MEP-003 vs MEP-004 House backup power

[Corvette1974]

Hello.

I currently have an MEP-003 hard wired professionally to my house through a transfer switch, so it can power the whole house. It did great over 4 days of use when Sandy hit.

Here's the thing though - If it is possible, would you guys suggest getting an MEP-004 and then reconfiguring it for full 1 phase output and using that to power the house instead?

The reason I bring this up is we were powering the WHOLE house. Literally everything. We had electric water heater, range, well pump, space heater, lights, you name it it was on. During normal use, it was hovering around 50% load. BUT- during high use it would routinely get to 110+% load and run like that for not too long, but more than a few minutes at a time. I know this is a military generator and can handle that for some time, but we did trip the generators breaker one time because we were using everything and my sister put on her curling iron. So we are definitely at that limit, and thats not even with the "need" for A/C. So I was thinking...


Is it better to run it at 100% plus load for 1/4 of the time, with about 3/4 of the time at 50-60% load, thus avoiding any real wet stack situation but also putting an overload onto the whole system, OR would it be better to run less of a percent load on a larger gen such as the 004 and run like 30-40 percent most of the time, but when a full load is put on it would be at around 90-100% instead of being overloaded?

Essentially - Stick with what I have and whoop this 003 (she loves it BTW - Very evil sounding under 100 plus percent load ) or do I upgrade and get a 004? My dad is looking into more because of situations like Sandy, we need to be prepared. We also just bought a MEP-015, still gotta do a post on that!

Let me know what you guys think!

Thanks,
Will

 

[gimpyrobb]

You are running the 003 the way you should. The 004 will not work as well.

 

[Corvette1974]

Alright sounds good.....wasn't sure what they liked when it came to being ran. I knew I liked these military pieces, They love to work hard. I still might end up getting a 004 and / or other military generators. So we'll see.

Will

 

[gimpyrobb]

If the 003 is working well for you, I'd say stick with that model for parts commonality, just my thoughts. Somewhere I heard that the 004 run in single phase is only rated at 10kw, same as the 003, but you'll have to watch balancing the load more closely.

 

[Corvette1974]

Oh I wont get rid of the 003 anytime soon. It is basically perfect, and if it aint broke dont fix it! I'm mainly talking about future expandability of the system and what other options are available. Of course things like the MEP-005 are way too big, but the 004 seemed like the "next step" if we ever truly need to upgrade.

I am aware of what you are saying with the only rated at 10 KW thing with the 004. I thought that is why you needed to reconfigure it for pure 120/240 single phase instead of 120/208, because when it is reconfigured you get all of the available power, not just one legs power. PLEASE correct me if I got this twisted somehow! Because if that is true, it is basically pointless to use a 004, unless that is all you have.

Will

 

[gimpyrobb]

I don't know enough about gensets to tell you. I will let one of the other guys post up that really knows these things.

 

[michigandon]

Drawing power from just one phase on the MEP004a you can only get about 9kw. However, you can get about 14KW by doing the sewerzuk mod.

I was planning on getting a 003a, but now leaning towards a 004a due to the "bang for you buck" factor, and the fact that we currently reside in an energy hog of a mobile home.

Hate these "all-electric" dwellings that are all-too-common down here.

 

[Isaac-1]

I would vote MEP-003a and try to work on your load management some, as the MEP-004a will be more prone to wet stacking since it is a water cooled unit (runs cooler), the other down side of water cooled is that water pumps have the bad habit of going out at the wrong time with little or no warning (you also have hoses, radiator, radiator cap, thermostat, etc. to worry about although those are generally easier to patch/fix during an emergency). I am dealing with it right now with the John Deere engine on the Kohler commercial diesel generator I have installed at my elderly mother's house. I went to do its monthly test run last weekend while visiting for Thanksgiving, and 25 minutes into the 30 minute test run powering the house it shut down on low coolant, I went out to look at it and antifreeze was gushing out of the water pump.

