PTO generator vs. Stand Alone

[CurlyDave]

I need a generator for two purposes.

1. Powering a 5 hp well pump for up to 30 minutes at a time (~4kW) over the next 12 months, and after the house construction period,

2. Serving as a backup generator for the house we are building. No idea of kW rating, but it should run reefer, freezer, and some lighting, computers, and TV. It will not have to run the well pump, since we will eventually have a storage tank which will work by gravity.

I think the choices I have are PTO generator vs. Stand Alone and then the fuel type. Gas, Propane and Diesel generators are all available. Other equipment we already have uses all three types of fuel, so there is a reason to keep all three types on hand.

My tractor is a JD 110 TLB. Do I have to remove the backhoe to use the PTO? If so, this alone would disqualify the PTO generator.

Anyone have an idea of relative costs, ratings, and expected lifetimes of various types of generators.

Anything else I should know about them?

Thanks.

 

[RFB]

Dave,

I have considered the same question. I have a Kubotoa 5030 with sub-frame BH, and I have to remove the BH to use the PTO.

Even if I did not, I decided against the PTO gen for one principle reason: Household 6

Since my reason for a genset was to provide semi-seamless back-up power, I know that my wife would not take kindly to the setup tasks required of a PTO system. (As a worst case scenario, at 0 dark 30, in a driving rain or heavy snow, and me not at home.)

Propane is derated when compared against gasoline or diesel. Gasoline gensets are not (generally) as durable as diesel.
You can buy home heating oil(HHO) quite a bit cheaper than on-road diesel for a diesel genset. "Power-Sevice" it, and use it in your tractor as well, and you get a pretty freshly cycled supply for both the genset and the tractor.

RFB

 

[CurlyDave]

As a worst case scenario, at 0 dark 30, in a driving rain or heavy snow, and me not at home.

Total agreement there. I have the same thoughts. In fact, even if I am home I don't want to be taking the backhoe off in the middle of the night in the dark.

Gasoline gensets are not (generally) as durable as diesel.

That is an excellent observation. OTOH, how much durability is required? I can reasonably forsee a total maximum of 500 hours the first year, and then maybe 100 hours per year after that.

If the engine lasts 2000 hours, that would be 16 years of service, and in all probability, 100 hours per year of power outages is a gross overestimate. 10-20 hours might be more realistic.

What did you end up buying? Or are you still looking?

Another consideration is how much noise do generators make? I have one in the motorhome which is very quiet, but a replacement costs $5k for 4kW. And, no, it will not quite do the job -- only 120 volts, no 240. It would be really dumb to end up with one that kept me awake all night, even if it did save the freezer contents.

 

[browns40]

Hi curlydave,

We have an 1963 15kW Katolight generator rigged for LP gas at work we use to power some secondary buildings on my "to do" list this summer... needs new starter & some tuning... it has a PTO spline off the engine side so the tractor can power it if major need occurs... loud, air cooled, old technology on the engine... powerhead works fine...

Generators I've been around have always been incredibly loud, but they are 15kW plus... and never insulated for sound...

Typically the engine goes first on a LP or gas (and odds are diesel) powered generator... the engine adds a premium on the price per kW you'll pay for the generator, and requires maintenance regularly like any other engine.

Just the head requires little to none if routinely tested/used. If it's strictly emergency use that is not needed instantly, you can get many more kW for a fraction of the price buying just the head... of course you can always convert your powered to PTO after the motor goes down the road.

But if the cost is not prohibitive & you enjoy annual maintenance, get one with an engine, use it routinely, and it may last beyound your days... like anything, just make sure it's used at least weekly so it doesn't dry out on you when your big jobs are done.

Good luck on the project!

 

[dubba]

Yes, you do have to take the backhoe off to use the PTO. There is a micro switch activated by the frame of the backhoe that prevents you from moving the rock-shaft or using the PTO.

While I only have a small Honda gen for my personal use, I would really like a propane automatic standby generator. I just do not have the need/resources for a large gen set.

Things that I think about propane gen sets

Only have to check the tank occasionally to insure adequate fuel supply. Most gas gen sets to not come with a big enough tank. I don't want to be outside filling the darn thing at 0 dark 30.

Also gasoline motors always seem to have "wet" ignition systems when I want to use them. (just my own bad luck, I'm sure)

I know that propane systems also use ignition systems, but tend not to "flood" like a gas job.

If a diesel gen set is used & a large supply tank is plumbed to it, the tank must be above the level of the gen set, & I worry about the small line gelling up in the cold weather (again, probably just my luck)

Also, I personally have had propane engines apart (from a bread delivery company, panel trucks used in regular deliveries) & the engines were as clean inside as the day they were new.

BTW, the engines were torn down because of head gasket problems due to no maintenance. The owner figured/forgot to replace the antifreeze occasionally & it was acidic, causing head gasket failure.

