Gen-Trailer. Sizing?

[Biggles]

I am in the market for a generator. I would like a trailer mounted one since I don't own a fork truck and it would be really inconvenient to get in and out of the truck. my question is how big is too big to use as a back up generator for your average house? There is a local auction coming up and they are auctioning off a pile of MEP's ranging from 5Kw to 100Kw (as well as some oddball smaller DC generators and some really really big ones that I would be doing good to haul home in my deuce)



I want a diesel generator that is trailer mounted and big enough to use as a back-up if I had to. I just don't know how big is too big.

 

[emmado22]

10-15Kw will power a house fine.

 

[v8turbo]

So... the units I see at the auction that have the 60KW,(60 kilowatts, 50/ 60 hertz generator set)... if you have this wired to your house, you could run everything.

Would it be way to much overkill?

Also... anyone know how loud they are?

 

[steelandcanvas]

60KW is way too large, you'd incur the problem of "wet-stacking". 5 or 10KW is a good size to run a house. Also with the air-cooled gensets, wet-stacking is not as much of a problem, the 60KW is liquid cooled. 5 and 10KW are air cooled, don't know about the 15, someone will chime in and let us know. I just bought a 10KW, MEP-003A last year on a trailer, just for that reason of mobility around the homestead, or around our community, should the need ever arise.

 

[Biggles]

So what's better? MEP-002A 003A or 004A? those are the ones that are going for sale that are the right size? What are the differences (besides size obviously) advantages? disadvantages? How available are parts for these things?


P.S. thanks for all the info so far!

 

[LanceRobson]

The 15kW and larger sets are water cooled diesels and are all 3 phase only. Drawing power off two legs to get household power tends to cause major problems over time. Also, fuel consumption is significant. All are mounted on large trailers although there are smaller wheel set that can be used to move them around a shop or driveway.

I think you'll do much better to stick to the MEP-002 or 003 sets or get a commercial set.

There are lots of online resources to help you correctly size a set or to figure out how to cut down your power consumption when using a generator.

Lance

 

[Biggles]

That's kinda what I was thinking, I just had my heart set on an 004 that I saw out there because it was in really nice shape on a nice big trailer like I wanted and it was tan to match my truck already. I was afraid it would be too big though. Thanks!

 

[Isaac-1]

It all depends on your electrical loads, size of the house, and how much you want to run during an outage. Remember the larger the generator the more fuel it will burn even at a light load. For me, I don't mind roughing it a bit and managing loads, a 3KW MEP-701a will handle all of my important summer loads, refrigerator, freezer, a couple of small air conditioners (5,000 BTU wndow unit, and an 11,000 BTU portable), plus a few lights, TV, etc. Of course I have gas heat, and gas stove/oven, so winter loads are even less as all it needs to supply is blower fans for the heat as well as the refrigerator and freezer. In theory I could even heat water (electric), do laundry, etc. by doing a bit of creative load management and turning everything else off while each one ran. On the other end of the spectrum, bought a 30 KW Kohler industrial unit for my elderly mother's house, which is a fairly large all electric house located on a farm with a water well, 3 central air conditioner units (or electric resistive heat in the winter), 3 electric water heaters, and of course electric stove/oven, etc. In the course of typical daily living it is in theory possible to max out the 30 KW generator, for summer loads it will run all 3 air conditioners, plus any incidental loads, like well pump cycling, normal low load cycling water heaters, however to do cooking/laundry requires turning off one of the air conditioner units. Winter loads will allow 2 of the electric heater to run, plus assorted light loads, cooking/laundry requires cutting down to 1 heater, which is usually not too bad, as the house has 2 fireplaces that generally handle most of the heating needs.

Ike

 

[Biggles]

really wanted that 004A but I think that will be oversized for my needs. With 15kw I could turn everything I own on at once and not even come close I think 10KW will allow me to operate as normal without roughing it at all. I do like to overdo things sometimes but I think generator sizing is not the place to do it. So I think i have narrowed it down to the 002A or 003A I wont have to worry about wet stacking with these right? Is one of these louder than the other? is one of them easier to repair or find parts for? I liked the trailers that the 003A's where on a lot more than the 002A's but I don't think that should weigh in too heavily. You guys have all been very helpful. Is there a spec sheet somewhere on this site for these things? lik the faq sheet we have for the deuces?

