250.24(a)(2)

P

Pinnie

Senior Member
Location
Ohio
Occupation
Commercial Electrician
“If the transformer supplying the service is located outside the building, at least one additional ground connection shall be made from the grounded service conductor to a grounding electrode, either at the transformer or elsewhere outside the building.”

Thoughts on this rule? Anyone remember to do this?
 
Pinnie said:
“If the transformer supplying the service is located outside the building, at least one additional ground connection shall be made from the grounded service conductor to a grounding electrode, either at the transformer or elsewhere outside the building.”

Thoughts on this rule? Anyone remember to do this?
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Not sure why they even have this, be pretty rare a POCO wouldn't have an electrode at the transformer or at least at the pole the transformer is attached to. Since this is 250.24 is titled "grounding of service supplied alternating current systems" the transformer itself is on utility side of the service point and NEC doesn't apply to it. If the transformer is not on the utility side of the service point NEC does apply but the service is now within the primary side conductors and the secondary conductors are feeder/feeder taps and no longer service conductors.
 
I've always wondered about this rule. Everybody, including me just ignores it it seems. POCO always installs an electrode on the transformer secondary, but I guess it's arguable if it counts for this rule since it's on the POCO side of the service point.
 
electrofelon said:
I've always wondered about this rule. Everybody, including me just ignores it it seems. POCO always installs an electrode on the transformer secondary, but I guess it's arguable if it counts for this rule since it's on the POCO side of the service point.
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I’m reading “a comprehensive guide to the NEC” and he just skips this rule. Probably for good reason.
 
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