Cummins Generator's

[KnightEagle]

When we bought our Adv 116DS back in 2017 ran into a problem from day one. Adventure past the buck to Cummins and Cummins passed it onto the EPA. What it was the temp was hot outside so we started up the generator to power the fridge and the AC. Was also dinner time decide to use the microwave and it tripped the Brecker reset it again it tripped. We contacted the dealer about it since we had just bought it. Was told to bring it back in. They ran all the checks and couldnt find anything wrong. Well we kept on with our trip. Again we ran into the same problem and saw a dealer in N. Carolina same results. From then on our trip we had to watch what we had on. Turned out Fridge/microwave or fridge/AC of and the lights. This continued on till Boise Idaho then it started blowing oil out. Had to call a service tech because the cummings dealers tech was out of town. He change the filters plugs and oil and everything else seemed ok. From there had to stop again at a cummins dealer in north Nevada cant remember the towns name they did everything short of changing the unit. After Los Angelas agin had to see the Cummins near Yuma Az check it and found a letter from Cummins that everyone misted There was a change made in 2016 in that model generator that cut the power output to meet air quility to meet the EPA. We had a generator in our other TC the Artic Fox 990 that had the other generation generator. In it could run everything and had to problem.

 

[CharlesinGA]

OK, useless information without the exact model of generator(s) involved. Not just QG2500, but rather, model and spec number from the tag on the unit.

Charles

 

[KnightEagle]

Sorry I didnt meet your god like ideas of a post. It was a direct mention of a fault in the average TC camper generator such as one's found in Eagle Cap, Adventure, Big Foot, etc those that are running on propane not on the pusher's, Hugh diesel rv's and 5th wheels may use larger generators some dont. Not sure if above apply to gas or diesels run generators in rv's

 

[workinonit]

Wow. Kind rude. Charles' point is that from your post we don't have a clue about the generator. Sounds to me like you simply overloaded it. Maybe don't put so much load on it for starters.

 

[KnightEagle]

Yes I was a little rude. Need to realize not everyone has all that info at there finger tips. When dealing with TC there is mainly only one that is used by most all TC builders and that is the Onan propane version 20amp. In order to meet the EPA guide lines they drop the breakers down to 20 amps from 30 amps. It was the same one we had in our Artic Fox yet it had a 30 amp. I ask Cummins why the change and it was the EPA. For it was a cheap fix on there part In the Fox was able to power the A/C, fridge, Micro wave, all lights, water heater and a lot more wasn't even trying to overload till I tryed to kick in the elec chain saw. They are very tough generators. Ive run into folks in the forms that have to speak on all subjects and their view is the only one that counts

 

[CharlesinGA]

Over the years Onan has produced quite a few different variants of the 2500/2800 series generators. The earlier KV series (which is what I have in my trailer) and there are (at least the way Onan breaks down the manual applicability) five different variations of them with a number of sub variants. The later model HG series are distinctly different in dimension, layout and configuration, basically turning around the entire insides, and including an exhaust that can be configured for either bottom or side exhaust, a major improvement over the older KV series which was bottom only. The HG series in non inverter configuration only seems to have one spec letter, and the inverter models have two different spec letters. In all but one circumstance the manuals cover both the 2500 (watt) LP models, and the 2800 (watt) gasoline models.

Link to Onan Manuals page.

The first of the newer HG series seems to have appeared in 2018 judging from the dates on the manuals, and the oldest of the HG inverter models most likely appeared around 2020, based on manual dates, while the older KV series may have appeared about 1992, again judging from the dates on the manuals.

I say all of this to emphasize the range of models and variants of the units. Some overlap from the older design to the newer is inevitable as manufacturers maintained some inventory of these and were installing older designs (to use up stocks) even while newer models appeared. Its a first in, first out supply chain.

These generators have been used in truck campers (probably their main use) while I have seen people mention on forums that they also have them in their 5th wheel, or in in my case, Bigfoot installed them under trailers. They were also used mounted ON TOP of horse trailer/living quarters models (as in this video). The vibration from those must be particularly annoying.

I have included my Youtube video just so you can see what my model looks like. Later HG models are quite different looking.

Charles

 

[Gary RV_Wizard]

There are more than a few examples of a manufacturer de-rating a piece of equipment to comply with some regulation, federal, state or local. The extreme example is Caterpillar "de-rating" their diesel engines for on-road use rather than spend $gazillions to meet new EPA regs for on-road diesels. It simply wasn't worth the necessary investment.

 

[CharlesinGA]

In order to meet the EPA guide lines they drop the breakers down to 20 amps from 30 amps.

I'm having a difficult time believing or understanding this, as 2500 watts is just barely over 20 amps at 120v, and my 3600 watt propane unit in my motorhome had a ?30 amp breaker?, I cannot see Onan putting in too large of a breaker, its there to protect the output wiring and at 30 amp, its not doing its job safely.