 

[Highbeam]

Your well is 240 right? Also a 5HP = 3730 watts but a pump motor will have quite a surge to it at startup. Is the 5HP the input requirement or the output rating? If output rating then I would assume an efficiency loss in there too. The pump is your biggest load and I really think a 4000 watt generator isn't enough. I would be looking at the 6000 continuous area.

For 500$ I bought a gasoline coleman contractor style generator with 5500 continuous/6850 peak rating. I have put probably 100 hours on it in the last couple of years. This winter we had a three day power outage it was 18 degrees and we had a windstorm. I got home after dark on the first day and the house with my baby girls in it was down to 60 degrees. No problemo, I'll pull out the genny. Well I couldn't start it and quickly grew tired of pulling the rope to spin the 11HP engine with cold 15-50 oil. I pulled the plug, it had a spark and was wet with fuel. I held my finger over the hole and pulled the rope, good compression. All of this took about an hour and was done with an LED headlamp in the howling wind and cold. I resolved to take the carb bowl off and dump it. There must have been water or bad gas in the bowl since it started right up after reassembly. My point is that a gas engine works very well, consumes about 3/4 gallon per hour, and is cheap but it must be used. I have been told that 90% of generator problems are from lack of use.

I now run it once a month with an electrical load.

Another benefit of the cheap, loud, gas generators is that they are mobile. I roll mine into the piuckup and use it to run my welder. Try moving a water cooled diesel genny.

500$

 

[EddieWalker]

I'll pretty much second everything Highbeam said. Heck, I think I even have the same generator!!!

One thing I'd add is to avoid the Tekumush engine,or whatever it's called. Mine is a Briggs, which is ok. Honda is probably better, but as long as it's not mush, you'll be fine.

I like mine for the protable aspect of it. I can move it anyplace I need it and even leave it there over a period of time and do other things.

The PTO generator severly limits what you can do when your running it.

One particular bad storm that we had came out of nowhere. Steph had parked her car on the dirt close to where we were working. It rained so hard that she was totally stuck almost instantly. I pulled her out with the tractor.

When Hurricane Rita hit, the carpet guys were here and for some reason they drove off my gravel drive and got stuck. Again, I was able to pull them out with my tractor.

I'm not saying you will have people getting stuck all the time like I do, but having the ability to use your tractor and your generator seperatley if you need to might be a very nice advantage.

As for noise, why not run a pipe that goes outside and put a car muffler on it? Or you can store it under an exterior lean to like I do so the sound is very minimal. I also keep five gallos of fuel close by that I use on other things. This way it's always fresh gasoline in case i really need it.

Eddie

 

[3RRL]

Dave,
Personally, I would not use a PTO driven generator for what you want. There are just too many other things to do with the tractor, and your backhoe problem is another. Home Depot sells a lot of stand alone back-up generators, one I'm looking at for my solar back-up sysytem. However, I would also agree with everything Highbeam said. I think you'll need at least 5k to run the pump. I had a smaller Coleman 3500w but no 240v on it so I bought a Generac Wheelhouse 5550 continuous with 8550 surge. It has been great and very quiet....more so than the Coleman even. I use it to run the well pump and do all my arcwelding at the property. It's got lots of power and is portable.

Here's a link to one, but you can get them at Home Depot too. Gnerac Wheelhouse 5550

 

[George2615]

I pondered that question about a year ago. I had an old Sears AC buzz box welder on its last legs, and a 5KW 6250 surge generator that wouldn't quite run my whole house including with the A/C on. I thought of buying separately a PTO generator and a new welder but did not.
My reasons being:
1) Didn't want to tie up tractor just to run a generator.
2) Didn't want to have to remove whatever implement was on the tractor PTO to hook up a generator.
3) Needed a new welder and wanted an AC/DC welder instead of just AC.
4) Needed a generator capable of running the whole house with the A/C on for those 85-90 deg. days when our power seems to go out the most often.

I sold my 5 KW gen. to my neighbor so he could run his house for $300 and wired him up to use it. (He didn't care about having the A/C on) and I bought a Miller Bobcat 250 NT AC/DC welder / 10KW generator with 19 hrs. on it that was factory reconditioned and came with one year warranty.
I left it on the shipping crate and mounted 8" wheels on for portability. Now I can load it onto my truck or trailer with my loader and take it to whatever job I need to do. and have backup power to run the house when needed.

Counting what I got from the neighbor and the price I paid for the recond. unit. it was cheaper than buying them separately.

Just my 2 cents.

 

[CurlyDave]

Your well is 240 right?

Actually, the well is 720' right this minute and still drilling.

Evidently I picked a poor location.

The driller, who also supplies pumps, claims that a 5 hp pump will work down to about 1100 feet.

