Grounding portable generators? Is it really necessary?

[football]

So if my 240v cord from my generator to the panel has a ground and that ground runs to the panel, I should switch my Genset from neutral bonded to floating neutral?

What happens it I don't?

Per code your panel in your home has bonded the white neutral wires with the ground wires. They are connected via a bonding bar in the main panel. Code only allows the neutral and ground wires to be bonded once, at the main service. If you have a sub panel, they cannot be bonded together at the sub panel. The generator acts as a sub panel (in essence)

Most modern portable generators have GFCI outlets. They bond the white wire to the ground wire on the back of the outlets or at the back of the generator power head. This is similar to your house in that the white and ground are connected. If you connect a generator to a house that has a bonded neutral , I believe I have read that there exist a small possibility of electrical shock, but I am not an electrician and dont understand the science behind why.

I did break the bond on my generators so that it is up to code.

I’d you ever use the generator in a portable manner (not hooked to the house) you can easily make a bonding plug and plug it into an outlet. You just connect a jumper wire from ground to white in a plug, and plug it into an outlet. Now the GFCI plugs will work as designed. When hooking back up to the house, remove the bonding plug.

Here is an article on the use of bonding plugs for use mostly on portable generators with floating neutrals …

RVelectricity: Do you always need to use a generator bonding plug?

Dear Readers, Nearly 10 years ago I designed and promoted the simple generator neutral-ground bonding plug. It allowed you to use an inverter generator to

www.rvtravel.com

 

[nomas]

They may want it grounded so that the ground-fault circuit interrupter (GFCI) will work.

GFCI does not use a GROUND to work .

 

[Schandyman]

The GFCI measures what goes in and what comes out and if there is a discrepancy greater than 5mA it trips.

Grounding the generator isn't going to make the GFCI work any better.

Not what I was getting at. There’s no path to ground if running as a stand alone generator. That’s why they’re WARNING to hookup a ground it’s to prevent the chassis of the generator from coming hot.

 

[brianl703]

Not what I was getting at. There’s no path to ground if running as a stand alone generator. That’s why they’re WARNING to hookup a ground it’s to prevent the chassis of the generator from coming hot.

If the generator's neutral is bonded to it's chassis, it won't become hot, whether or not it's connected to a ground rod.

And a ground rod won't conduct well enough to trip even a 15-amp breaker.

 

[Chris B.]

Thanks, gentlemen! This is over my head so I'll run it all by the electrician.

 

[Vern_in_IL]

I mean that's their use, but to cover their ars, they put that in there and we all know if you're working on a barn with no electric in it, you're not normally going to install a ground rod, but that's the safety you bargain with.

Most barns have lighting rods, pretty sure they go to ground rods!

 

[Schandyman]

What’s code on ground rods.. 2-8ft rods 4ft apart?

 

[ripcord]

I hope you have a forklift if you plan on moving it around a lot.

I was just at Harbor Freight the other day and those things are LARGE and look particularly heavy. Its similar in size to a gasoline powered Ranger or Bobcat welder.

 

[Pablo]

I hope you have a forklift if you plan on moving it around a lot.

I was just at Harbor Freight the other day and those things are LARGE and look particularly heavy. Its similar in size to a gasoline powered Ranger or Bobcat welder.

You are correct it is heavy. But quite manageable. Wheels baby!

 

[ka9mnx]

What’s code on ground rods.. 2-8ft rods 4ft apart?

Eight foot ground rods should be spaced 16 feet apart in most soils.

 

[Schandyman]

Eight foot ground rods should be spaced 16 feet apart in most soils.

I see that now.. length of rod x twice its length on spacing.

 

[Vern_in_IL]

...and what is the "proper" installation procedure for a ground rod? I've seen all types of methods and I read *somewhere* that using the water method to install a ground rod is not recommended, and that percussion installs are better.

 

[supton]

...and what is the "proper" installation procedure for a ground rod? I've seen all types of methods and I read *somewhere* that using the water method to install a ground rod is not recommended, and that percussion installs are better.

That is my reading too. I believe it is because the whole point is, contact with the dirt. Blasting a hole in and getting a loose fit means its not got great low resistance contact.