Propane generator recommendations?

[Troubleshooter]

Looking to purchase a propane generator as standby to run selected circuits in the shop and the house during a prolonged power outage or natural disaster. Plz note that I am only considering propane generators for this particular application. Currently, I'm considering Generac or Kohler, probably in the 17-20Kw range. Looking at online reviews, there is a fair amount of both positive and negative feedback on the Generacs, but very little feedback on the Kohlers. Therefore I'm counting on the collective wisdom and experience of this group regarding good or bad experiences with either brand.



Thanks in advance for any experience that you can share to help in this decision!

 

[Bill Stockard]

Looking to purchase a propane generator as standby to run selected circuits in the shop and the house during a prolonged power outage or natural disaster. Plz note that I am only considering propane generators for this particular application. Currently, I'm considering Generac or Kohler, probably in the 17-20Kw range. Looking at online reviews, there is a fair amount of both positive and negative feedback on the Generacs, but very little feedback on the Kohlers. Therefore I'm counting on the collective wisdom and experience of this group regarding good or bad experiences with either brand.



Thanks in advance for any experience that you can share to help in this decision!

You are probably looking at generators powered by air cooled engines. In that case, I would prefer a Kohler engine over a Generac. Cummins Onan also makes a generator in that range. I don't know where Cummins Onan presently manufacturers their air cooled engines.





I too am considering a 30kw home standby liquid cooled propane generator. My choices so far are first Cummins Onan and then Kohler. What I like best about the Cummins Onan besides the Cummins Onan quality and reliability is that it uses a GM 3. 0L four cylinder engine (no timing belt) running at 1800 RPM. Generac, even though less expensive, is not one of my choices. I've had two Generac RV generators, and from that experience, I don't want another one.



Bill

 

[BIGNASTY]

My standby

I have a propane stand by GEN WATER COOLED





Kohler 13 ERG 1800 RPM water cooled propane generator. Suitable for off grid or backup power. $9120... spec sheet Kohler 13 ERG



http://www.hardydiesel.com/propane-generators.html





May not be as big as you need but mine is just to charge my batteries and I can run lights and power for home and some of my shop with it when not doing battery duty.

 

[JJPage]

Having maintained standby power systems for a major telecommunications giant, which had a large variety of units, I am totally partial to Onan. Their reliability exceeded all the others.



Stay away from the Olympians that Caterpillar sells, they became a major maintenance nightmare right out of the gate, then once warranty was expired they were my problem.



Kohler had some small units which were mated to an air cooled Deutz diesel which were good units, and I also had a couple of Kohler gens powered by 3412 (V12) Cats. Kohler would be my 2nd choice.



I know you want propane powered, here's a link to some Onan units.

Cummins Onan

 

[Bill Stockard]

Having maintained standby power systems for a major telecommunications giant, which had a large variety of units, I am totally partial to Onan. Their reliability exceeded all the others.

I've been researching generators for about four months and your evaluation is what I'm finding. I don't want to make an expensive mistake. There's a reason why some ar less expensive than others.



Bill

 

[Troubleshooter]

Thanks for the replies thus far; keep the insights coming!



You know, I have a small Onan gasoline genset and it never occured to me that they might have a standby-sized propane unit. I'll have to look into those. The Model 20A looks like it might fill the bill.

 

[CBari]

Don't know if it is an option for you but what I ended up doing was getting a pto 25k generator. I hook it to my tractor and let it run. I always have farm fuel around and even though diesel is higher than propane, I don't have to have an extra fuel source for me.

 

[Bill Stockard]

Don't know if it is an option for you but what I ended up doing was getting a pto 25k generator. I hook it to my tractor and let it run. I always have farm fuel around and even though diesel is higher than propane, I don't have to have an extra fuel source for me.

Be careful what electrical loads that you connect when using a tractor PTO driven generator. Many tractor driven generators don't have close voltage regulation and/or low harmonic distortion which could damage sensitive electronics and digital controllers.



Bill

 

[Troubleshooter]

Don't know if it is an option for you but what I ended up doing was getting a pto 25k generator. I hook it to my tractor and let it run. I always have farm fuel around and even though diesel is higher than propane, I don't have to have an extra fuel source for me.

Thanks, but not an option for me. First, it would require too much setup time (not instantaneous like a backup generator), second it would tie up the tractor. Looked at a few PTOs at farm auctions, and the used ones were bringing as much as a new gas or diesel generator.

 

[Troubleshooter]

Well, here are the two models that I'm considering based on input. One is liquid-cooled and the other is air-cooled with the "smart switching" module. Any reason why one should be better than the other for my purposes?



RS-20A air cooled:

Cummins Onan



RS-20 liquid cooled:

Cummins Onan

 

[NIsaacs]

Personally, I would prefer the liquid cooled model. Four cylinder power at 1800 RPM v/s two cylinder air cooled power at 3600 RPM. The 4 is twice as heavy and does use more propane, 2. 2 gal. per hr at 1/2 load v/s 1. 5 gal.



I am sure it is way more $$ tho. I think you will be happy with either/or They both look like an awesome unit.



Nick

 

[Bill Stockard]

Well, here are the two models that I'm considering based on input. One is liquid-cooled and the other is air-cooled with the "smart switching" module. Any reason why one should be better than the other for my purposes?



RS-20A air cooled:

Cummins Onan



RS-20 liquid cooled:

Cummins Onan

If you are going to use the generator intermittently as standby power and only need 240-volts and single phase. I would go with the air cooled generator. It will use less fuel, lower initial cost, less weight, smaller footprint, and no cooling system to maintain. If you need 3-phase power, you will have to go with the liquid cooled. For generating power long term, as being off the grid for weeks or months, I would buy the liquid cooled Onan.



