Comparison What's best for standby power?

[rmorey]

Hey Rod,

Everyone has an opinion. (including me) If it was me, I would calculate the load "needed" to run during the outage. Freezer, fridge, some lites, sump pump, etc. Add 'em up and add a contingency, say 15% more. Now you know how big a genny you "need". Check specs on all types of that size to see which will be the most efficient to operate. You may find that another portable will cover all the required loads. I think that, as others have said, the pto model will use whatever the tractor burns, and the propane version will cost the most to buy.

I bought an 8kW/12kW Generac w/electric start from TSC in Smiths Falls last year for $1,500. Burns about 30 litres in 12 hr run time. The propane was a little cheaper to run but cost more than twice as much to buy.

 

[jenkinsph]

If you have elderly with handicaps the need for constant power becomes more real. I would recommend the Kubota 7510 with a 10kw pto genset and add an additional fuel tank with about 25 to 50 gallons of treated diesel fuel. I would venture that you can make a simple fuel hookup by adding a new fuel cap that will extend the vent to the additional tank. I use this fuel setup for my small Honda gensets it works well and greatly extends your run time.

A fuel tank and a pto generator would be a simple and cheap fix imo. Good for those members with several tractors not for one tractor households.

 

[newbury]

Here's an older CCL ad I just ran across - use it for comparison of what one may get -

ONAN PTO GENERATOR. 30 KW UNIT. HAVE OPERATORS MANUEL AND PARTS LIST. $1500.00 SHAFT NOT INCLUDED. CALL 662-534-7428 OR 662-538-3523 FOR MORE INFORMATION.

 

[tcartwri]

During the Ice Storm in 98 we had a propane cast iron stove that had a piezoelectric thermostat and igniter. Kept the house tolerable. No maintenance required and you can enjoy it when you want.

Water supply is obviously another matter, and lack of water can make life miserable. We were without power for two weeks. Showered at work, and flushed the toilets with melt water on the stove.

DC powered sump pumps are available and will last for quite a while on a deep cycle battery.

 

[Rod in Forfar]

The generator project (needs assessment phase) nears completion:

We're leaning toward a fixed, pto driven unit, located in a garage, bolted to the floor or to a stand, accessed by pto shaft, permanently wired into the house system.

Reasons for this choice are largely based upon what I've read in manuals and comments on this site.

1. Trailers for new pto generators are expensive, and cheap ones tend to twist under load.
2. 3 pt hitch frames for generators cost the earth, pose similar problems to trailers, and have short, tricky drive shafts which might not fit all of my tractors.
3. PTO shafts must be straight to provide uninterrupted 60 cycle power, as any jink in a universal shaft will put a blip in the current frequency.
4. PTO generators are reputed to be maintenance-free for long periods if stored out of the weather.
5. A diesel tractor sitting beside a box stove is more likely to start in sub zero weather than a propane generator engine.
6. Yesterday in Smiths Falls I looked at a relatively new Generac cabinet unit sitting at the back of the TSC store (returned because of a missing part). The cabinet was already rusting. I have no information to suggest that these units are durable in the long term, and a bit to suggest the contrary.
7. Automatic operation isn't all that crucial when we're on the property virtually all of the time, and I usually find an excuse to exercise one or two tractors each day.
8. A major part of the Generac package is the panel and cable, neither of which would be of much use to me without major drilling through a stone wall (60"), but there's already a 30 amp generator panel in place and 30 amp-capable cable to support it, so a small pto unit could just plug in.
9. Diesel is easier than propane to steal from a furnace tank in case of shortage due to extended power outage -- I even have a 12v pump for the purpose.

Remaining questions:

Given that my cable through several feet of concrete into the house has a maximum capacity of 30 amps, the capacity also of the generator panel, what will a 21 hp tractor (with 17 pto hp) do on a 15 kw generator?

Is there a compelling reason to choose a generator larger than 7.2 kw?

Thanks for the insights and advice. If you see wrong assumptions in points 1 through 9 above, please point them out.

Rod

 

[arlen4720]

Sounds like pretty solid logic to me. I never thought of a permanent mounted PTO unit, but it sure would keep the cost down. You seem to know what you need for a size, so the the only reason I can think of to go with a bigger generator is because bigger ones may be easier to find. If you do get a bigger one, just make sure you fuse or otherwise protect the 30 amp feeder going to your panel.

 

[rmorey]

Rod, as arlen4720 has said, your logic makes sense. The only thing I would suggest is the larger one is more popular, therefore more likely to be cheaper. In addition, a larger unit will operate at a lower percentage of maximum than a smaller one.

If you draw 30 amps, your 7.2kW genny will provide it, but also it will run at near 100% capacity. If you had a 15kW genny and draw 30 amps, it will operate at a closer to 50% capacity and less likely to fluctuate power specs.

 

[Rod in Forfar]

Rod, as arlen4720 has said, your logic makes sense. The only thing I would suggest is the larger one is more popular, therefore more likely to be cheaper. In addition, a larger unit will operate at a lower percentage of maximum than a smaller one.

If you draw 30 amps, your 7.2kW genny will provide it, but also it will run at near 100% capacity. If you had a 15kW genny and draw 30 amps, it will operate at a closer to 50% capacity and less likely to fluctuate power specs.

You're right about the prices on 7.2 KW Baumalights. A dealer in Kingston today quoted me $4K for one, generously knocking off $450 if I deleted the trailer.

Tomorrow I'm driving 3 1/2 hours to Brampton to look at a used model since the vendor came down to $2100 CDN. He's a John Deere dealer who sold the unit to his FIL, and now is disposing of it as part of the estate. He assured me that Baumalight is assembled by the Mennonites around Listowel, Ontario, out of Japanese components. I have two other Mennonite-built implements, a block splitter and a snow blower, and they've given excellent service. So though I spent half the afternoon on the Northern Tools website looking at their clone of this model priced at $899 US without pto shaft ($325) and trailer ($669), I'll likely go with the Canadian model with the solid reputation and tow it around behind the Kubota on its trailer. The dealer/vendor, btw, assured me that neither the 7 kw generator nor the attached 21 hp tractor will generate enough torque to twist around much when load is applied.

 

[newbury]

<snip> Northern Tools website looking at their clone of this model priced at $899 US without pto shaft ($325) and trailer (didn't look), I'll likely go with the Canadian model with the solid reputation and tow it around behind the Kubota.

Boy - when they say SHAFT they mean it!

I bought a similar shaft from AgriSupply this last summer for $360. But it came with a FREE Posthole digger attached

 

[hr3]

6. Yesterday in Smiths Falls I looked at a relatively new Generac cabinet unit sitting at the back of the TSC store (returned because of a missing part). The cabinet was already rusting. I have no information to suggest that these units are durable in the long term, and a bit to suggest the contrary.

Doesn't make sense ?? New unit "the gray ones" with rust and never installed ?? The missing part I can understand .. I once saw a HD employee take an oil filter off a unit to give to a customer because they were out,, " what a mess he made"...