Electrical Grounding with Ufer

[bfr57]

So, before I pose my question, I'll give the run-down of my shop's electrical system. The building is metal with the red iron braces, girts, purlins, etc. There is an approved Ufer ground installed that is grounding the 200 amp panel that comes directly from meter.

My question is grounding fixtures/outlets. Do I still have to ground them back to the panel with the "green" wire? My thinking is since the entire red iron structure is grounded through the Ufer (connected to the rebar in the concrete, which is attached to the J-bolts anchoring the verticals), why do I have to run the green ground wire from the metal outlets/fixtures that are screwed to the red iron back to the grounded panel?

 

[kd3pc]

read up on bonding vs grounding.

Your AHJ will define where and why and if you need to have the green wire all the way back to the panel, and under what installations/conditions.

It really varies by location and state.

 

[pattenp]

The two grounds are different. The ufer is a earth grounding system for things like lighting strikes. The green ground wire is an equipment ground. The requirements under the NEC are different for the two. The building's metal structure is not approved for use as an equipment ground conductor. Metal conduit can be used in place of a wire as an equipment ground if bonded properly.

 

[bfr57]

Thanks for the education. I'm really talking "bonding". Amazing how many professionals use the term "grounding" so loosely. We follow current NEC here.

 

[kd3pc]

Thanks for the education. I'm really talking "bonding". Amazing how many professionals use the term "grounding" so loosely. We follow current NEC here.

green wires go to the panel, on the ground bus, unless your metal conduit is electrically connected all the way back to the panel. Since it is a workshop and things get knocked around, I would pull a green to every outlet, screw them to the box and pigtail to the device. Then if someone breaks a coupling or pulls something out of the connector, your electrical is safe and still working.

NEC is the base line for installations, nothing wrong with doing things correctly the first time.

Sounds like your bonding is OK, so good to go there.