Hey Guys - I thought it would be an interesting topic to discuss Onan’s newer style “Inverter Based Generators” which use a processor controlled variable speed protocol to vary the generators rpm to match immediate load demands. In any case, inverter based Onan generators are quieter, more fuel efficient and will last 2-3 times longer than a standard Onan thanks to the fact they spend most of their time operating 50% slower than past Onan generators.
Fortunately my new Renegade Verona - Was equipped with a 8 kw “Inverter Based” gen-set. As soon as you start the generator, you'll note it's a departure from the older Onan generators which were required to operate at high rpm's even when there was no loads placed on the generator.
Presently all the newer 6 kw & 8 kw Onan diesel generators - Are "Inverter Based Generators". Onan just released their first gas / propane inverter versions called 2500i - 2800i for B & B+ Vans. Last time I checked, the 10 /12 kw Onan’s were still using the older constant speed protocol. The primary difference of the older Onan generators is they were required to run at a set speed around 1800 rpm. This was mandatory for the generator to maintain a true 60 cycle wave form. Any deviation in speed, would cause the sine wave frequency to change.
The term Inverter Based Generator - Can be a bit confusing to some RV owners. While this technology is new to Onan's RV units, inverter generators have been around for decades. In fact, my 15 year old Honda 1000 portable generator has this inverter technology. When you start a inverter generator it will run at a high idle speed for a few minutes to reach operating temperature. Once this is accomplished, the generator then slows back down to idle speed just as your main engine would waiting for a load.
These newer inverter generators - Operate differently as they now dump the alternators output into a built in inverter module which maintains the generators output at a constant 60 Hz, regardless of rpm. As soon as a load is applied, the inverters processor samples the required amperage, then quickly increases engine speed to a level to maintain that load. It’s this process of allowing the engine run slower which conserves up to 40-50% fuel compared to the older generators which were required to run at nearly 50% throttle constantly.
On a few Occasions - When I wanted to top off my Renegade’s lithium batteries set, I'll use the generator to power my Xantrex 3012 inverter to charge the batteries at 150 amps, or at 300 amps using my second onboard Xantrex Pro 3000 inverter charger. The beauty of this new generator is runs just a bit over idle speed to accommodate this charge cycle. In fact, you hardly know the generator is working. This same process with my older Onan generators was awful, since the generator would have to run at high speeds even though it had a very minimum load. This low speed charge cycle only consumes around .10 gal hr. verses half a gallon an hour on the older generator units. You'll also note that when running the roof AC unit, as the compressor cycles off, the generator lowers to idle again conserving fuel and reducing noise.
In my discussions with a number of RV owners - I was surprised to find out that many owners did not realize their RV’s were equipped with this new technology generator. If you’re not sure you have an inverter generator- Just start the generator with no loads applied. If the generator stays at idle with no load, then you have the new inverter set. If it runs at a constant fast speed with no load, you have the older ten-set.
While on the topic of Inverters - Most Renegade’s from 2020 now use an inverted based compressor motor for the refrigerator as well. This system requires half the power of past units. The refrigerator in my Renegade only draws 3 amps, where the same 18 cu ft refrigerator in my Newmar drew 6.5 amps to operate. The inverter controlled compressors have the ability to run at seven different speeds for efficiency drawing as little as only 1 amp to maintain temperature.
Since my coach runs entirely - On it's own 16,080 watt hour Lithium battery which runs the A/C, my generator is seldom used. My coach is a little over a year old now, and I’ve only run the generator 3.1 hours for testing and exercise. Regretfully some type B and B+ & C manufactures are now removing the generator when they install a lithium package, this is not a good practice. I would not own an RV without a generator.
I did want to mention in the article they also offer a a unique advantage for RV lithium battery charging, since you can charge your lithium batteries with the gen at idle, preventing the use the engine with all its DPF extended idling problems.
