MEP Sizing Help

[eatont9999]

Hello everyone! I have been lurking around here for a little while picking up tidbits of info on the MEP 8xx series generators. I have always wanted a backup generator but never really been in the position to get one or use it properly. We are buying a house out in the country (hopefully closing in June) and I finally have a place to put one and install it. I'm not sure how reliable the co-op electric service there is but considering EVERYTHING about the house runs on electricity, I don't want to be without it for very long. The property is located north of Fort Worth, so storms are common in the spring and sometimes early summer.

In my head, I have spec'ed out the MEP-803A as a suitable set. Now, I may be way off base here, so that is why I am asking people with more experience than myself on this subject. My goal is to power the entire house or as much of it as possible while optimizing fuel consumption. I don't want too much generator and I certainly don't want too little generator. I know about wet stacking and want to avoid it so I have one less maintenance item to deal with.

Here are the features of the house: 1800sqft, older A/C unit, electric heat, one window A/C unit, electric water heater, stove, dryer, well pump, well pump heater, servers and network ~1KW max. I may also use it to power a welder, compressor, etc. in the workshop but not at the same time as the house. The things that have to be on at all times are: A/C or Heat, water heater, well pump and heater, servers, and stove. I have a wife and kid, so creature comforts are to keep them happy.

I have looked at DRASH trailers for auction and though a heater and AC unit would be nice for the shop, I wonder if the genset is overkill. I think they are 15KW. I'm not afraid of Diesel engine work but I want the electrical part to be ready to go.

I hope I gave enough info. If not, I can be more specific. Let me know your thoughts.

 

[csheath]

Not knowing what size AC, water heater, etc. nobody can answer with certainty but I don't think you should attempt to power all the items you want at the same time. Some load management will be necessary.

I can run my 3.5 ton AC and well along with all the normal 120v circuits with my 803A. I wouldn't try to run the range or hot water heater while the well breaker is turned on. I let the well pump up then turn it off while the water heats then I turn the water heater back off. A 50 gallon tank of hot water should last for 3 or 4 showers. The biggest concern will be the starting amps on the AC and well while other high amp loads are running.

A lot of the military gensets in 15kw up are 3 phase only so make sure you research that before considering them.

 

[Bmxenbrett]

I have a 802a. My water heater is a heat pump unit, well is 240v and electric stove. I can take a shower, and use a burner on the stove while both rooms are fully lit up. Your electric water heater is going to consume a huge amount of power. The A/C also could but you didnt state the size.
With what you say you want to run it sounds like an 803 should be a good fit for your house.
Now if you changed the water heater and didnt heat the whole house on electric u might beable to use an 802.

 

[Guyfang]

Until you walk through the house, look at what each and every fixed load is, and maybe measure other loads, (lights, kitchen, that sort of thing) you can only speculate.

 

[Haoleb]

I think you could run your house off the 803 with some consideration to what loads are on at a time. I do not think it will be able to provide enough power for you to go about your day as normal running hot water heater and dryer and 4 burners on the stove and the AC at the same time. Those heating element type of loads consume a lot of power. My load bank only uses three water heater elements to load up the 803 to 100% current capacity.

I am able to run my house as normal and can run anything I want with my 803 but I also have gas hot water and gas range. I have a well pump and electric dryer. The electric dryer elements cycle on and off a lot and that creates some frequency fluctuation. Maybe an online type UPS would be ideal for sensitive equipment when running off the generator.

I think you first need to ask yourself how do you want to be able to function in an outage... Limp mode or turn everything on in the whole house mode?

 

[Dwnorton1]

I have an 803 for my house which in current configuration is near all electric, gas heat. You will need to have some load management involvement. I went with 803 because 804 and up are 3ph units and really didn't need the extra capacity. I tried an 802 and it just required way to much load management and would not start HVAC reliably. That being said I added a hard start kit to my HVAC unit and now I suspect that 802 would have handled it. The extra capacitors help with the locked rotor inrush that the generator did not care for. For me 803 is the best way to go. If I were off the grid I would want a bigger unit as to run everything on demand, but in a backup situation I am not so concerned about ability to run without though, I will just be excited to have cold air and cold beer. Also in long term outage the 1gph diesel at full load is a good thing.

