mep 003a new owner

[flyfishrelease]

Should the gen speed, once set to get 60 hz (120 v 1phase) at about 500 watt load, drift down about 0.5 hz when loaded to 1700 watts? Will this amount of shift damage anything in the house if gen. is connected to house? I understand that computers don't like shifting away from 60 hz. What shift in frequency would one expect if loaded to 10 kw from 1kw or what shift vs load is normal?


Charlie

mep 003A

 

[Carl_in_NH]

It will be just fine for your home. You will see some drift from low or no load to full load, but nothing that would cause damage to anything with a properly working genset.

There's a spec on this in the TM which I think was +/- 2 Hz - but I'm going from memory and am therefore likely inaccurate. Time to scan through the TM again...

 

[Ken_86gt]

Computers don't care much at all about frequency- I would bet your computer will run just fine on 50HZ if that is what you had. The power supplies just rectify the AC to DC, no frequency at all.

 

[Isaac-1]

Mechanically governed generators should generally be set to about 62 Hz at no load, so that they will droop to 60 Hz at full load. A well calibrated mechanical governor can do a little better than that, so depending on luck and skill you may find your able to achieve full load droop to 60 Hz from a starting point a little under 62 Hz, say 61.5 Hz. Better performance than this requires the use of an electronic governor. As to computers and other home appliances, most should run without any problem on generator power from your MEP generator, potential issues may be found in some cheap electronic appliances like cheaper microwave ovens (a common problem item for RV owners when running on generator power) or larger SCR based battery chargers sometimes found in inverter/chargers for off grid cabins (inductive loads from large SCR's can cause electronic voltage regulators all sorts of problems, adding large filter capacitors sometimes helps, also if you have a computer battery backup or UPS they may complain about voltage or frequency tolerance, the better models offer some form of adjustment (knob or switches) to widen the acceptable range.

Ike

 

[flyfishrelease]

Thanks for the info. Ah.... that mighty tm, how does one get along without it??

I'm about ready to hook gen. to house , the interlock system seems like the way.
One source says if you buy the interlock device from the panel manufacturer it's approved, in my case the panel is square D. Will check at Lowes for an interlock.
Read threads last night on grounding the gen. frame, at first I was confused but after reading a couple of times I understand that the house ground is major and gen. frame should be grounded via house ground to eliminate double grounding.

Charlie

mep 003a

 

[Isaac-1]

Check with your local electrical inspector to see if they will accept an interlock kit, they are not allowed in some places even though they are accepted by the current NEC code.

Ike

p.s. I doubt you will find one at Lowes, likely you will have to order through an electrical parts house, or online. Depending on the model you need they seem to start around $5 on ebay when I just searched on "square d interlock"

 

[glcaines]

I found an NOS Square D manual transfer switch on Ebay for a really cheap price and it works great. I wired the 003A to the transfer switch via a 100 amp pin and sleeve connector. I wired everything myself and had no problem with the inspector.

 

[flyfishrelease]

mep 003A house hookup amp rating

House is all electric except for oil heat. What size amp breakers and wiring should be used when connecting the mep 003A to house for emergency power outages. Will want to run furnace, refrigerators, maybe one burner on electric range, lights and tv. Electrical equipment salesman said 50 amp was overkill for most residential needs during an outage and 30 amp should work fine. I realize that amperage rating required is dependent on loading but in general will 30 amp do the job without nuisance trips?

Charlie

mep 003A

 

[Isaac-1]

Your question is a bit open ended, but if your asking what size breaker you should feed into your panel when using a MEP-003a and an interlock kit, you want it to be equal or greater than the rated output of the generator, in this case the MEP-003a in 120/240V single phase mode is 52 amps, you therefore want to size your wiring and breakers large enough for this, likely the next size larger breaker you will find is 60 amps (which is the smallest I would go considering that is a military conservative 52 amp rating). Having said that it sounds like the salesman does not have a clue. Also keep in mind this breaker is doing very little in this application, mostly acting as a switch since there is no wire for it to protect as it is being back fed from the generator, and the generator's output breaker should protect the wiring to the panel (assuming the wiring is sized right, this is of course theory, reality is the generator would likely overload before tripping the protective line breaker).

Ike

p.s. wiring size will depend on multiple factors, including length of run, type of wire, if it is in conduit, etc.

