[scottieboy469]

I had a rather strange discussion with our electrical inspector today. We were planning on using the conduit as our grounding conductor. I would rather pull ground wire but we are trying to eliminate extra cost. He told me that we can use the conduit as a ground but where it enters any concentric knockout that has a bigger size available we could not use it as a ground. we would need to install a bonding bushing or install a ground wire. i knew this rule applied for service conduits but i was not awear it applied for branch circuits of 110v. Any input would be greatly appreciated.

Thanks

 

[Jlarson]

If you had circuits that were 250v or higher to ground then he'd be correct but not for 120v circuits.

 

[SteveBayshore]

Also circuits feeding into hazardous areas.

 

[tweak]

I have to agree with all the above. Look in 250.97. Could this be a state/local modifier?

 

[RIVETER]

I had a rather strange discussion with our electrical inspector today. We were planning on using the conduit as our grounding conductor. I would rather pull ground wire but we are trying to eliminate extra cost. He told me that we can use the conduit as a ground but where it enters any concentric knockout that has a bigger size available we could not use it as a ground. we would need to install a bonding bushing or install a ground wire. i knew this rule applied for service conduits but i was not awear it applied for branch circuits of 110v. Any input would be greatly appreciated.

Thanks

It is pretty important that when we are talking about "ground" that we understand what GROUND is... EARTH, and the solid connection to it for the purpose of dissipating weird voltages has nothing to do with the circuit operation. Bonding TO ground is important...as well,

 

[Jah Electric]

Always pull a ground! Like who hasn't ever seen a broken or pulled apart conduit. But like an unlicensed guy told me once when he was showing me how to wire wind turbines, this green one is called a ground, it doesn't really do anything but you still have to hook it up... And this white one is called a neutral, it's kind of like a ground, it doesn't really do anything either, but, you still have to hook it up... But youre an electrician, you probably already know that.... WTF!

 

[DIYer4Life]

Always pull a ground! Like who hasn't ever seen a broken or pulled apart conduit.

I've seen more broken splices than I have seen broken conduit runs.

If you think a conduit run is going to become broken, run it somewhere else or install provision to protect it.

Wasting expensive copper on a ground wire when the pipe is a much better conductor is just plain silly. I assume the only reason you are saying to do so is because it's someone else's money that you are wasting?

 

[scottieboy469]

Guys this is steel framed commercial building all the boxes and pipe are secured to the steel structure so say worst case a coupling pulls out or is loose your still securely fastened to the steel rafters. And the boxes have been ul listed with no additional bonding or grounding requirments yes I understand it wouldn't hurt but that is a crap load of extra money when there is absolutely no better ground than that emt

 

[Gregdrose]

I have had similar discussions with our foreman when the ground wire is going to increase the size of the conduit. When I tell them and show them in the code book that it is not required their response: That is poor workmanship or that is how we always do it.

I just shake my head. We are a union shop and in our line of work we are competing against non union shops and it is almost impossible to compete without taking any legal advantage available.

Install as per code and if anyone has an issue with it ask them to come in on the weekend to upgrade the installation at their own cost.