Milatary Generator

[fitter1]

I'm looking at a mep 802a diesel 1800 rpm water cooled 5kw reconditioned generator with 82 hrs. Any used equipment is a crap shoot. My question. is a 2cyl diesel more noisy than a 4cyl? The seller has both and the 4cyl. runs smoother. He is repairing another 5kw that I can compare it to but the knocking sound concerns me. I do realize diesel engines all have slight knocking noise to them.

 

[daybreak1998]

Howdy,
There are numerous video's online which you can watch and listen too. Just search up for MEP-802A and MEP-803A.

The MEP-802A is a 2 cylinder diesel engine. The MEP-803A is a 4 cylinder engine. Both engines are the same, except 2 and 4 cylinders. All the parts are common between the two.

It depends on what your power requirements are. The military generators are at 5kw and 10kw. That figure is very conservative. The PF is .8 for each.

 

[fitter1]

Yes, I understand that and done so, but why should a 2cyl. be loader than a 4cyl?

 

[Cord]

Don't fall into the trap of getting a generator that is a too large for your application. When underloaded the generator will over fuel it's self and that will result in "wet stacking". I run a 831a which is smaller than the unit you are looking at so I'm not familiar with the 802/803's. On my unit I've found the acoustic enclosure to be pretty effective. Not nearly critical silent, but you can carry a conversation right next to them. In a silent woods I can't hear the unit from 200' away. The ones without the enclosure are OMG loud! The units with the Onan engines are louder than those which have a water jacket because the Onans were air cooled. The Onans were a good engine, but Cummins now owns them so parts are a bit harder to find. That's Ok, with the surplus stuff there is plenty of aftermarket support. That said, sometimes filters can be almost impossible to find. Look into the availability of parts before you buy. Also make sure you are buying a unit that has been loaded tested before your eyes and carries a 6 month + warranty. Realize the stuff that is sold surplus has been picked through by the other government agencies. They get the good stuff and we get the scraps. You can't tell whats wrong with them when they cross the auction block and I've seen some people dump some real lemons onto the retail market.

 

[bdog]

I have a MEP003A. It is loud as crap but I love it. I modified mine to accept spin on canister style oil and fuel filters. The OEM ones are a pain. Every time I changed the oil I had a leak. I run mine to power a mobile office of sorts at work. It runs 10-12 hours a day sometimes for weeks at a time. Never gave me any trouble and most the time it doesn't have much load on it. It runs a full 10-12 hour day on one tank of fuel which is really nice. Only complaint is it is loud. Seriously loud as in you want ear plugs if you are around it. They make some tactical quiet military generators. If I ever replaced mine I would look into one of them.

 

[sodamo]

I have the MEP803a, the 10kw version, not had it very long, but like it so far. Quiet enough, my wife doesn't hear it running.
Go to http://www.steelsoldiers.com/forum.php
And several there have your unit. Do a search and you can learn a lot, probably even videos of a unit running. Several guys on the forum have done lots of troubleshooting and rebuilds. Parts can be sourced as well.

 

[hammick]

I own an MEP-802a that I use at my off grid place. I have flipped on 802a and I currently own an 803a that I am going to flip. The 803a is noticeably smoother and maybe a tad more quiet. Don't buy more generator than you need. I addition to spending twice as much for fuel you will wetstack a generator that is too large. The 802a is plenty quiet.

I just had a muffler fire in an MEP-831a that was severely wetstacked. The genset only had 15 hours on the new engine (tier II reset) but I suspect they used the original muffler which was was severely restricted. The genset was in the back of my truck when it caught fire. Scary deal.

 

[RoyKing]

I just bought mep-802a 6kw and friend bought mep-804b 15kw, found a guy who buys and fixes them and sells them with guarantee he'll fix for free with used parts, or free labor you pay for new parts. Getting ready for bad weather and wanted diesel, easier to store fuel 55 gallon drums. They are not small or light but are on fork lift pallets fairly quiet. Mine was cheaper than the 3kw Honda inverter. Last time gas was hard and dangerous to get. When I showed up with two 55 gallon drums and started filling them in bad part of town some folks started to complain. I accidently unzipped my jacket so my so my 1911 on my hip showed, but don't want that again. If storm is coming I fill three 55 gallon drums with agricultural diesel, should give me 30 days.

