Running Genny While Driving

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jmugs

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Nov 4, 2012
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213
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On the road
I have heard of folks running their genny while driving to use a/c, fridge, etc.

Your opinions please.
 
We run the genny while driving to run the roof top AC when it's hot outside, but that's about it.  When it is on, it does also run the fridge because it is generally set to Auto, but that isn't why the genny is on.

Thanks,
Jeff
 
Using air conditioning on a hill on a hot day works for me - if I have over a 1/4 tank of gas at the time. If in that type of topography, I will make sure I fill when down to 1/2 tank.

Some will use the start switch on the dashboard - having left the A/C on when unhooking prior to a trip. That is convenient and OK if you have been running the genset and it is already warmed. Otherwise, starting a cold Genset and powering the A/C at the same time would not be such a good idea, IMO.
 
Bob, one caveat.... your method is great only if you have an automatic transfer switch. Many older RV's require unplugging the generator from the rigs plug-in and then re-plugging it into the pedestal at the campground.

  Best to shut off the generator then before disconnecting from the rig.

  Is this nitty-picky or the truth ?  ;D

 
Jmugs - Yes, many of us run generators while driving but it's to use the roof A/Cs.  The dashboard A/Cs can't keep a big motorhome cool enough in the summer heat of our southwestern deserts.  Anything else is just a byproduct of it running, such as the aforementioned refrigerator on Automatic and switching from gas to electric when the generator is turned on.

ArdraF
 
We had never done this before but after attending the GNR this past summer, we now do!  We attended a workshop the Onan put on and were told that we are doing our generators a disservice if we don't at least run them once a month.  He said that the best time to utilize this is to run them while driving down the road to run your AC's.  When driving back from Iowa to California we had several occasions where it just got too hot in the MH and the front AC just wasn't working, so we turned on the genie, let it get up to speed and then cranked on the AC!  Worked beautiful!!
 
We always run the generator for the A/C in the south and southwest while traveling.

I can however, by experience, highly recommend shutting down the A/C, then the generator, before plugging into a power pedestal. It can stress your transfer switch, otherwise, and not in a good way to go from generator power to shore power with a load on it.  8)
 
I can however, by experience, highly recommend shutting down the A/C, then the generator, before plugging into a power pedestal. It can stress your transfer switch, otherwise, and not in a good way to go from generator power to shore power with a load on it.

Kim, a good point.  We always do it by stages so nothing is "jolted" too severely.  We turn on the generator, let it start showing a charge on the gauge, then turn on the A/C.  When we get to the campground, we turn off the A/Cs, turn off the generator, plug into the pedestal, let the gauge show it's charging properly, and then turn the A/Cs back on.  Better to be safe than cause an irritating problem.

ArdraF
 
We have had our Beaver for 18 years and the diesel generator has run probably 90+% of the time when we are traveling--151,000 miles so far. We have a 7.5KW ONAN which now has 2983 hours on it and it runs like a top. The only problem we've ever had has been the need to replace the electric fuel pump, twice.

We use it to power the AC when in the warmer climate and the coach electric heat when it's cold. We like to be comfortable.  We have heard on several occasions that you use less fuel and get more efficient AC with the roof air than you do with the dash air. We always have monitored the fuel used and it has consistently been in the range of 0.5 gph.

You've spent the money for the coach. You have the generator, why not use it and be comfortable?
 
Thanks everyone. I was having a "heated" discussion with a friend who contends there safety concerns. I feel that as long as its safe to run while parked there should be no reason it wouldn't be "cool" to use it on the road.
 
carson said:
Bob, one caveat.... your method is great only if you have an automatic transfer switch. Many older RV's require unplugging the generator from the rigs plug-in and then re-plugging it into the pedestal at the campground.

  Best to shut off the generator then before disconnecting from the rig.

  Is this nitty-picky or the truth ?  ;D

Sorry, Carson -- am not sure what you are explaining here.  ???

Once unhooked from shore, plugged into the genset -- and underway, why the need for a transfer switch. On your rig, didn't power come into the converter from your 30A cord, wherever plugged in?  Mine is a '96 Adventurer, how were older rigs set up differently?
 
