Question for Electrician

[roger55]

I am putting in a gas pump in front of my gas station themed workshop (for display only). I've already passed my electrical inspections for the build of my workshop.

The wiring for the gas pump lights comes from my workshop sub panel thru PVC conduit run underneath the concrete. (My workshop 100 amp sub panel has the ground and neutral separated and the ground comes from the house main panel.)

I am confused about the fact that my gas pump is bolted to the concrete (Isn't this a ground too?). Do I want to connect my green ground wire to the metal box? (I am also going to put in an outlet inside the pump and I would like it to be a GFCI for safety.)

I assume that I should hook up the ground wire. But the part that confuses me is the whole gas pump frame seems like it then is grounded in 2 places.

I hope I am being clear in my question.

Pic:

 

[Noisy Nova]

I am putting in a gas pump in front of my gas station themed workshop (for display only). I've already passed my electrical inspections for the build of my workshop.

The wiring for the gas pump lights comes from my workshop sub panel thru PVC conduit run underneath the concrete. (My workshop 100 amp sub panel has the ground and neutral separated and the ground comes from the house main panel.)

I am confused about the fact that my gas pump is bolted to the concrete (Isn't this a ground too?). Do I want to connect my green ground wire to the metal box? (I am also going to put in an outlet inside the pump and I would like it to be a GFCI for safety.)
Yes, connect the green wire to the junction box. Also be sure to ground the frame of the gas pump.
I assume that I should hook up the ground wire. But the part that confuses me is the whole gas pump frame seems like it then is grounded in 2 places.
The concrete base is not a good enough ground.
I hope I am being clear in my question.

Pic:

A real electrician will provide a better answer.

 

[LoneGunman]

Bond the metal box and then ground the receptacle, while the bolts may be acting as a ground it is not a ground as far as the NEC is concerned.

 

[Fast Orange]

LG,as usual,hit the nail on the head.Part of the reason for all grounds coming from 1 place is so that all exposed metal parts of electrical equipment are held at the same electrical potential-also known as bonding.

 

[roger55]

Thanks all of you for the answer.
I figured that was what to do but I wanted to make sure I wasn't doing anything wrong.

And Nova, a retired electrician is still a "real" electrician!
I am a retired Hydrologist as of last August.

Btw, here is a link to my Gas Station Workshop build thread in case you are interested:
http://www.garagejournal.com/forum/showthread.php?t=8044
I started this thread over 2 years ago when I was just thinking about what to build.

 

[tfi racing]

I agree as well,bond the box,receptacle and frame.That's an interesting piece of history,be sure to show us more pics and how it works(or was intended to) when you get it completed.

 

[Noisy Nova]

Thanks for the link to your garage build Roger. I hadn't seen that before now.
I guess I should start my own photo gallery, as I have a former gas station / variety store on the property.
So far I've been embarrassed to showcase it as it's not up to even the lowest standard.

 

[sberry]

Yes, the earth is not a substitute for a grounding conductor.

 

[roger55]

I agree as well,bond the box,receptacle and frame.That's an interesting piece of history,be sure to show us more pics and how it works(or was intended to) when you get it completed.

Sure. I finished it yesterday.

Here are before and after pics:

 

[Thedroid]

The green wire acts as the path back to the circuit breaker to trip it in case there is a ground fault. The earth in most cases will not allow enough current to go back to the breaker and trip it, and the outside of the equipment can be energized for a long time with no indication.

Pump looks real nice by the way.

 

[walrus]

Pump is cool, worked on many of them.