 

[michigandon]

I think I could keep plenty of load on one to avoid the wet-stacking concern, at least in the dead of winter or summer when the heat or A/C is wanted. The electric furnace in this place SUCKS...literally as well as figuratively.

The water pump failure however is a fair and legitimate concern that I hadn't given much thought to. Might be a good idee to keep a spare on on the shelf. Can they be had from any of the surplus vendors?

I have a 5000W Chicom diesel unit that will be relegated to secondary duty once I get an MEP on the premises, so odds are good that I wouldn't have to go with NO power for very long.

 

[SCSG-G4]

If you are worried about enough power, get another 003 and split the loads between them. That and a little better load management will get you through the situation much better than the 004, and you'll always have a spare!

 

[Corvette1974]

Ok so the sewerzuk mod *will* allow most of the power out of the 004. And I understand the whole load management thing.....but I'd rather just have everything powered and not have to worry about it (I could do load management with my 015, but that wouldnt be any fun hahaha). It's not that the 003 had trouble, but I did end up finding it's limits! Very ironic too, my mom was like so how much can this thing take and I responded with everything you can throw at it.....until it either shuts off or blows the breaker - half an hour later I was showering and it went black in the bathroom. Knock knock knock "power's out", by the time I got out my dad had already killed some breakers and re flipped the breaker on the gen. I guess that's how you find the limits- it mustve been 120+ percent because it was puling 110-115% all day long.

Water cooling system parts are a very real concern though.....are the 004 and up parts prone to breaking? Like I wouldnt worry about my bosses 1960 John deere (probably original) waterpump going, but is there a bad design with these units? And like asked before, can you get the parts?

And for the wet stacking, I dont think I'd have any issue really. If for extended periods we were pulling 10 plus kw on the 003, and even overloaded it, then when it it A/C time or even deeper winter again (it wasnt really that cold when sandy hit), we'd be putting probably even more load. Essentially I'm saying, a 003 is no problem to overcome in our house, so "5" more kw couldnt hurt! How long does the wet stacking process take to set in, and un do?

Please let me know, at this point I'm just trying to learn everything I can!
Thanks,
Will

 

[Corvette1974]

And also, I'm not worried about wet stacking, because all I have to do is turn on the A/C and everything else and that'll do it to at least 15 kw. I can also (and should also) build a load bank.

Will

 

[rickf]

I would be careful running at that kind of load (110%) too much. It IS a 30 year old generator with the same age wiring. I love your "Needs".
I need my well pump, a couple lights and the fridge. Period.

 

[Corvette1974]

Well see that is what I am getting at, I'm sure it can handle it, but using it like that for too long cant be good. That's like full throttling my Corvette for hours at a time.....

My "needs" are legitimate. My family was fed up with having to replace the basement due to flooding three times, and sitting for weeks in no power. So I figure, if you're going to do it, do it right and power everything. Needed or not, just do it 100 % or not at all.

Whole house off grid ability is one thing my family definitely wants to be able to do, for various reasons. That is one reason why I was wondering about running the 003 at such high loads I dont want to just ruin it over time and then when we really need it (SHTF) we will be stuck....

Just my .02

Will

 

[edgephoto]

Neds and wants are 2 diferent things. Corvette man wants to run everything without any concerns. SO go for it and buy the big machine. Do a trial run on a weekend and see if wet stacking is an issue. if so then worry about load banks, etc.

Personally my choice is to go with a unit that can run all my common stuff. Lights, computer, TV, etc. Then I just pay attention to the big loads like toasters, microwaves, ranges, water heaters, etc. My petrol Generator is a 7500W model. I have city water so no well pump and a dry basement so no sump pump to worry about. I leave the hot water heater off until we want to shower then turn it on an hour or so before we need it. I am more concern with fuel consumption than needing everything on all at the same time. I want to have 7 days worth of fuel on hand. I run the generator 12-14 hrs a day during an outage. So if I use a 1/2 gallon per hour I need about 49 gallons for a week. So one drum of diesel will do it. If I go with a 1 gph or more unit I would need 2, 3 maybe even 4 times the fuel on hand. Storing that much fuel starts to draw attention and becomes a full time job to maintain a clean and fresh supply. Not too mention in a 7-10 day outage the money it costs. My regular electric bill is about $100 per month. At 1/2 gph it costs about $25 a day to operate.

