common grounding electrode conductor

[hhsting]

I have engineers arguing where is common grounding electrode conductor definition instead they just provide grounding electrodes conductors not common grounding electrode conductor.


Does NEC 2014 have definition of what common grounding electrode conductor is?

 

[tom baker]

When you looked what did you find?

 

[LarryFine]

One shared by more than one system, etc., and sized for the total service?

 

[electrofelon]

Presumably this is in regards to 250.64(D). I dont see that a definition is necessary. The Title of (D) and the instructions in (D)(1) seem to make it crystal clear.

 

[hhsting]

When you looked what did you find?

I wish it did it would avoid confusion they use it in a lot especially in NEC 2014 section 250.64(D)(1) from bus bar common grounding electrode conductor. I have situation where from bus bar outside there is individual grounding electrode tap from multiple service discos connected however other end of bus bar there are individual grounding electrode conductors sized per main incoming service conductor each going to different ground electrode of trough from which each service discos is connected.


I was wondering if the individual grounding electrode conductors since they are sized per main service conductors would be considered common grounding electrode and comply per NEC 2014 section 250.64(D)(1)?

 

[hhsting]

Presumably this is in regards to 250.64(D). I dont see that a definition is necessary. The Title of (D) and the instructions in (D)(1) seem to make it crystal clear.

I wish it did it would avoid confusion they use it in a lot especially in NEC 2014 section 250.64(D)(1) from bus bar common grounding electrode conductor. I have situation where from bus bar outside there is individual grounding electrode tap from multiple service discos connected however other end of bus bar there are individual grounding electrode conductors sized per main incoming service conductor each going to different ground electrode of trough from which each service discos is connected.


I was wondering if the individual grounding electrode conductors since they are sized per main service conductors would be considered common grounding electrode and comply per NEC 2014 section 250.64(D)(1)?[/QUOTE]

 

[infinity]

A common grounding electrode conductor is required to be a minimum of #3/0 which also happens to be the maximum size GEC required. If everything is #3/0 or larger then what is the issue?

 

[hhsting]

A common grounding electrode conductor is required to be a minimum of #3/0 which also happens to be the maximum size GEC required. If everything is #3/0 or larger then what is the issue?

There is more than one from bus bar that go to different electrodes

 

[augie47]

A common grounding electrode conductor is required to be a minimum of #3/0 which also happens to be the maximum size GEC required. If everything is #3/0 or larger then what is the issue?

I see the 3/0 minimum with common conductors for SDS in 250.30, I don't see the 3/0 minimum for services in 250.64. Am I overlooking it ?

 

[infinity]

I see the 3/0 minimum with common conductors for SDS in 250.30, I don't see the 3/0 minimum for services in 250.64. Am I overlooking it ?

You're correct, I was referencing the SDS requirements not for service switches.

 

[SSDriver]

Not sure if this helps.

 

[Ceedogg Electric]

One question. How many disconnects shall be permitted for that one common electrode.

 

[electrofelon]

One question. How many disconnects shall be permitted for that one common electrode.

Well normally we can have up to 6 disconnects grouped in one location. What would be interesting, and I don't have time to pick thru the wording, is if the "common and taps" method can be used with multiple disconnects from other 230.40 exceptions or multiple services.