Generator plan - what do you think?

[David Sims]

I power my hobby workshop with a 10hp gas 5,500 watt generator. It's time to move my 50 amp welder in. I currently feed a 200 amp panel 220v on a 30 (start up) amp circuit.

About 70% of the time lights, fan and an outlet or two for hand tools works fine. Using the air compressor requires lights off.

Option 1. A 10kw diesel 1800 rpm. Air cooled if they come that way. I'm told they use about a gallon of diesel an hour.

Option 2. Two 5kw diesel 1800 rpm air cooled. About 1/2 gallon an hour of fuel I think.

Power from the utility is not an option. A gasoline unit is not desirable.

Are the fuel consumption estimates correct? The shop runs about 30 hours a week.

What size unit(s) would you get?

Any years and manufacturers to stay away from?

What should I budget?

I'm in Middle Georgia and go to Warner Robins on a regular basis. I'm getting up to speed on looking, bidding, buying and hauling old green metal....but I'm also a little concerned about the long wait on my first deal.

Many thanks for your thoughts,

David

 

[Warthog]

No help with the GenSet sizing, but while you are deciding, bid and buy something small that requires an EUC to get the first one out of the way.

That way when you really find something, it won't take as long.

 

[Isaac-1]

Your fuel estimates are in the ballpark, at full load they will be a bit higher than your estimate, but not too much. If you are considering military surplus a 10 kw MEP-003A will likely do the job, just be aware they can be loud, if possible you would want to locate it away from your shop a bit (I m thinking at least 25 feet, but 75 would be better). I have a 3kw MEP-701a (MEP-016b in an ASK housing) just outside my shed and you can hardly hear youself think in the shed. Civilian units show up on GL, these are often larger commercial standby units, however occasionly you will see something in the 5-10 KW range (often mounted in light towers, etc), for sake of keeping it simple, Onan and Kohler make some good diesel units, stay away from everything else. At least around here the MEP-002's and MEP-003's have been selling on GL at what I consider insane prices for the last year or more, these can be good units, but remember with GL you are buying as-is, look at the photos carefully, expect to spend some money fixing them and don't go overboard on bidding. If looking at other sources, try to find an Onan DJC in the 10-12KW range (this has the same basic engine as the MEP-003)

Ike

 

[AceHigh]

Also it sounds like you need reliability, if you can get 2 or 3 of the same model so you have an instant parts source and perhaps almost no down time.

 

[David Sims]

Warthog and Ike, I appreciate it.

 

[David Sims]

AceHigh, That's right up my alley - the daily driver is an 82 300SD Mercedes and the 2 parts cars have paid for themselves a number of times.

 

[steelypip]

I would definitely go with the two 5KW gens. Not only do you have 100% spare parts availability for one unit, but the vast majority of the time, you probably are using 1-3 KW anyway. A 5KW unit makes 2 KW a lot more efficiently than a 10 KW unit does.

Also worth mentioning that the 70 CI Onan was sold as a 6 KW in the civilian marketplace, and that the MEP-002a is rated for a 300% surge rating for motor starting. You might well find that it'll pull loads that an "8 KW" commercial generator won't.

Oh, and for future reference, the percent load meters on the MEPs are calibrated for an 80% power factor. No derating for normal amounts of inductive load is required, but be careful not to overload the generator with resistive loads, per the -12.

 

[Isaac-1]

The big thing here is to get something that will run the welder, that means something that will accept the welder's sudden load all in one step.

Ike

 

[David Sims]

steelypip, I followed everything - and thanks except "but be careful not to overload the generator with resistive loads, per the -12." What is that?

 

[Isaac-1]

The -12 steelypip refers is the tech manual (the manual numbers tradiationaly end in -12 -34 -24 for operators/field manual, repair manual and parts manual)

Whole books could and probably have been written on the concept of power factor, in its simplest terms power factor refers to if the the peak amp draw happens before, at , or after the peak of the AC voltage wave form. This is represented as a number, when you have a purely resistive load like heating elements or incandesant light bulbs a PF of 1.0 occurs, most motors have a lagging power factor, typically a PF of .8 (although it can be much lower), and some equipment (magnetic ballast, etc.) have leading power factors.

Unlke most civilian generators which are rated at PF of .8 for 3 phase and PF of 1.0 for single phase these MEP units are rated at .8PF for both 1 and 3 phase conneciton.

Ike

 

[WARWAG]

A 5KW MEP 002A should be plenty of power since they are really 7 kw generators. From what ive been told and have read they are pretty bullet proof. You may need to fine tune her but after that it should give you thousands of hours of trouble free use. They have a 15,000 hour life before needed to be overhauled. Just change your oil and all of the filters according to the manuals. I just picked up 3 MEP 002a on trailers and they seem to be in excellent shape with LOW hours. Im in the process of changing all of the filters and flushing the tank. The fuel screen should be cleaned or inspected when you get your gen. These are a 2 stroke gen so they are louder. Best bet would be to put it in an insulated shed with some louvers that open on start up and route the exhaust outside. The exhaust will be super easy to route since it takes standard pipe fittings. While your at it find some solar panels and some batteries, power regulator and invertor (golf cart batteries work great) and set yourself up with a complete off the grid power system. Good luck and let us know what you get!

