System Grounding ok

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codequestion

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Attached is system grounding detail new service disconnect switch as shown for cell tower on building. See existing system grounding detail, single line diagram and elevation below. I am tying service disconnect switch to existing building system ground electrode. See both diagrams. Is it per NEC 2014 Article 250? Anything not per NEC 2014 Article 250?
 

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How are you feeding this new service? Is it a second service or are you bringing in another set of service entrance conductors? If so, this may change the size needed for your existing GEC and bonding jumpers.
 
as long as the existing conductor from the rod to the steel is #4 Cu or larger I think it is OK.

I am not sure the nomenclature used is correct though for the new wire coming from the new neutral bar. I think that is a GEC and not a bonding jumper.
 
jumper said:
Why go through the bother of that splice?

Because the drawing says so.

Take the new GEC to building steel and connect.
I agree this is code compliant.

250.68. You already have jumpers to rods and water pipe.
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Just because a different way is code compliant does not allow one to do something that is not in compliance with the contract documents.
 
jumper said:
I agree, I would never not do an EE/contract spec.

I thought OP was the designer. His third sentence seemed to imply this.
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I am third party reviewer for this one. I was wondering the same take it to steel. But drawings i got said take it to ground rods so I am wondering if taking to grouns rod splice their woulde be nec 2014 compliant.

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electrofelon said:
How are you feeding this new service? Is it a second service or are you bringing in another set of service entrance conductors? If so, this may change the size needed for your existing GEC and bonding jumpers.
Click to expand...
Just curious how so GEC size change if brining anothwr set of service conductors? Any article NEC 2014.

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codequestion said:
Just curious how so GEC size change if brining anothwr set of service conductors? Any article NEC 2014.

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See table 250.66 note 1. So say you have 250 MCM AL service entrance conductor. You have a #4 existing CU GEC (and bonding jumpers if applicable). If you add another set of service entrance conductors per one of the exceptions in 230.40, say the new set is 350 AL MCM, now your total area used to size the GEC (and bonding jumpers) is 600 MCM which requires a 1/0 Cu GEC. You can still use the GEC tap method in 250.60(D)(1) to size the tap for the 350 set, but the Common GEC would need to be sized for 600 effective area.

If you have a second SERVICE and not a second set of service entrance conductors, then I dont think 250.66 note 1 applies, so can a GEC or bonding jumper Serve BOTH services at the same time and only be sized for the largest service? I am not sure, maybe others will offer an opinion.
 
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