Separate Ground Rod at Every Transformer

[Smart $]

However, nothing says you have to run a separate conductor to make this connection to the required GE. If the EGC is a conductor (as opposed to a raceway) and it is of the appropriate size all the way to the GE it has to be bonded to, there is no need to run another conductor. Just use the EGC.

I'll agree with that up to the point where the primary EGC is used in lieu of an available local electrode.

But that'll likely change once under the 2011 NEC cycle, where we will likely not be able to use an EGC as a GEC.

 

[petersonra]

I'll agree with that up to the point where the primary EGC is used in lieu of an available local electrode.

It's not being used "in lieu" of anything. it's being used to connect to the GE.

But that'll likely change once under the 2011 NEC cycle, where we will likely not be able to use an EGC as a GEC.

What possible beneficial purpurse could such a change make? Do the people that think these things up not realize how many bazillion SDS's there are out there? Especially small transformers under 10kVA?

 

[Smart $]

It's not being used "in lieu" of anything. it's being used to connect to the GE.

I understand that. But the requirement requires, essentially, the nearest of either the water supply or building steel electrodes when available, and preferably in the area of the SDS.

Say, for instance, there is structural steel somewhat near the SDS, but very difficult to route a GEC. I can see someone choosing to run a combo GEC/wire-type EGC with the primary CCC's "in lieu of" a solo EGC just because it is easier than running a GEC to the nearest structural steel... especially when planning on, having to run a wire-type EGC with the primary CCC's.

What possible beneficial purpurse could such a change make? Do the people that think these things up not realize how many bazillion SDS's there are out there? Especially small transformers under 10kVA?

I hope you're asking for opinions from any(all) forum participant(s), 'cause I see none. The only thing I can possibly think of is that some may consider a dubbed "EGC" as allowed to be undersized compared to a GEC. There was at least one countering comment that got shot down with little explanation.

 

[Smart $]

Here's the new 2011 section on the subject:

250.121 Use of Equipment Grounding Conductors. An
equipment grounding conductor shall not be used as a
grounding electrode conductor.

Does anyone else see the new section in direct conflict with this existing one:

250.54 Auxiliary Grounding Electrodes. One or more
grounding electrodes shall be permitted to be connected to
the equipment grounding conductors specified in 250.118
and shall not be required to comply with the electrode
bonding requirements of 250.50 or 250.53(C) or the resistance
requirements of 250.56, but the earth shall not be
used as an effective ground-fault current path as specified
in 250.4(A)(5) and 250.4(B)(4).