 

[David Sims]

WARWAG, Nice outfit; I just added a trailer to my needs list.

 

[Polycop]

Not to poop in the punch bowl but I'm kind of in the same boat as you and it doesn't look good. I've got a 003a and I'm looking to hook a welder to it. Knowing that 'buzz boxes' have major current inrush and related resistance losses it's kind of problematic. I spoke with both Miller and Lincoln and they both said that I would have less than satisfactory performance with a welder and my generator (lack of penetration is a big one). They both suggested an inverter welder (waaaay more efficient) or an engine driven welder.

Soooooo, I've been looking hard at the Everlast inverter welders (China imports) and I've also been checking ebay and craigslist for a used engine driven welder. I'm sure there are plenty of guys that weld with a 5kw Coleman Powermate but two major manufactures advise against it (and that's good enough for me).

Ask The Experts: Generators | Lincoln Electric

 

[Isaac-1]

I think I should point out here that the MEP-002 and MEP-003 are not your typical 5000-6000 watt generators, for one thing most consumer 5-6KW don't have real voltage regulators (some more so than others) which means they suffer from large amounts of voltage drop when hit with a large load. By comparison the MEP-002 and MEP-003 use a real electronic voltage regulation system, and a rather robust one at that, which is part of why they have such high motor starting capacity. Yes there will be a voltage dip, I am not going to tell you how big or exactly how long it would last only field testing would show that, but I will tell you that similar vintage commercial Onan generators are designed around a maximum instantaneous full load voltage dip of 20% and recovery to normal voltage in a sustained load in under 1 second. (In contrast some of the better newer permanent magnet regulated generators like the Kohler Fast Response series will react in about 1/10th the time)

Ike


p.s. if you start looking at Kohler generator, be warned that the marketing people there have started using the "fast response" term to describe some of their residential units without the permanent magnet regulation

 

[WARWAG]

Not to poop in the punch bowl but I'm kind of in the same boat as you and it doesn't look good. I've got a 003a and I'm looking to hook a welder to it. Knowing that 'buzz boxes' have major current inrush and related resistance losses it's kind of problematic. I spoke with both Miller and Lincoln and they both said that I would have less than satisfactory performance with a welder and my generator (lack of penetration is a big one). They both suggested an inverter welder (waaaay more efficient) or an engine driven welder.

Soooooo, I've been looking hard at the Everlast inverter welders (China imports) and I've also been checking ebay and craigslist for a used engine driven welder. I'm sure there are plenty of guys that weld with a 5kw Coleman Powermate but two major manufactures advise against it (and that's good enough for me).

Ask The Experts: Generators | Lincoln Electric

I understand what you are saying but he now uses a gas civy 5K gen and all he needs to do is turn off the lights. I MEP 002A is way under rated and will outperform that gas generator hands down. I would say go with a 10 MEP but if the 5KW MEP will work then he will have half the cost in fuel compared to the 10 MEP.

 

[WARWAG]

WARWAG, Nice outfit; I just added a trailer to my needs list.

Thanks. Something about being able to have a real generator with you anywhere you go is a good feeling! My plan is to have one available to run around town and keep my neighbors fridges cold if we ever have another major power outage.

 

[David Sims]

Polycop,

I appreciate the Lincoln Electric site. My situation appears the same. I guess the 15,000 watt generator he recommended assumed the welder would be run at full load, which I do not use since I sold the much welded early 1950s Cat cable blade D69U.

From what I understand a 10kw (or two 5kw) military spec gen should work with my 50 amp welder at almost full load.

David

 

[LuckyDog]

David,

I think a 10kW (003a) would run your welder with now problems. I don't think the 002a will do it too good though. AND you CAN NOT hook two 002a's together. You can't get the phases to synch.

The current ratings are:
003a 240V at 52 amps. Good to go with welder
002a 240V at 26 amps. Only about half of what ya need for the welder.

I am assuming the welder wants 50 amps at 240.
if it is a 50 amp 120 volt welder the 002 will do, but you'll need to turn off everything else in the shop.

What have you decided, if you have already decided?

 

[David Sims]

LuckyDog,

I bid on a couple of 5kw 002a's. I bid low and someone else got them; but all is well. At my price I would have enjoyed having one to run daily without the welder. I'm taking my time and looking for a 003a. I'll find one sooner or later. In the mean time I'm using steel rods with my gas welder.

Thanks for the info - especially that two 002a's dont synch to = one 003a.

David

 

[David Sims]

Project Update

In the last few months I bid on a bunch of 002 and 003's within 400 miles of home on GL and have not won one yet. Prices for these sets keep getting higher.

Last week while researching these units on this site I ran accross a thread that talked about C.H. Shook of Spartanburg S.C. (cell 864-425-3322) I bought a low hr (22) 2006 reman mep002. I would have guessed Mr. Shook was in his late 70's. At 89 years old he loaded the unit on my truck with his forklift with no problem.

He has other generators some 3kw and 003's and a couple of much larger generators. He also has a few very nice mil spec heat and ac units. His son Chuck has military trucks.

I connected the 002 to my shop this weekend and it pulls all of my shop equipment with no problem. I'm pleased with it. Note I'm still using my gas welder in the shop and when I have to have the stick welder I go to my old shop. Eventually I will get a deal on an 003. In the mean time I'm looking for an operators manual for the 002.