 

[Industrial Toys]

Seems like some people have some nice generators. For the same KW, I'm surprised that there are those wide variations in cylinders for the same cooling method and rpm. Two cylinders seems a bit cheap, three would be better, but given the choices, I would go with four. To me, it would be a smoother running engine. What makes are the engines? That would actually help me make my mind up even more.

I have a three cylinder Kubota 7.5 kw Onan that runs nice, but an Isuzu Onan 12KW four cylinder that runs even nicer! Both 1800rpm.

 

[RoyKing]

The engines are Onan 2cyl 6kw 4cyl 15kw or a turbo charge 3cyl on a 15kv 804b. There are forums on these Gen sets, made to outrageous mil standards EMP proof, but not light 800# for 6kw and 1800# 15kw. Both are quiet enough running in garage you could talk over them 73dba. Here is the link
https://cdn.greenmountaingenerators...Fermont-Sales-Brochure-and-Specifications.pdf

 

[RoyKing]

What I like is these are brushless and need to be excited so closer to alternators. You put a load on them then tweak the frequency. and voltage 120/240/208 3 phase and you can draw full power on a single 120 leg. They also run off aux fuel tanks. A separate fuel pump and filter refills the on board tank. So you can change drums while running. No electronics all relays and diodes.

 

[Industrial Toys]

If the ENGINES were Onan, I would not touch them. Not at any price.

If you ever had dealings with Onan on Regular run of the mill stuff, you would probably understand my position.

 

[TractorGuy]

I've had a 10 KW MEP 803A for a couple of years. Great investment so far.

That 804 your friend bought is 3 phase only. The 802 and 803 are switchable between 3 phase and single.

You may want to join the steel soldiers forum. All the info and support you need for it over there.

 

[Industrial Toys]

Someone may wish to correct me, but I believe there is no way a three phase generator will deliver full rated output into a single phase load.

 

[RoyKing]

They do written right on the side plates and the 804b is wired the same way, all the manuals are on the green mountain. I spent days reading the forums and lot people like Isuzi Onan motors, the problems I've read is mainly cause by sitting outside an getting water down the exhaust. Personally I don't think you can bye a better built Gen set.

 

[TractorGuy]

Someone may wish to correct me, but I believe there is no way a three phase generator will deliver full rated output into a single phase load.

The 802 and 803 are designed to run at either but they deliver less current in 3 phase. There have been people that try to cheat a 3 phase only and use two legs. Not only is it not a balanced load but it is only 2/3 output.

Here is the data plate on my 803. It delivers 104 amps at 120V 1PH, 52 amps at 120/240V 1 PH, or 34 amps at 120/208 3PH.

I have placed a resistive load of 13,500 watts and it held it fine. I typically load it to 10,800 for a couple of hours every month to keep it in good shape and make sure it will run when needed.

 

[Industrial Toys]

I can't get my head around using only two of the three windings for single phase.

 

[s219]

I have placed a resistive load of 13,500 watts and it held it fine. I typically load it to 10,800 for a couple of hours every month to keep it in good shape and make sure it will run when needed.

What do you use for a load?

 

[RoyKing]

Here's another little fun fact the 804 will generate 416 volt single leg for commercial lighting. What I believe they done is put multiple windings in the field. Like 416 requires to rearrange some shunt bars, essentials reconfiguring the field/stator. You can also parallel these machines.

THE 804A IS 3 PHASE ONLY NO 240V

THANKS FOR MENTIONING, will check AC TO see if rated 200/230/240 or 220/230/240 big difference.

 

[pmsmechanic]

What do you use for a load?

I've seen rebuilt generators broke in by running wires to three rods in a brine solution in a plastic barrel. There was a mechanism to raise and lower the rods to vary the load.