Experience with Mil Surplus Diesel Generators

long-shot

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I'm looking for some help with backup power for the house. I am pretty much sold on diesel for a power supply and I'd like to have something in the 8-10KW range supplying 240v.

My limited research has shown a generator that is liquid cooled and runs at 1800 rpm instead of 3600 rpm has a better chance of success.

My definition of success would be something that is easily portable with a trailer or tractor for use on our home/farm or close family members. I would like a unit that can run 8 hours a day for periods of 2 weeks during periods of power outages.

I'm a relatively handy person and would gladly perform routine maintenance and run the unit monthly to ensure it's ready when needed.

Can these requirements be met with a mil surplus generator? Comment away.

Thanks in advance.

jeff
 

crumpmd

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Oct 28, 2007
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Re: Experience with Mil Surplus Diesel Generators

Not likely to find a diesel generator that runs at 3600rpm.
The milsurp genset my parents used to have had the same engine as a willys jeep and was converted to natural gas. The electrical part of it was very robust, and even at 40+ years old would generate a stable current.
Check the windings and run time on it. Diesel consumption is a factor. I choose natural gas with a propane backup and it can be converted to mogas if needed. But it runs a GM engine and is loud. But at 40KW I am not bitching. It will run everything I have and then some.
 
Re: Experience with Mil Surplus Diesel Generators

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: long-shot</div><div class="ubbcode-body">Can these requirements be met with a mil surplus generator? </div></div>
Just make sure any Mil surplus unit that you are getting is an A/C 60hz machine, uncle has many DC, and lots an lots of 400hz ground power units he is trying to pawn off.

There are 3600 RPM Diesel unit's in the civi world, most are from china,...
If you already have a tractor, you might think about a PTO generator, that runs from your tractor. Just be sure to have enough tractor HP to pull the generator. 2.25 tractor HP for every KW of generator is a good rule to follow. Generator PTO inputs of 540 an 1000 can be had w/540 the most common.
Do not buy anything Generac.
Katolight, (now known as "mtuonsiteenergy") or LEROY-SOMER would be good choices.
Generators are like cars an horses, options are only limited by the wallet, and you can buy hay before it goes thru the horse or after, the choice is yours.

If your looking for true quality, air cooled Lister Petter diesel with either a Stamford-Newage, or Marathon alternator, an ECU controls.
 

Clark

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Re: Experience with Mil Surplus Diesel Generators

My father once calculated that a diesel generator could power the home and the cooling system could heat the home. The savings would pay for the cost and maintenance of the system.

He never built the system.
All those years, we could have been listening and smelling a diesel 24/7.
 

Greg Langelius *

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    Re: Experience with Mil Surplus Diesel Generators

    In 'Nam, I operated diesel generators. We had trailer mounted Detroit Diesel 3-71, and 4-71 powered units, all running at 1800 RPM.

    By and large the 4-71's were the predominent ones, rated at 60KW. They outputted 3 phases, so 240 volts was not a problem. They were relatively trouble free. We shut them down daily for oil level checks, and changed oil every two weeks.

    The only tricky part of engine maintenance was with replacing fuel filters, since they wouldn't restart until every bit of air got purged from the fuel filters/lines

    Another issue was that if a large load got cut suddenly (like when incoming rounds sheared feeder lines), a backlash current surge would overload the regulator circuits and blow the diodes. We cured this by modifying those circuits with quick-blow inline fuses. This could have a bearing on how switching is performed when going on or off the commercial net.

    I am sure a more modern version of these very common generator sets is currently in use.

    Sizing a generator to its load is not as straightforward as one might think.

    IMHO it makes good sense to use a unit at only a fraction of its rated power. Running them at constant full load is rough on the units, and fuel consumption is pretty nearly directly related to load, so running a bigger one on a fractional load carries little, if any, excess fuel consumption penalty; and load surges, like ones from electric motor startups (A/C and Refrigeration are significant part of this issue), need to be considered when rating loads.

    Industrial/commercial backup/standby generator sets are usually installed in soundproof enclosures and well muffled. A tall exhaust stack can go a long way toward reducing fumes, but these units don't fit well into a residential settings.

    When I applied to the VA to obtain a hearing aid for my hearing loss, I stipulated my year-plus long 24/7 service as an operator of a tandem multiple generator set installation (we had four 60KW units operating the same net, running parallel), and no further justification was required. It all adds up.

    Greg
     

    HPLLC

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    Re: Experience with Mil Surplus Diesel Generators

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Greg Langelius *</div><div class="ubbcode-body">In 'Nam, I operated diesel generators. We had trailer mounted Detroit Diesel 3-71, and 4-71 powered units, all running at 1800 RPM.

    By and large the 4-71's were the predominent ones, rated at 60KW. They were relatively trouble free. We shut them down daily for oil level checks, and changed oil every two weeks. The only tricky part was replacing fuel filters, since they wouldn't restart until every bit of air got purged from the fuel filters/lines.

    Sizing a generator to its load is not as straightforward as one might think.