We have 6 gpm right now, and will stop at either 900 feet or 10 gpm. Somehow I have a suspicion that 900 feet will come first.

 

[jmc]

The electician who will wire your house knows about this, right?

 

[JoeF]

Curley

Having just lived through the destruction of Katrina, we learned a lot about generators. I would vote for the LP gas fired. No worry about bad gas or deisel. You don't have to fire it up once a month with a load. The fuel never goes bad. I just contacted my gas company and they are getting quotes together for me with tank. Just my .02 cents worth.

 

[RalphVa]

We bought a Suzuki (Acrtic Cat) electric start 4400 watt generator right after the Isabel hurricane hit here. Wife paid $2,000 for it then. That was in line with Honda-powered units I priced at one time just before that. You don't want a pull-start unit unless it's really easy to start. A friend's that I borrowed once did pull start easily. I had one once in Baton Rouge that was almost impossible to start and to run smoothly without a full load on it. So, get a good one and expect to pay for it.

The Suzuki uses 0.5 gallon/hr and will run for about 8 hours. It's a pain keeping cans of gas around to refill it. A diesel on a tank or a propane-powered unit would be less of a nuisance along those lines. Also, both a diesel and a propane-powered unit would likely be instant start. The Suzuki, like all gasoline engines that sit for a month or so between uses, doesn't start instantly.

The Suzuki powers our family room, master bedroom and bath, kitchen lights & microwave, garage, carriage house freezer, frig down here and computers. The well pump requires shutting everything else off to start it up but lasts with pressure tank pressure quite a while. After Isabel, my wife and I were able to get hot showers with the Suzuki powering a Tiny Titan 2.5 gallon hot water heater I use for my outdoor shower in addtion to the above-named duties. The TT is only 1300 watt.

I've thought about getting a little bigger PTO-driven unit, but I screwed up in building the carriage house where the tractor is parked by not putting a "people" door on the main level. Need power to open the carriage house overhead doors. Can't get tractor out if no power!

I run the Suzuki about 15 minutes or so once a month to around 40 days between runs to keep its battery charged, etc.

Ralph

 

[CurlyDave]

Well, as usual, the plot thickens.

The well is 780 feet deep and is going to have a 5 HP pump. The well driller says he will call me & tell me if I can power this from an 8kW generator, or if I need a 10kW. So, this certainly sets some requirements.

An electric starter is a must for this old guy (me, not the generator).

I am wondering about this little puppy from Loew's
12.5 KW Generac generator .

While it is a lot more $ than the 4kW ones, the 4kW ones won't run the well pump and this one will for sure. I suspect that this one will run the entire house in a power failure. It is about 450 lb dry, maybe 600 with a full tank. This has disadvantagves and advantages.

No matter what, any "portable" generator is going to ride in the back of the pickup to go very far. I can't lift a 250 lb generator into the truck by myself any easier than I can lift a 600 lb generator. But, the backhoe can pick this one up by a chain through its lifting point and load it easily. The small ones don't have a factory-installed lifting point.

And, the builder has had smaller generators walk away from construction sites. Somehow I think this one is going to stay put more easily at 600 lbs. I will probably chain it to something really heavy as added insurance.

Fuel. As far as this goes, as much as I would like diesel or even propane, the cost of a gas generator is less than other fuels. Back when gas was $1 per gallon, $10 for a quart of Stabil to keep the gas fresh for a year seemed like a lot. Now that gas is $3+ per gallon, the Stabil seems cheap. I have had very good luck using this in small gas engines. The cost advantage of gas is very good.

For jmc: The electician who will wire your house knows about this, right?

Actually he doesn't. Not because I want to keep it a secret, but because we haven't chosen an electrician yet. The general contractor knows.

This seems like a lot more generator for the money than the Artic Cat...

 

[Joe1]

I'll admit I know little about electricity, but is the power output "clean" so that electronic things run properly? That also seems like a lot of fuel to burn and to resupply; nearly 2 gallons per hour or 15 - 20 gallons per day if running full time with a large load. You could be hauling 100 - 125+ gallons per week. If you kept that up for long, a diesel generator with probably half the fuel consumption would pay for itself in convenience and savings in fuel used to bring the fuel home. Off road diesel is probably cheaper than regular gasoline in your area like it is in mine and it's safer to handle and store.

The 25 hp Yanmar in my John Deere burns about 1/2 - 3/4 gallons per hour at full throttle. That's less than 1/2 of the generac gas engine.

I just reread your post and I over estimated the use for the generator. Will you use it for construction on the site or just as a back up. As far as for emergency use, you can cycle your appliances so they don't all run at the same time, i.e. 6 hrs on the freezer then 6 hrs on the fridge. You could keep that up for a few days on a smaller generator and still use other appliances in between fridge and freezer runs. Do you anticipate a lot of power failures. No hurricanes or tornados where you live.