Our generator also runs 90% of the time we are on the road. Our travels are spring, summer and early fall and, in addition to the roof air conditioners we typically have a crock pot, bread maker, a couple of computers, and a printer operating while traveling. Besides, you do not think the dog would stand still for having to ride on the couch without room air conditioning, do you?
 
Ok, Bob. Guess we are thinking on parallel tracks a bit.  I had a '95 Winnie without a transfer switch.

  I assumed ( a bad word) that you were suggesting that if you were running the gennie until you got to a campground and then immediately plugging it into the CG pedestal without shutting off the genie. Hence assuming again that you expected the power to continue without interruption to feed the RV.

  Obviously something went wrong with my assumptions. (old age)....

  I'll' re-read your post and see where I went astray.  I think you made your point and I can see that the main point is that the genie is still hot and ready to go again after you hook up and then restart it.

I think I got it.  Sorry for the inconvenience.  Life is complicated...  :D

 
carson said:
I assumed ( a bad word) that you were suggesting that if you were running the gennie until you got to a campground and then immediately plugging it into the CG pedestal without shutting off the genie. Hence assuming again that you expected the power to continue without interruption to feed the RV.

Maybe this statement was misleading . . .

I wrote >> Some will use the start switch on the dashboard - having left the A/C on when unhooking prior to a trip.

That probably should have read: Some will use the start switch on the dashboard - having turned the A/C switch on prior to leaving on a trip.

If I was using the A/C under park power prior to a trip -- I would first turn if off. I would then unplug from power, and plug into the genset - then go inside and turn the A/C switch back ON. It would then be ready to start from the cockpit if needed. That's the only time I ever used the dash turn on switch - not many reasons otherwise.

I recall when I rented an RV prior to purchase back in '95, that Class C Tioga had a genset start switch on the dash. It was in the summer and the rental company guy told me how to do that if it got hot outside while going to Reno. He also said that was one of the main reasons they put the start switch on the dash. As in the Adventurers, there is also a switch over the range and on the genset itself - 3 in all.
 
My Beaver owners manual suggests that using the generator to charge the house batteries after a period of dry camping instead of the engine alternator is better in the long run. Heavy loads on the alternator, charging depleted house batteries creates heat which shortens the life of the alternator. In a diesel pusher the alternator is already in an area which is hotter than a front engine rig.

My Onan manual says that it is perfectly safe and prudent to run the generator while driving. I don't recall ever hearing of anyone wearing out an Onan diesel generator such as is found on most large pushers. I have heard of many people who have to replace engine mounted alternators.

Running the house AC and other luxuries are icing on the cake.

Ken
 
I just thought I'd also add that we were also told during our workshop at the GNR that you should always turn the generator on and let it get up to speed and then the A/C or heat.  When turning it off its the same procedure in reverse ;D  They said that you don't want to turn the genie on or off under a load...
 
Ken, that makes sense. Will keep that in mind.

Jim, I'd think people would know that, but I guess there are those who forget where the on switch for the brain is.
 
Bob Buchanan said:
If I was using the A/C under park power prior to a trip -- I would first turn if off. I would then unplug from power, and plug into the genset - then go inside and turn the A/C switch back ON. It would then be ready to start from the cockpit if needed. That's the only time I ever used the dash turn on switch - not many reasons otherwise.

I recall when I rented an RV prior to purchase back in '95, that Class C Tioga had a genset start switch on the dash. It was in the summer and the rental company guy told me how to do that if it got hot outside while going to Reno. He also said that was one of the main reasons they put the start switch on the dash. As in the Adventurers, there is also a switch over the range and on the genset itself - 3 in all.

Bob, I agree that having the gen start switch on the dash is there for the convenience of the driver, but to actually suggest that it is good practice to preset the conditions (i.e. turn A/C unit ON, with no ac applied) so that the gen can be powered up with the load of the ac unit already present, is a little fool hardy.  It certainly flies in the face of all other gen operating advice that I have ever heard.

I'm sure it is more convenient, when traveling alone, to just hit one switch on the dash, but I would suggest stopping and giving the gen time to come up to operating speed and voltage prior to turning ON the A/C unit.
 
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