 

[jbk]

you will have more than enough motor with the 004 (44hp) as compared to the 003 (18.5) so you will be limited by the head. with the mod. about 13kw on the 004. your 003 will do 12kw. so you might think about the 005 you should be able to get 25 or so out of it with the mod.

 

[Corvette1974]

Hmmm so the mod doesnt allow the full output? That is definitely a consideration, because the 005 is way to big that would wet stack like crazy.

You guys have to understand the 003 works fine. But I'm also looking out for its well being and plus, is it ever a bad thing to own more OD equipment? If the 004 could only put out 13 KW then that is basically pointless, but if not then we may be onto something.

And for fuel use, the 003 costs about $25 a day to run (being off when people are sleeping). We are probably going to get a 250 gallon fuel tank sometime.

 

[Corvette1974]

This is true, but the same could be said for the 003 vs 002. I dont *need* the 003 but why would you get the smaller one when you know that one thing alone (a water heater) will draw the "full" capacity of the 002. I could just use my 015 to power a few lights and a fridge. But you might as well just make it power everything. I have the 015 so I can do work on the 003 if it were to ever go down, or do remote jobs that dont need or cant use the 003.

My Coleman gas lanterns work just fine, I dont even need a genny, like we've been doing for years.

The generator is a luxury that we are very grateful to have. It makes living during power out conditions more bearable. Trust me its not a home free solution. You need to monitor the generator and home - it is constant work. It is not like having line power.

I'm trying to gather some information on whether it makes sense to maybe upgrade generators. Or even whether the 015 makes sense to purchase outright, when like stated, you can only get maybe 1 more KW out of a package that weighs twice as much and is more complex. This is just a "MEP think tank" right now. I'm not trying to be hasty and buy something that doesnt even make sense to buy.

Will

 

[Isaac-1]

The problem with the MEP-004a is that it was never designed to provide full load capacity in single phase mode, in theory a safe bet is that the generator end is good for about 70% of the 3 phase output capacity (a little over 2/3 of the 3 phase rating due to the added cooling capacity of the under used windings). If we work from a true 15KW rating that works out around 10.5 KW, anything over that is making assumptions about the tendency of the military to under rate design, etc. It may be good for 12KW, or 13KW, or maybe even 15KW we just don't have enough design information to know at least not until someone systematically runs one, upping the load ever few hours until the point of failure, and even then there is limited information to be gained from a single datapoint.

Ike

 

[storeman]

By golly, I hope you have at least 500 gallons of diesel stored and preserved to get through a 2-3 week period at the rate of usage you describe. If you can afford it and have foolproof resupply, live the good life.

If shtf, I would think air conditioning would be your least concern. Low load on a mep-004 is a wet stacking problem and still consumes as much as load an 003 and twice as much as an 002 at load.

I have a large house (as a couple of members who have visited can attest) but have converted everything I can to propane. Judicious use of propane stretches my 500 gallon supply a great deal. I can provide essentials for my home for 3 months (or likely more) with an 002a off 300 gallons of diesel. I have a well and instant gas water heaters versus tanks, but we do manage water usage, especially hot water. With the 002 we can burn all necessary lights in the house, run the well and the micro, gas cook-top, instant water heaters, gas heat, etc....all on 0.5 GPH.

I don't mind sweating and have lots of blankets for the night time so we can get by with power about 4-6 hours per day split in cycles to support day-time house warmth, necessary communications, battery recharges to support inverters, bathing, freezers and refrigerators. Life can be tough.

Jerry