Propane Generator Questions

Runner, if you read my post it addresses several of the issues you raised. Generac markets the cheap stuff through Northern Power, Lowes, Home Depot, etc. The commercial units are sold through full service distributors. As for engines, a 4.3L GM used intermittently, fueled by propane or natural gas will probably still be around when the owner has passed on. The engines in the Generac commercial line, such as the 4.3, are solid. A friend has a 4.3L in a 92 S15 Jimmy that has 220,000+ miles. The engine doesn't use any oil.

A Lister diesel setup for propane or natural gas will last longer than that. As long as the battery has the stuff to crank the diesel fast no matter how cold it gets, the diesel will start. Using propane or natural gas to fuel a diesel eliminates the gelling problem.

Darren - just echoing some of what you said, but....

The generators we have at work, are all Generac commercial diesels (except one Onan) These range from 50kw to 300kw single and three phase, package units on 550 & 900 gallon tanks. They are junk - period. Three & four year old generators, none with more than 70hrs, and we're replacing thermostats, water pumps, charging units, coolant, fuel & oil lines, drifting freq & voltage. Radiator fan shafts that tear up the front of the units. Why would they run a fan shaft THROUGH the radiator??? Whatever antifreeze they stuck in these things, we're looking at rodding out radiators or replacing next.

If you really like them, I'll talk to the boss, we've gone through 3 companies with service contracts - everyone hates these things - maybe we could get you the service contract! The only genset we have that's not diesel is a propane 454 cid unit that has cost us a fortune to maintain. The controls change from year to year, the "generac" parts cost 2-3 times (you have to figure out "who" really made the engine and then order what you need).

If the folks building (assembling) them won't buy them, why would you? Generac has made a reputation of producing the least expensive unit on the market, with whatever they can scrape together. We have Hino, Ford & ???? diesel engines on these things, it's like they went to the 'surplus mart' for engines.

If these are "commercial" units, they should be called ultra-light duty.

Lister is not in the same class as these diesels - they are the champion of gensets, the only diesel I'd recommend. Plus a whole lot quieter. Again, echoing most of what you said, but other than a Lister, I'd take a propane unit over Gasoline in a heartbeat.

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Bill

For a look at Lister and other diesel generators

http://www.allworlddieselgen.com/

Shell out the $$$$$

Kirk! I've worked on, around and with propane powered engines for over 30 years. I own a small 3 kw genset also converted to burn lp--butg just as an emergency power.

My recommendations may be a little different than most but considering your situation and location--propane is really about the only choice to make. A unit in the range of about 10kw, COPPER WOUND, and a workin speed of 1800 rpm. Make sure you have an electronic voltage regulator on yours. It'll keep the voltage/current constant where it won't harm electronic equipment. Most of the small dudes are 3600 rpm and will shake their engines to death in about 20 hours or so. I only use mine for emergencey's and don't count on it to start ---ever!

I'm presently buildin up a genset with an older 3kw--3600 rpm alternator that the enigne died on. Beltin it up the the flywheel of a 6 cyl chevy engine and "gearin" it with a belt/shiv combination where the engine can run about 1200 rpm and the alternator runs at 3600. The reason I "ggeared" it to run at 1200 rpm is because of the expensive shivs I already had. I also had the chevy motor layin around and what good is an alternator without an engine!!!Don't know how it'll work but seems to be an option vs. the old way.

With a slow speed unit, constant propane vapor from the 500 gal tank, electric start and an auto transfer switch you should have a reliable, long lastin system. Spend a few extra bucks and make sure you get something you can count on when it's needed.

If I can be of any help--just holler. I don't know it all but I do know a bunch. old hoot.

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"Therefore be ye also ready for in such an hour as you think not the Son of Man cometh!" Matt. 24:44

That's the beauty of this place. Sooner or later someone comes along with the facts. I'd thought the commercial Generacs were worth the money. I know better now. Although the Lister-Petter gensets have a long-standing reputation for fantastic longevity and quality, to my knowledge, they don't make anything larger than maybe 15KV. So for something larger, what builders has your company found that sell a quality unit?

CAT.......Also, Onan makes a 3 cylinder diesel rated at 12.5 kw with a pure signwave output for 7600 from colorado standby.....fordy

Darren, I once had 2 Onan 3kw, twin cylinder, gas, 1800 rpm units that were made back in the 50s or 60s. Those things weighed a ton, but right up to 3kw, they held steady on freq & pretty darn close on voltage. They were not brushless alternators though...