 

[Highbeam]

It surely is a bummer to have to buy a single generator for such a split load. When running the pump, you need 10,000+ watts, the rest of the time a 4000 watt Onan would do the job and burn much less fuel. You don't mention a need to run AC in the new home but if you want to the 10KW generator can do it so long as the pump stays off. That's a huge demand for your pump, a typical household service is 200 (110 volt) amps and that pump will suck 100 of them. You'll notice it when that puppy fires up.

I kind of think that the well guy might be off on his pump sizing or at least the power needs. Cripes, the Lincoln website says my welder needs a 15000 watt generator but my little coleman 5500 runs it just fine.

 

[Soundguy]

I see lots of people are really down on pto generators due to the 'what if' factor... What if I need to use my tractor for 5 minutes to pull the neighbor out? What if.. what if.. If you do.. just unhook that little shaft from the back of the tractor and then go pull the neighbor out.. then drive back and hook that little shaft back up...

Being a florida resident.. I've been thru bad storms.. most notably the last couple years. I can certainly tell you.. no one around me ran a generator continously.. they would start them up to do certain tasks.. perhaps pump up some water.. or power up a fridge/freezer for an hour to keep it cold... I don't know of anyone who ran them continously. Seems like that 'level' of use is compatible with a pto gen... use the tractor to do clean up.. or pull the wife's car or the workmans truck out.. then go back to power generation.

And for best case? just have 2 tractors /forums/images/graemlins/wink.gif

A backhoe mount might make me rething a pto gen though..

Soundguy

 

[EastTexFrank]

I use a 3800 watt/5200 surge no bells or whistles gas generator just to run the fridges and freezers when the power goes out which isn't all that often. The longest outage we ever had was 40 hours. The issue for me is keeping enough fresh fuel around to keep it running if we ever had an extended power cut as I don't use a lot of gas. I think if I ever had to do it again I would get a bigger generator with a tri-fuel kit so it can use gasoline, natural gas or propane. We have natural gas at the house so there would be no fuel storage problem and I could still keep the gasoline to use it away from the house. I actually costed out such a system with a transfer panel and it wasn't too bad but I couldn't really justify it because our outages are so few and so short (so far). I think Bob Skurka installed such a system at his place and was very happy with it.

 

[bugstruck]

Dave,

Couldn't agree more. Many young guys can't grab and load a 250 lb. generator solo. I'm not and I can't. I saw that your going with a 3HP pump in the other thread. That will take about a 10KW generator and be somewhere around 6-8 KW real demand, I think. Here's a link to Goulds submersibles Pump manual . May be of some interest. Somewhere down the manual it references the generator KW requirements by pump HP. Got to looking at their wire size requirements too. Pretty stout for a 3HP at your distances.

Looks like that 12KW unit might be the ticket, so you don't have to shut much load when pumping water. Assuming gasoline, fuel consumption would stop me from anything larger and may make me think diesel if you can keep the generator reasonably warm. Need that fuel around too. For added assurance when I turn the well pump on, I shunt load on my 5KW with a freezer, fridge, oil burner, and lights (AC, stove, and oven are always off), but I know it holds even when I've forgotten to back the fridge out /forums/images/graemlins/tongue.gif. Actually, that 5KW runs my entire house less the few high demand devices. However, I'm only pulling 1,380 running watts on the well pump.

I'm not big on the permanent residential generator installations. Surely, some have had good service over time with that type of installation, but my experience is they are one level above junk. Commercial grade generators aren't trouble free and they have decent quality controls. They still require routine maintenance and exercise to keep them in good working order. Some commented propane or natural and that makes me think permanant in most applications. Most of the problems I've seen on permanent residential units wasn't fuel related, but controls or accessories, and sometimes shear negligence. So the step up from portables isn't always the reliability increase some expect. Main advantage being capacity and convenience.

Portables do have a way of earning their service demands though. Generators are easy to forget, but one need do it only once........ which reminds me /forums/images/graemlins/wink.gif

Most importantly, I saw the well may be in the 6.5+ GPM range. That is rather good news.

 

[Cord]

Natural gas gives you a virtually unlimited of fresh fuel, however because natural gas has fewer btu's per unit, the engine will need to be larger. The same is true for LP, except your fuel is limited to the tanks capacity. Gas generators are the cheapest, but the fuel is volitile and must be mainatined. Diesel generators are generally a better quality unit and their fuel is exceptionally stable. 10 year old diesel is just as fresh as new diesel. One other item for you to consider is how often the generator will be used. The generator needs to be run every 6 months or so or it will loose it's magnatism. Once the magnatism is lost it can only be restored through a simple proceedure involving another generator or line voltage. Two things you might not have in a power outage.