Equipment Ground Conductor OUTSIDE the Conduit?

[clausb]

We have an application where wiring is specified on plans to have the equipment ground conductor routed in the conduit with the ungrounded conductors; owner requirement and engineer requirement. Contractor did not install the equipment ground conductor citing he is using the raceway as the equipment ground path. Fine, that is legal, but that is not what he was paid to install. Both owner and engineer want the equipment ground conductor installed.

Reviewing NEC 250, it does not appear that the equipment ground conductor has to be run in the raceway with the ungrounded conductors. 250.134(B) ends with "...or otherwise run with the circuit conductors." This leads me to believe that it is actually acceptable to run the equipment ground conductor outside of the raceway.

Don't get me wrong, I want the conductor in the raceway; however, I want to do my diligence to make sure all options are reviewed.

Any thoughts or comments?

 

[barbeer]

The EC needs to get a grip and install the EGC in the raceway as spec'd. Next time read plans better.

 

[charlie b]

250.134(B) is not a player in this discussion. It is saying to connect to the EGC, wherever it happens to be. The question of whether, or in which specific circumstances, the EGC is allowed outside the conduit it addressed in 300.3(B). I don't think the installation you are describing meets any of the allowable exceptions.

 

[dcspector]

Yes if the EGC is installed in the raceway with the circuit conductors then one could use 300.3(B)

 

[raider1]

Take a look at 300.3(B) also take a look at 300.3(B)(2). There are only a few exceptions where the EGC can be run on the outside of the raceway.

Chris

 

[raider1]

Whoops I see I was too slow.

Chris

 

[dcspector]

Are you looking at 250.102(E)...?

 

[dcspector]

Whoops I see I was too slow.

Chris

That will be a first.:grin:

 

[crossman gary]

First, if the plans say it should be in the conduit, then make them put it in the conduit.

As for the code, in my opinion, the EGC has to be in the conduit. This is based on 300.3(B). The permissions in 300.3(B)(2) do not apply.

250.134(B) does not technically apply as charlie b has mentioned. Plus, imo, the intent of the wording "or otherwise run with the circuit conductors" is not granting permission for the EGC to be outside the conduit. It is taking into consideration items such as busduct... which is not a raceway or a cable.

250.102(E) does not apply because we are talking EGC, not EBJ, although that could be argued.

Now of course, what about the argument of:

The conduit is the EGC and therefore the installation meets the code. If I choose to run an extra wire and connect it from the panel to the equipment, is there anything that says I can't? The feeder/circuit already has an EGC. Is there any reason that I can't run copper wire all over the building and connect stuff together?

Hypothetical for you inspectors:

An EC runs rigid metal conduit and pulls in a feeder with no wire-type EGC. The installation passes. Then the EC adds an external copper wire routed alongside the pipe and lugs it to the outside of the panel enclosure and the the equipment enclosure. Do you now give him a redtag? So then the EC removes the wire, he is good to go again?

None of the above negates the fact that it needs to be in the conduit by the job specs.

 

[winnie]

Devil's advocate here:
Since the raceway itself meets the NEC requirements as an EGC, then what is the restriction on an _additional_ conductor run on the outside of the raceway, and used to enhance the bonding of the various portions of the raceway.

An _intact_ metallic raceway is a better EGC (lower impedance ground fault path) than the wire EGC that would generally be run in that raceway. So if the customer selects, it is entirely reasonable to simply use the conduit.

IMHO a 'supplemental' EGC run on the outside of a metallic raceway offers all of the 'belt and suspenders' benefit of a wire EGC inside of the raceway, providing bonding across any breaks in the metallic raceway. Since this additional EGC is not required by the NEC, I see no requirement that it be inside the raceway.

The above begs the question: how large does this 'supplemental' EGC need to be in order to be installed without the mechanical protection of the raceway. Also, what fittings would one use to actually bond the EGC to the _outside_ of the raceway and boxes.

-Jon

 

[iwire]

The conduit is the EGC and therefore the installation meets the code. If I choose to run an extra wire and connect it from the panel to the equipment, is there anything that says I can't?

Since the raceway itself meets the NEC requirements as an EGC, then what is the restriction on an _additional_ conductor run on the outside of the raceway, and used to enhance the bonding of the various portions of the raceway.

Consider the following. If I have a metal conduit that meets all the requirement to be the EGC may I choose to install an additional 'under sized' EGC in the conduit?

The common response to that is no, if the conductor is intended to serve as an EGC, even an additional one, it must meet code.

 

[mkgrady]

We have an application where wiring is specified on plans to have the equipment ground conductor routed in the conduit with the ungrounded conductors;

If he runs the egc outside the conduit it doesn't meet the requirements you cite above.

If it is really written that way, you can require it that way. I would be interested to see exactly how the requirement is defined.

 

[crossman gary]

The common response to that is no, if the conductor is intended to serve as an EGC, even an additional one, it must meet code.

It's a fun question to kick around. What if I installed an under-sized wire on the outside of the conduit? The inspector says "red tag". I say "wait a minute, that ain't no EGC, that is a clothes line!"

The question Jon brings up is an interesting question and it isn't such a cut and dried "you can't do that."

 

[dcspector]

Consider the following. If I have a metal conduit that meets all the requirement to be the EGC may I choose to install an additional 'under sized' EGC in the conduit?

The common response to that is no, if the conductor is intended to serve as an EGC, even an additional one, it must meet code.

I agree with Bob. Additional egc needed or not once one chooses to install then all must meet 250.122 etc. xxxx sections.