 

[glcaines]

I have 400-amp service in my house. My MEP003A is mounted on a M116A2 trailer and I wanted to keep the genset portable. I keep the trailer in my garage, and simply raise the garage door when I need to run it. I used a 400-amp 4-pole Square D manual transfer switch. The feed from the genset is directed to both 200-amp panels, still using the same 200-amp breakers that feed the panels. This way, I can feed the entire house. I ran 2/0 entry cable in conduit underground from the transfer switch over 100' to a 100-amp pin and sleeve receptable suitable for outdoor use which is mounted just outside my garage. I ran 25' of 2 AWG copper SO cable from the genset to a 100-amp pin and sleeve plug. The whole setup is manual, which is what I wanted. When I need the genset, I simply plug the pin and sleeve plug in the receptacle, and fire up the 003A. Once the genset output is stabilized, I throw the transfer switch. However, I do try to shut off all high-amp appliances first so that the load is not added all at once. I have a fairly large house that is 100% electric and a geothermal heat pump. The 003A will run the entire house, including both ovens and the HVAC on with most lights. The highest load I've seen on the meter is 75%. When not in use, I coil up the SO cable on the trailer and I can pull it to anywhere I need power on the property or elsewhere. When the house is powered by the genset, you would never know it as TVs, computers, etc. all run fine - - you only have the noise to remind you where the power is coming from. These are amazing generators. I also sometimes utilize the 3-phase output to run some 3-phase power tools I've got. I keep the fuel tank full to minimize corrosion of the tank. Once per year, I drain the tank and refill with fresh diesel, the drained fuel going into my JD tractors. I don't store fuel since I have two JD diesel tractors and two deuces that I always keep full of fuel. If the genset needs to run longer than one tankful will support, I simply use the auxilliary fuel input on the 003A to pull fuel from a tractor or truck tank. This way, I never have any fuel that has aged beyond usefulness.

 

[flyfishrelease]

mep 003A house hookup amp rating

Thanks to Ike and Gary on comments. Ike, you mentioned that amp rating for 10kw gen is 52 amp. How do you arrive at 52 amp, say for 120v. Iv'e looked thru tm but didn't find what amp the gen. breakers are rated for. Also read the thread about trying to get a 10hp motor started, seems like it's not clear what amps the gen. breakers are good for.

Charlie

mep 003A

 

[Isaac-1]

The 52 amps at 120/240V single phase came from the WIKI MEP 002A and 003A - Steel Soldiers::Military Vehicles Supersite (this also happens to be double the output of the MEP-002a which makes sense) I am not sure on the breaker ( I own a MEP-002a, and a couple of MEP-016's, etc ), but I am fairly sure I have seen discussions here about the MEP-003a having an adjustable trip breaker and there being instructions on setting it in the TM. Hopefully someone else can help on this one.

 

[derf]

52 Amps at 240V is 12,480 Watts.

52 X 240 = 12,480.

Why 52 and not 50? Who knows?

 

[jrcampbe]

52 Amps at 240V is 12,480 Watts.

52 X 240 = 12,480.

Why 52 and not 50? Who knows?

The generator has an 80% power factor. Power factor is the ratio of the "apparent power" to the "useful power". In order for have 10kw available to the load (useful power), the generator actually needs to generate more "apparent power".

Your generator, at 52 amps X 240 Volts generates 12,480 watts of apparent power.

Now, considering power factor:

12,480 watts x 0.8 PF = 9,984 watts. Call it 10,000 watts or 10KW. So you have 10KW of "useful power".

That's why it's 52 amps.

 

[Ken_86gt]

I would just look at the data plate. It clearly states 52 amps at 240v. When I size wire for a generator I always use nameplate data. Keep it simple.

 

[flyfishrelease]

Ok for 240v but what about 120v?

Charlie

mep 003A

 

[Ken_86gt]

Did you look at the dataplate? 120 only is 104 amps. If you are connecting to your house you need the 120/240 witch is 52 amps per line, you get two hot wires in this config. 120 only config gives only one hot wire.

 

[flyfishrelease]

If one would connect a load between L1 an L0 that could draw 105 amps what would be the max amps in the line? Agree nameplate states generator puts out 104/52 amps for 120/240 volt 1 phase but what amps are the gen. circuit breakers good for?

Charlie
mep 003A

 

[Ken_86gt]

According to the connection chart in the TM, if you connect a load between L1 an L0 you will get 0 amps. The 120V connection is to be made between L3 and L1 (or L0). You should be able to get 104 amps on each line. So I would say that the breaker on L3 would have to be rated ~104A, L1 ~104A, and L2 ~52A just to make the rated outputs in the various configurations. Now I suppose that the CB has multiple settings (like voltage taps on a transformer) that could be set when the configuration is changed- someone would had to do further investigation.

 

[Isaac-1]

I think there is a variable trip point on the MEP-003a output breaker, should be in the TM along with how to set for the various output modes.

Ike