Bill

 

[BimmerAgent]

Generac

I just installed a Generac Natural gas air cooled standby unit with a load-shedding switch. It's 15kw, which is plenty for me, especially since, with the LS switch, you can prioritize which circuits shut down should the load become too much for the genset. The switch allowed a smaller genset, since it would be a rare instance indeed if we needed to run all the high power consumption appliances and pumps at the same time. I'm sure you could find one in propane. It's a very nice, sturdy unit, and pretty quiet too. Bruce

 

[rscurtis]

I would lean toward an 1800 RPM unit despite the additional cost. A 30 HP engine running at 3600 RPM on 2. 5 quarts of oil is not a recipe for longevity. Also, Onan does not say who's engine they're using. True, you won't use it a lot, but it's most likely to suffer a failure just when you really need it. Too bad you're stuck on propane, there are some nice diesel options available, both new and used. I have this 7KW unit for my house, it was the smallest diesel set they made at the time.

 

[Troubleshooter]

If you are going to use the generator intermittently as standby power and only need 240-volts and single phase. I would go with the air cooled generator. It will use less fuel, lower initial cost, less weight, smaller footprint, and no cooling system to maintain. If you need 3-phase power, you will have to go with the liquid cooled. For generating power long term, as being off the grid for weeks or months, I would buy the liquid cooled Onan.



Bill

Thanks, single phase will fulfill my requirements.



As for long-term vs. short term, the intent would be short duration runs over varying lengths of time. Most of the power outages here last a few hours but occasionally a big storm will come through and knock out the power for days. When the hurricane came through a few years back, my kid brother was without power for about a week. A friend in a nearby town was without power for three weeks. A storm which takes out power lines or a transformer could have me down for weeks also.



My intent would be to run for a couple hours at a time a few times a day in order to keep foodstuffs cold/frozen, run heat or A/C for the minimum necessary periods, etc. Even if the power was out for an extended period, I think that I could get by with disciplined use of the genset.



Now if the zombies come out to play, all bets are off!

 

[Bill Stockard]

I would lean toward an 1800 RPM unit despite the additional cost. A 30 HP engine running at 3600 RPM on 2. 5 quarts of oil is not a recipe for longevity. Also, Onan does not say who's engine they're using. True, you won't use it a lot, but it's most likely to suffer a failure just when you really need it. Too bad you're stuck on propane, there are some nice diesel options available, both new and used. I have this 7KW unit for my house, it was the smallest diesel set they made at the time.

The liquid cooled version is double the cost of air cooled. The 3600 RPM air cooled Onan generator uses an Onan V-twin Onan engine equipped with an engine oil cooler. The generator uses propane vapor which is a "dry" fuel and there's less contamination of the engine oil than with liquid fuels. Propane fuel is stored in a pressurized container, isn't exposed to the atmosphere, and is much less affected by long term storage than gasoline and/or diesel fuel.



Bill

 

[oilburner]

I am a former Onan/Cummins tech and am partial to Onan/Cummins products. I serviced all makes but by far the best were Onan/cummins units. Generacs I found were prone to failure. Kohlers are OK but not as relaible as Onan. The 13 Kw 3600 Rpm Onan uses a very dependable Robin Subaru engine as said earlier with an oil cooler. The 20 Kw air cooled 3600 Rpm Onan uses a Briggs also with an oil cooler. For the occasional outages they are excellent choices. For extended outage Liquid cooled 1800 Rpm is the way to go. The Onans are more expensive but quality is never cheap. They are also equipped with isochronous digital governors for excellent power quality, which is very important. Also most critical infrastructure projects I have seen use Onan/Cummins for good reason. I have seen 30 to 50 year old Onans running perfectly.

 

[Bill Stockard]

I am a former Onan/Cummins tech and am partial to Onan/Cummins products. I serviced all makes but by far the best were Onan/cummins units. Generacs I found were prone to failure. Kohlers are OK but not as relaible as Onan. The 13 Kw 3600 Rpm Onan uses a very dependable Robin Subaru engine as said earlier with an oil cooler. The 20 Kw air cooled 3600 Rpm Onan uses a Briggs also with an oil cooler. For the occasional outages they are excellent choices. For extended outage Liquid cooled 1800 Rpm is the way to go. The Onans are more expensive but quality is never cheap. They are also equipped with isochronous digital governors for excellent power quality, which is very important. Also most critical infrastructure projects I have seen use Onan/Cummins for good reason. I have seen 30 to 50 year old Onans running perfectly.

When did Cummins-Onan quit using Onan engines? According to their current specification sheets on their web site, the 20kw air cooled Cummins-Onan generator is powered by a V-twin Onan engine. However, i have heard a rumor about Onan not building engines in the US anymore and that was the reason I questioned where the Onan engines were manufactured in my first post.



Your summary of Cummins-Onan quality and dependability agrees with the research I have done on home standby generators. I agree with your recommendations for air cooled vs. liquid cooled standby generators.



Bill

 

[rscurtis]

"I have seen 30-50 year old Onan's running perfectly". Do you mean like these? I bought the 4 cylinder unit at auction in 2010. After a little electrical work, it runs perfectly. It would probably cost Onan about 10K to make that generator today.

 

[oilburner]

Linamar in Guelph Ontario used to make the Onan engines but from what I understand they got too costly.