The biggest problem in generating your own power, A.C. that is, maintaining frequency and then voltage. A light load, the engine races, frequency jumps to 62hz or more, then a load (like your well pump starting), and the frequency drops well into the low 50hz range. The worst offenders are these little 5kw units you mentioned in an earlier post - the price looks good, but stick a frequency counter on it, and watch it jump all over the place. This is what KILLS electric motors! (most digital multi-meters in the $100 price range now come with a frequency option - Fluke 77, etc.)

The belt driven idea works great for turning the thing, but without a sensitive governer to maintain engine/alternator speed - you got the same problem. My brother tried to hook up a 25kw unit to an automatic transmission on an old van chassis, he figured the engine could "just idle away" while the alternator hummed and churned out the power. 25kw of unusable power, frequency and voltage all over the place.

I'm sure Old Hoot as got something to fix that nasty speed problem, but if you belt up an alternator 2:1 off an engine (alternator runs 3600, engine runs 1800), every "error" in engine speed is DOUBLED to the alternator - doubling the frequency error of a 2 pole alternator. If you've worked on 'em, you know exactly what I'm referring to! (lost part of a finger experimenting with one as a teenager)

I have no idea who makes a good engine. Cast iron seems to last the longest, my 28yr old 20hp Wis. Robin was a REAL find, they don't make them that tough anymore. Old Hoot is absolutely right about copper windings! Even a burnt up alternator can be rewound with copper - just get done with the highest insulation rated wire. Who knows, manually rewinding sometimes yields higher outputs!

If I came across a 4 pole (1800rpm) 12kw brushless alternator - I'd jump on that thing in a heartbeat, then I'd look for an engine with a huge flywheel to run it.

No one has brought it up yet, but, Kirk, another option is to go DC, charge batteries, and use an good inverter to run your Dialysis machine. In my line of work, all our equipment runs off of 48vdc batteries. We use rectifiers (battery chargers) to convert 1 & 3 phase power to charge the batteries. There are _no_ power interruptions without someone getting fired.

check out http://homepower.com/ for ideas... Their magazine is well worth the it, these guys shunned the grid from the start.

http://www.realgoods.com/renew/index.cfm all kinds off the grid, back up power systems.
http://www.xantrex.com/products/supercat.asp?did=285 for inverter/chargers

This stuff has come so far in the last 5 years, the power they produce is cleaner than grid power.

sorry for all the long posts!

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Bill

Hey Runners! Yeah, I'm a figgerin on usin an Onan, brushless alternator and usin a 2" shiv on it and an 8" on the engine. Rpm will be close to 1200 but we won't know exactly until it's hooked up and makin juice. A 3:1 will get it close and we'll stabalize it with a mechanical govenour to start with. The tngine don't have to turn exactly 1200 but the alternator has to turn at 3600.

The engine is already set up for straight propane and also is a Jasper rebuilt engine.

I also have an OLD Onan [1948 vintage] used for Military use. A 5 kw, 120 output hooked to a Ford tractor motor [8n]. Heavier'n a battleship but its built like a brick ----house! I'll let ya'll know how things turn out--if they turn out!!! oldhoot.

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"Therefore be ye also ready for in such an hour as you think not the Son of Man cometh!" Matt. 24:44

OldHoot, if you can, go with a couple of belts, and large pulleys! The smaller the pulley, the more chance of belt slippage. That's how I lost part of my 3rd finger, trying to pull the alternator tighter - finger slipped inside and hit the fan. Calmly walked upstairs, told my mom, "I need to see a doctor" - didn't 'register' till she saw blood dripping, and SHE'S the one that nearly passed out! I could hardly stop laughing, and made a bigger mess!

Let me know what you do for a governer - pics or descriptions, that's the really tricky part! A big flywheel helps smooth out the hard starters (motors), but something's gotta regulate alternator speed... the next problem is voltage, but I'll bet you've got that handled already.

Just had a brainstorm.... careful... what if you could add flywheel weight to the alternator, where you really want it? ...Press a new shaft onto the alternator, making it a double shaft unit, flywheel on one end, belts on the other...?

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Bill

I'm usin a large plate steel that will mount directly onto the engine flywheel and bolt where the pressure plate bolted. A Shaft centered, welded and balanced onto that plate. The 8" shiv slides onto the shaft. I would like to use larger shivs but these are very expensive and I already had these. Came off of oil field equipment. The 8" is a 4 "belter" and will try usin two for the alternator and two extra for an air comprossor.

I will start with a govenour from a stationary engine with mechanical linkate. I don't know how all this'll turn out as it's a hillbilly way of engineerin!! Try and see what happens!!!! If it works--fine--if not--back to the mind exercise!

I'm kinda just lettin things go right now because of the weather. Cold and snow outside here in S.E. IL. old hoot

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"Therefore be ye also ready for in such an hour as you think not the Son of Man cometh!" Matt. 24:44