How to wire a power panel right to my mep 803a generator

[rocky4by]

Im so confused, it can't be that hard. I have pulled up 50 posts on it. All I need is a panel and outlets right on my generator that will stay on the military trailer it sits on. Is there a simple photo that shows which lugs to connect for 220 and run to my panel, what size wire, what do I do about the ground? I have wired the past few homes we have owned. shop and all, i did have to ask some ? along the way but all went fairly easy. Almost every article I read on wiring this gen to a panel or home turns into a whirlwind of information. Any help would be much appreciated.

 

[DieselAddict]

Lugs 1 and 3 are your hots in 240/120v mode. N and G are labeled.

If you are using a panel that bonds the neutral and ground together, remove the bonding strap inside the terminal compartment.

 

[Scoobyshep]

Fast and easy version:

Generator L1 to L1 on your panel
Generator L3 to L2 on your panel
Generator L0 to Neutral on your panel
Ground the panel to the generator chassis

IMPORTANT: wherever you use you MUST provide a ground, most times a 10' rod (NEC says 8' must contact soil, that why they are 10'). somewhere in the system you must bond (connect) neutral to ground.

IIRC in single phase 240 the 803 is rated at 52 amps, in this case 6AWG is sufficient.


Hope this helps, if in doubt please ask

 

[rocky4by]

Thanks for the information. At our property the grounding rod is not an issue I can drive one in the ground, but I have welders and want it to be mobile, is there a way to run it without the grounding rod?

Fast and easy version:

Generator L1 to L1 on your panel
Generator L3 to L2 on your panel
Generator L0 to Neutral on your panel
Ground the panel to the generator chassis

IMPORTANT: wherever you use you MUST provide a ground, most times a 10' rod (NEC says 8' must contact soil, that why they are 10'). somewhere in the system you must bond (connect) neutral to ground.

IIRC in single phase 240 the 803 is rated at 52 amps, in this case 6AWG is sufficient.


Hope this helps, if in doubt please ask

 

[Scoobyshep]

Thanks for the information. At our property the grounding rod is not an issue I can drive one in the ground, but I have welders and want it to be mobile, is there a way to run it without the grounding rod?

You can, but it's not recommended. A wiring fault could energize the chassis and really ruin your day.

Most of the time it would be just fine, but you have to be lucky every time. It's that 1 time that you're unlucky that goes bad

 

[Light in the Dark]

Use a heavy set of jumper cables. Drive the rod, and hook up one side of the cables to the rod, and the same color (other side) to the grounding lug of the machine. Its better than nothing at all, and affords you versatility.

 

[rocky4by]

Im in NW AZ it's solid rock, even if I do somehow drive a rod on our 40 acres, I can't do that everywhere I might have to go out and weld. Maybe I'm needing a different generator to go mobil, but really prefer to use the 803A if I can. What's different in say a Honda generator, or habor freight? Or do they still need a ground rod too, we live off grid and use our Honda EB 3000 evey day.

 

[DieselAddict]

The most important thing is to get the generator electrically well bonded to the chassis of any vehicle it’s mounted to.

 

[Scoobyshep]

You are supposed to do it with any generator.

Are there common areas you'll be setting up? And out of curiosity what are you welding on?

 

[rocky4by]

You are supposed to do it with any generator.

Are there common areas you'll be setting up? And out of curiosity what are you welding on?

I do a good amount of trailer repair, soon I have to drive up to Oregon, i have 4 good size trailers up there that need brought back to life, new cross members, floors and goose neck repair. At the offroad races, it's 120 wall 4130 tubing , flat plat trailing arms, and you can imagine what else breaks on these cars. Not really a set known location except here at out home.

 

[Scoobyshep]

I do a good amount of trailer repair, soon I have to drive up to Oregon, i have 4 good size trailers up there that need brought back to life, new cross members, floors and goose neck repair. At the offroad races, it's 120 wall 4130 tubing , flat plat trailing arms, and you can imagine what else breaks on these cars. Not really a set known location except here at out home.

Oh I spent years in dirt track racing, so I know the score there. In the most common of setup areas (where you use it the most) drive a rod.

When you are out in the field doing a mobile repair, you are at the electrically safest position having a good ground, a cable to a steel building, fence, etc is better than nothing. Technically there is an exception for temporary portable generators in the NEC.

If you have to run ungrounded, (which is not recommended) don't make more contact with the trailer while it's running than you have to. 99.9% of the time you'll be just fine but it just takes that one time to ruin your day.

 

[pstansel74]

What do you do for generators wired to a house but also to test gear? A house would generally have the ground contained in the panel so you wouldn't need a ground, but the test gear you would have to have a ground for. Just unwire in the meantime or is there a different solution?

 

[Scoobyshep]

What do you do for generators wired to a house but also to test gear? A house would generally have the ground contained in the panel so you wouldn't need a ground, but the test gear you would have to have a ground for. Just unwire in the meantime or is there a different solution?

unless there is a switching action taken on the neutral the generator cannot be bonded ground to neutral. doing so will parallel the 2 conductors and allow the ground to become a current carrying conductor.

on older sets its a jumper between L0 and chassis newer sets have a bonding bar that can be removed.



so new sets move or install bonding bar in other older sets or where the bar isnt present, install a disconnect switch. One member here (i cant recall who) used a battery disconnect switch to toggle the bond

 

[pstansel74]

Thanks! What I figured but good to have confirmation.

 

[87cr250r]

The most important condition is that there is only one connection between ground and the neutral. It doesn't matter much where this connection occurs, in the panel or generator enclosure. If you're wiring to your house lift the bond in the generator. If your using as a portable only, leave the in place and use an unbounded distribution panel. If you're using it for both, use a bonded distribution panel but interlock it so the generator side panel is unbounded when connected to the house.

Remember, the ground neutral bond serves one purpose. It is a low resistance path back to neutral to cause a short circuit and trip a circuit breaker on magnetic trip in the event of a ground fault.

You can connect your generator and house grounds and that will tie your generator to the earthing rod.

 

[Guyfang]

You need to consult a professional in your area.

Why do you think the army gives you a ground rod and sledge hammer. The set needs to be grounded when you are in the back forty. Bonding the set to the truck or trailer is good, but tires do not a grounding make. You still need to ground the gen set.

 

[2Pbfeet]

For rocky areas, the MK-2551A/U might be easier to install, but it is not as simple as a ground rod, though purportedly a better signal ground.
I can recommend the army grounding manual, if you are interested.
CECOM TR-98-6 "Earth Grounding and Bonding Pamphlet"

MK-2551 A/U - RadioNerds

radionerds.com

Grounding is a sensitive and important topic in my opinion.

All the best,

2Pbfeet

 

[rocky4by]

For rocky areas, the MK-2551A/U might be easier to install, but it is not as simple as a ground rod, though purportedly a better signal ground.
I can recommend the army grounding manual, if you are interested.
CECOM TR-98-6 "Earth Grounding and Bonding Pamphlet"

View attachment 942660

MK-2551 A/U - RadioNerds

radionerds.com

Grounding is a sensitive and important topic in my opinion.

All the best,

2Pbfeet

Thank you. This is pretty cool. Im going to do some maintenance on my 803A and then start mounting and hooking up the main box. I'll post some photos so you guys can say, yes or no to what I'm doing.