In conclusion - I could not be more pleased with its quiet running and economical fuel operation. Congrats to the folk's at Onan for this major improvement in RV generators.
Stay Safe Guys - Mike
Thanks for the replies - Regretfully instead of this thread being friendly and educational so we can all learn from each other to further enjoy our RV’s, a few users have instead chosen two attack it and my credentials. For those who think I just dreamed up this topic, as a hobby, I spend 8+ hours a day designing lithium systems for their integration to RV’s. I designed the very first lithium system for RV’s in the late 90’s. Since then, I have provided consulting information to numerous RV manufactures, as well as industry leaders such as Lithionics Battery, Xantrex Corp, E-Gen and others. In Fact, I’m presently designing the first 100 volt lithium battery system for my Renegade. This system will provide up to a week of “off the grid time”with the roof A/C running. Other unique features include; the RV’s cab A/C compressor is converted to electric and powered by the coaches same lithium system allowing the dash air to run even with the engine off. This is big news for RV’s since the cabs AC unit outputs 19k btu.
In fact, I just returned from a trip to Elkhart and Decatur visiting with technicians of 12 different RV manufactures for a “Show & Tell” of my Renegades latest lithium design where the entire coach and appliances are powered solely from lithium allowing the roof AC to run for two days or longer. While I’m presently documenting this newer system for an upcoming video, for those interested in a more conventional lithium system for their RV, I have included some links below of a few systems I designed. You might have to copy and paste the links!
Stay Safe - Mike
In fact, I just returned from a trip to Elkhart and Decatur visiting with technicians of 12 different RV manufactures for a “Show & Tell” of my Renegades latest lithium design where the entire coach and appliances are powered solely from lithium allowing the roof AC to run for two days or longer. While I’m presently documenting this newer system for an upcoming video, for those interested in a more conventional lithium system for their RV, I have included some links below of a few systems I designed. You might have to copy and paste the links!
Stay Safe - Mike
Thanks for all the replies - I recently sold my 2019 Newmar New Aire which had an 8 kw genny to purchase my newer 2020 Renegade Verona with an 8 kw Onan as well. Upon delivery, I immediately noticed a contrast difference in the generators quieter operation and lower idle speed which compelled me to contact Onan to investigate the difference.
Yesterday I finally managed to have a short conversation with my busy friend Bill Stubbs, Bill is possibly one of the most knowledgeable guys on the planet with Cummins, Allison transmissions as well as Onan.generators. Bill is the one who uncovered the poor engine performance in RV’s which was caused by a protocol called “Fuel Sense” which was bogging down Cummins engines in RV’s. Fuel sense caused over-shifting in an effort to save fuel.
Bill mentioned that while all Onan diesel generators use an inverter module, the newer Onan’s now use a different inverter based processor protocol, which allows the Onan to idle slower, as well as control lower operating speeds to make the somewhat noisy Kubota’s engines a bit quieter and more fuel efficient. He mentioned these new diesel protocol’s were inline with the new 2500i and 2800i inverted based smaller gas generators recently released.
I would additionally like to personally thank the moderators for re-opening the thread!
Yesterday I finally managed to have a short conversation with my busy friend Bill Stubbs, Bill is possibly one of the most knowledgeable guys on the planet with Cummins, Allison transmissions as well as Onan.generators. Bill is the one who uncovered the poor engine performance in RV’s which was caused by a protocol called “Fuel Sense” which was bogging down Cummins engines in RV’s. Fuel sense caused over-shifting in an effort to save fuel.
Bill mentioned that while all Onan diesel generators use an inverter module, the newer Onan’s now use a different inverter based processor protocol, which allows the Onan to idle slower, as well as control lower operating speeds to make the somewhat noisy Kubota’s engines a bit quieter and more fuel efficient. He mentioned these new diesel protocol’s were inline with the new 2500i and 2800i inverted based smaller gas generators recently released.
I would additionally like to personally thank the moderators for re-opening the thread!