EDIT: I just went out and crawled under my trailer and opened up the generator. Its a model KV spec L built in 2007, and the breaker itself has no markings on it, however it has a sticker next to it that says

Circuit Breaker -->
25 amp

The data sticker says 20.8 amps at 120v

Charles

 

[Kirk]

In order to meet the EPA guide lines they drop the breakers down to 20 amps from 30 amps.

If that was the only change, I would think that one could get one of the higher rated circuit breakers that Onan uses in other versions and replace the 20A that is in yours. The catch is that there might have been some other changes in derating it.

 

[KnightEagle]

Since it is now 2025 I can change out the breaker and go with the 30 amp. But what charles was say his had a 25 amp if i read his post right. Before I change it going to do more research have almost 2000 hrs on mine. Saw the size of the 3600 spec's just a little to big in size to fit. Have to check on the 25amp feel it be a safer change than the 30amp.

 

[CharlesinGA]

The units are not designed to put out over 20 amps continuously. You got an A/C running, probably right at 15 amps, the fridge is between 3 and 4 amps, then throw in the microwave and you just overloaded it. The fridge should have been on LP and then you probably can run the MW with the A/C, barely. Don't forget, the converter is running also. Depending on the charge state of the battery and the DC loads (lights, fridge control circuit, a few other things like that, and it can be drawing anywhere from 100 to 400 watts, which is another 1 to 3 amps.

It would be good to see a pic of the data tag for your unit.

There is a new line of RV generators by RVMP that mimic the Onan for size and generally have as much or more power output. They are all inverter models and dual fuel, with much lower price tags. Norwall carries the full line of them an Onan units. $3599 (RVMP) vs $4478 (Onan)

 

[CharlesinGA]

Its not really possible to call one generator "derated" vs the other. Both the older KV models (LP version) and the newer HG models are rated at 2500 watts, or 20.8 amps. Mine at least, and it might be possible to infer that all of the KV models, had a 25 amp breaker to provide some momentary overload capacity (breaker capacity is not listed in the install manual), while the later HG models do have specified, in the specs in the installation manual, a 21 amp breaker. It seems that they were simply limiting overload capabilities of the unit. Remember, both are 2500 watt in LP configuration.

After Los Angelas agin had to see the Cummins near Yuma Az check it and found a letter from Cummins that everyone misted There was a change made in 2016 in that model generator that cut the power output to meet air quility to meet the EPA.

Did the dealer actually show you the letter? did it actually say that due to EPA rules they were limiting the output of the generator? Did this letter specify your model generator?

Simply put, it appears to me, the generator is doing what is is spec'ed and advertised to do.

Charles

 

[Gary RV_Wizard]

If that was the only change, I would think that one could get one of the higher rated circuit breakers that Onan uses in other versions and replace the 20A that is in yours. The catch is that there might have been some other changes in derating it.

Might, but almost surely not. Reducing the breaker size limits the load rather than changing the operation of engine or alternator. It's a preventative rather than a mechanical change.

 

[KnightEagle]

They had kicked it up there chain and there was an email sent back It mention not to change out the breaker for it would open them up to be in violation of the EPA rules on the emissions for it. How it works I'm not sure but once it goes passed 20amps it starts polluting a lot more. And no I didnt get a copy of the email. They did mention if I was running gas in the generator i would have more power. You lose I think its close too 15% from gas to propane.

 

[Kirk]

When a gasoline engine is converted to run on propane, it typically experiences a power loss of around 10-15% due to propane's slightly lower energy density compared to gasoline; meaning it produces slightly less energy per unit volume, resulting in a decrease in engine power output.

 

[CharlesinGA]

Onan units are purpose built for a specific fuel. Thus a 2500 watt LP and the same unit, engineered for gasoline becomes 2800 watt. They are NOT dual fuel.

The RVMP units are dual fuel. Even though designed for permanent installation, I guess the dual fuel aspect does not require many more parts so they are simplifying manufacture and warehousing.

Charles

 

[Domo]

Sorry I didnt meet your god like ideas of a post. It was a direct mention of a fault in the average TC camper generator such as one's found in Eagle Cap, Adventure, Big Foot, etc those that are running on propane not on the pusher's, Hugh diesel rv's and 5th wheels may use larger generators some dont. Not sure if above apply to gas or diesels run generators in rv's

Yes, rude reply to someone that has spent their time trying to learn more about YOUR trouble so they can help better.

As you can imagine - it's easier for someone to give bonafide help when they know the year/make/model of the equipment that is causing the issue.

From what you've supplied as subjective history it seems obvious this is a case of operator overload of the equipment.