the engine is good condition IF it is in good order to begin with.
Dave M

Dave - We spend about half the year on the road - a month or 2 at a time - so during those months running the generator is not a problem and now I have some options on how to create a load in the cold weather. 

However when the coach is in storage, running the generator weekly is not an option.  The best I can do is monthly exercise.  What would you recommend for generator exercise under those conditions? 
Title: Re: Generator load
Post by: wolfe10 on December 13, 2012, 09:40:07 am
I will suggest a different answer to the "how much load" you should have on a generator when running it for "exercise".

All generator manufacturers I am aware of recommend 50% or so load when exercising the generator. 

The reason is the same as you not starting your car (or motorhome) and letting it just idle in the driveway for "exercise". Particularly on a diesel, it is not possible to get the OIL (vs just coolant) up to temperature at idle.  Only under a load does the crankcase get up to operating temperature to get rid of the moisture.

BTW, same reason we run the sailboat engine IN GEAR at 1600 RPM when exercising it at the dock (Kubota 4 cylinder).
Title: Re: Generator load
Post by: Dave M (RIP) on December 13, 2012, 11:40:12 am
Yup, that is exactly why we all have opinions, some  good, some guessed, some with experience and some without. In the end, you have to do what makes you the happiest and smile ;D
Merry Christmas
Dave M
Title: Re: Generator load
Post by: Keith and Joyce on December 13, 2012, 11:49:34 am
When we exercised our generators - large whole facility ones - we ran them at full load for one hour once a week.  These were mission critical units.  Smaller ones just need a good load and run at operating temperature for long enough to heat up and dry out the components.  I have a AT&T switching office across the parking lot from my business and they also do the one hour thing.

Keith
Title: Re: Generator load
Post by: nitehawk on December 13, 2012, 10:21:39 pm
Our coach is in storage 17 miles away but I wonder about the following: Do all the RV dealers go out and "exercise" the generators and drive engines each month? Or do they let the coaches sit and then let the poor, unknowing buyer deal with the nonexercised, abused coach?
Title: Re: Generator load
Post by: Dave M (RIP) on December 13, 2012, 10:30:39 pm
Of course no.
Title: Re: Generator load
Post by: Chuck Pearson on December 14, 2012, 12:56:35 am
I maintained the electrical gear for the lab, part of that was a 471 Detroit powered genset.  It sat in a somewhat damp, salty, unconditioned concrete room day in day out for at least 20 years, only starting when there was a power failure.  When we renovated the space and improved systems we had a load bank test on the genset, it was in near perfect shape as was the engine.  After renovation I put the same genset on an autostart that would fire it off and it would run unloaded, full tilt boogie every Monday morning.  There was no load bank and impractical to load thru transfer switch because it would reboot hundreds of computers, mass specs, subzero freezers and the howls of agony from the scientists would have been deafening.  It's now 30 years old and still going strong.  Based on this experience I don't worry too much about monthly starts on the coach.  I guess if you're really concerned and have electrical service a thermostatically controlled block heater would keep the engine warm and dry inside.

Chuck