 

[Speddmon]

there isn't a FAQ section for the generators like there is for the deuce. But the TM's for both are in the resources section. The most informative TM for general data would be the -12 manual. for the 003a it is TM 5-6115-585-12, and TM 5-6115-584-12 for the 002a. Rough size of an 002a is about 51" L x 32" W x 37 H and weighs in at about 1000# wet. The 003a is about 62" x 32" x 37" and weighs about 1360 # wet. There is also a TM for the trailer mounted units, but they are essentially the same as the generator TM's with some extra info for the trailers.

Spare parts can be had for these sets, but they are not the easiest things in the world to find sometimes. And they can be pricey since they are not produced any longer. But, they are also a very robust machine and do not break often. So, with some TLC and maintenance, they should last a lifetime for the average homeowner. Wet-stacking is not as big of an issue with the air cooled units as they tend to run a bit hotter then a liquid cooled set. But in the cold winter months it can still happen, just throw about an 80% load at it every year for about an hour and let it burn off, and you'll be just fine.

 

[v8turbo]

ok.... i had to look it up -

Wet stacking is a condition in diesel engines in which all the fuel is not burned and passes on into the exhaust side of the turbocharger and on into the exhaust system. In Diesel generators, it is usually because the diesel is running at only a small percentage of its capacity.
It is detectable when there is a black ooze around exhaust pipe connections and around the turbocharger. Continuous black exhaust from the stack when under a constant load is also an indication that all the fuel is not being burned - good preventive maintenance is critical for this type of generator application.

 

[Biggles]

I think I am going to go for one of 003A's I think that will do all I'll ever need and not be TOO big. thanks for all the help folks!

 

[v8turbo]

So... would a 30 kilowatt, 50/ 60 hertz generator set be way overkill for a house with AC/Pool/...Etc

or would a MEP-004A, 15 kilowatt, 50/ 60 hertz be a better fit?

 

[Isaac-1]

It depends on the house, I bought a 30KW (rated at 33KW single phase) Kohler diesel generator from GL for my elderly mother's house last year, it is a fairly large all electric house on a farm with a water well, etc. This generator allows her to live life as normal without need to worry about much load management. I say much load management, as it is possible to overload the generator if you really try (all 3 central air conditioner units running (or 2 of the 3 heaters in winter), running water from all 3 water heaters, electric stove and oven on, along with clothes dryer and well pump running). In the real world such things are possible, cooking dinner, while doing laundry, and someone taking a shower in the guest room as that could draw water from all 3 water heaters, but easy enough to avoid with a few simple rules like heat off while cooking, or no laundry and cooking at the same time. The problem with sizing a generator is the other extreme, while at my mother's house a couple of weeks ago, I test ran the generator after changing out the radiator hoses, it was a nice day with the high in the upper 60's so no heat, no air conditioner, etc. and the full draw on a fairly typical spring afternoon a few light bulbs, refrigerators, freezer, etc. was around 2-3 KW. It just comes down to what do you need to run, and how "normal" do you want life to be, for me with gas heat and gas stove/oven a 3KW MEP-016B is plenty, it can keep the refrigerator and freezer cold, and run a couple of small air conditioners for a cool room or two to sleep in during a summer outage, or run the blower motor for the gas heat in the winter, but I don't mind doing load management (turn off everything else for an hour to hook up the electric water heater for a warm shower, after a couple of days without power, etc).

Ike

 

[Carl_in_NH]

And don't forget fuel consumption; the rule of thum is roughly 1 gallon per hour for every 10 kW of generator power - loaded or not. A larger generator equals more rotating mass - both engine and generator head; you pay for that in fuel whether or not it's loaded.

While there's a wide variation in the amount of fuel consumed, this rule of thumb will serve you well for planning purposes. It's important to know how much fuel you need to have on hand during an outage - or how many trips to the supplier you'll have to make while the power is out.

The 'right size' generator becomes even more important when you consider this operational cost. Don't buy a lot more than you really need for the application at hand.

 

[oshpunit987]

I have made several trailers out of the rear axle of Dodge Caravans. An MEP-002 or 003 aren't very wide so you wouldn't have to alter the width of it. If you can weld it might be a little cheaper than a trailer mounted unit.