 

[155mm]

We were out of power for 6 days, I used a 804a for all of our stuff here, never exceeded 50% capacity. My fuel consuption was 6-7 gallons a day, running 8 hours a day.

here is the link

http://www.steelsoldiers.com/showthread.php?167498-Wife-is-now-a-green-iron-believer

 

[Light in the Dark]

This is power backup, and not main power right? You should be able to use a 10kw in any sort of emergency situation, and you might be temporarily inconvenienced by having to either load manage, or turn off heat while you do laundry or something. Probably your best scenario for both cost and availability. Its about making it through with as little distruption as possible, right?

 

[eatont9999]

I may have to train the wife to use less if we are generator power. That or get two 803A's and synch them. I highly doubt the house has 3 phase power running to the main breaker.

A few other questions: What is the general consensus on high hour units? Say up to and over 6000 hours. I still lack the understanding of why 6000 hours is considered high and these engines have a 10,000 hour rebuild interval. Seems absurdly low. My only comparison is to that of automotive Diesel engines. Generally, 100,000 hours is roughly equal to 100,000 miles. I have cars that drive daily with over 4x that many miles on them. Please help me understand the logic here.

How many MEP-803A units can I fit into a full size pickup truck bed? I am thinking two. Anyone tried it?

 

[Dwnorton1]

You are not going to want to put more than one in bed of 1/2ton truck. They are heavy 1000+lbs if I remember right. I don't believe 2 would fit volume wise anyway. My silverado definitely knew it was back there, especially when braking. Also cannot Sync these in true sense of the word. Only sync temporarily while swapping in dual configuration with correct box.

 

[csheath]

Forget the sync and load management. Just go to Hardy Diesel Generators and order a 25KW Perkins. Don't forget to order the enclosure. About $13,250 should do it.

 

[98G]

I may have to train the wife to use less if we are generator power. That or get two 803A's and synch them. I highly doubt the house has 3 phase power running to the main breaker.

A few other questions: What is the general consensus on high hour units? Say up to and over 6000 hours. I still lack the understanding of why 6000 hours is considered high and these engines have a 10,000 hour rebuild interval. Seems absurdly low. My only comparison is to that of automotive Diesel engines. Generally, 100,000 hours is roughly equal to 100,000 miles. I have cars that drive daily with over 4x that many miles on them. Please help me understand the logic here.

How many MEP-803A units can I fit into a full size pickup truck bed? I am thinking two. Anyone tried it?

100 hours = around 3000 miles more or less.

What kind of welder? (I may be able to rule out an 802)

 

[jimbo913]

100,000 hours is not equal to 100,000 miles or you are driving really really slow.

I went with the 803, because my "smart" hot water heater has a startup sequence that fires the electric elements which requires 5500w.
Don't expect to operate much electric heat even with an 803. I heat with wood pellets (450w startup and 200w running). Just one of my heatpump backup strips is 10k watts and I have two heat pumps. The dual 2.5 ton A/C units with hard starts on both seem to work fine. Never had them start at the same time but I think the 803 could handle it. I use simple 1500w ceramic heaters to keep minimum load above 30% when higher power is not needed.

 

[jamawieb]

Just to give you some insight, my 2007 duramax has an hour meter on it and I've logged 5300 hours in 315,000 miles.

 

[eatont9999]

Got it, hours are not equal to miles.

It is a welder I do not own yet. It is on my list of tools and skills to acquire. I think the ability to weld 3/8" plate would be the most I need.

 

[98G]

Got it, hours are not equal to miles.

It is a welder I do not own yet. It is on my list of tools and skills to acquire. I think the ability to weld 3/8" plate would be the most I need.

Welding 3/8" plate open root with a stick welder is typically welded in 3 passes, using 1/8" rod at around 120amps. This is with the edges beveled.

Doing it in a single pass, without beveling the edges will take considerably more power (and a different skillset).

You may want to consider an 803 for the house backup genset , and a 3 phase monster for the shop.

 

[GREENMV]

When In doubt go bigger. !0Kw would be my choice while still watching the load by staggering your use. A/C, Hot Water Heater ETC.

 

[155mm]

I am guessing that a 15kw will be better suited. By his description it sounds like an older all electric home, and my guess is an older well motor with no soft start ability so the well by itself pegs a needle about 4k on a start. I think he would be gobbling up a 10k and running the chance of kicking the overloads. Only way to know is to get a clamp over amp gauge, and set it to peak hold, and just run the casa a couple days

 

[155mm]

I lnow he said he wanted a 80x, bit whats wrong with an oo4 with the single ph mod

 

[Guyfang]

It all goes back to post #4. And yeah, a clamp on Amp meter, set on max hold. Better to take the time to look/check/measure all this stuff before spending a dime on a generator.