    IMHO it makes good sense to use a unit at only a fraction of its rated power. Running them at constant full load is rough on the units, and fuel consumption is pretty nearly directly related to load, so running a bigger one on a fractional load carries little, if any, excess fuel consumption penalty; and load surges, like ones from electric motor startups (A/C and Refrigeration are significant part of this issue), need to be considered when rating loads.

    Industrial/commercial backup/standby generator sets are usually installed in soundproof enclosures and well muffled. A tall exhaust stack can go a long way toward reducing fumes, but these units don't fit well into a residential settings.

    When I applied to the VA to obtain a hearing aid for my hearing loss, I stipulated my year-plus long 24/7 service as an operator of a tandem multiple generator set installation (we had four 60KW units operating the same net, running parallel), and no further justification was required. It all adds up.

    Greg </div></div>

    In 2009 one of our duties required work for 8-12 hours at a time near a generator that was in such awful shape that it would only run with all the sound insulated doors open so that it could cool. In Iraq the heat and dust are terrible for machines.

    Generators are very loud when the pannels are open.
     

    Greg Langelius *

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  • Aug 10, 2001
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    Re: Experience with Mil Surplus Diesel Generators

    My situation was that I was quartered inside the generator shed, which ran the four generators 24/7. The units each had a muffler which could only be considered a token effort.

    They were still loud enough that incoming mortar/artillery would begin with probing to locate crucial areas by waiting for the sound of the generator to die. Barrage fire would then follow.

    So we would wait for the probing rounds to find a barren area and shut down the generator set(s). Usually, enemy barrage fire would then drop on empty terrain. Sneaky, but effective.

    No provision was made for hearing protection back then. We would insert cigarette filters in our ears for a little relief. No OSHA issues back in '66.

    Greg
     

    Clark

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    Re: Experience with Mil Surplus Diesel Generators

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Greg Langelius *</div><div class="ubbcode-body">In 'Nam, I operated diesel generators. We had trailer mounted Detroit Diesel 3-71, and 4-71 powered units, all running at 1800 RPM.

    Greg </div></div>

    When I was in high school, I had a friend on a water point for a fire base in nam.

    Some colonel landed his helicopter, found only my friend working, and promoted him to acting jack.
     

    sr15match

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    Re: Experience with Mil Surplus Diesel Generators

    You can have a fair set-up foryour house with little effort. Mil surplus gens are ok at best but a MEP-804 is in your range and most have enclosures on them keeping them really quiet when running.

    If you can I suggest getting a newer commercial unit (Cummins / Kohler / ect) that runs off natural gas or LP. Cleaner running, no issue of fuel seeting in the tank (and day tanks on the MEPs) / having to put additives in it making sure it'll run when you want it to. Besides getting parts when you need for a commercial unit is much easier than some of the older MEP units that are floating around. Trust me, I'm prior USAF power-pro and still do power systems set-up and maint everyday for a living. Even over here in A'stan where I'm at we've gone to all commercial units.

    If you're going to run an ATS with your set-up then the smaller MEPs aren't an option as most dont have an auto-start option. If no ATS then it makes life way easy.

    If nautral gas / LP isn't an option the yeah diesel is a fair choice. 1800rpm is the standard for a diesel as that's what produces the 60Hz you're looking for. Check the panel in your house and see what you're drawing with a good clamp-on amp meter, calculate that to Kw and then see what you really need vs want.

    You have tons of options! Good luck on your search.
     

    Switchblade

    muf kin poser
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    Re: Experience with Mil Surplus Diesel Generators

    Diesel generators are superb. If you plan on running one, insure it has electrical start and a Ether system for winter...most use will be during winter/power outages. Make sure you run the thing monthly and do proper periodic maintenance(Scheduled Maintenance). This will insure proper reliability when needed, and prevent most Unscheduled Maintenance call outs. I would also advise adding storage batteries with a converter for DC ~ AC. I wouldn't think a home would use a 6-71 powered generator, but shoot, you want one of those big Detroit Slants, have at it!
    Really though, the most effective generators I have seen lately were the small 10k's we used in the snow or other training. They can power an entire Division Level FTX for S1's through 26's as well as power a mobile dfac, and other random BS. Your home will probably underuse a generator of that size.
    For total reliability and load, a generator loves to run at pushing 2/3 - 3/4 of it's rated capacity. Anything less and it's not really working. Brushes and circuit boards like to run in a little heat and 2/3 rating about heats it just right amd makes it happy. Just a little something I learned way back in the Corps about power supply geberators from itty bitty ones to the big trailer mounted ones. Troubleshooting them is a breeze if you know basic electronics, new computerized ones, stay away from them if you want to be able to DIY repairs. KISS and you'll be fine
     

    ArcticLight

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    Re: Experience with Mil Surplus Diesel Generators

    When I was in MI we had a 5 ton electronic shop - had to keep it operational (Microwave, coffee pot, TV etc)...so we had a 5kw on it..

    Was not hard to maintain either.

    I'd go mil surplus if I had a farm and not worried about the noise, definitely louder than civilian models...