Why no splicing of ground rod conductors ?

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Ours wants the GEC ran through the meter, up the mast, and they crimp it with the neutral at the weatherhead on overhead services. (Even though the meterbase has a separate lug for the GEC)
 
Fred B said:
Was there a requirement that a continuous loop of wire from panel to each rod an back be made? We've had some inspectors insist on that.
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flashlight said:
Last service I did POCO wanted it that way
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That is a very prevalent method employed in upstate New York:. One continuous loop of wire through both ground rods and then back up to the enclosure (even if it's a single enclosure). NYSEG has a drawing in their spec book with that on it and it says something like "typical" so I don't read it as being actually required, but nonetheless most electricians do it that way here.
 
hillbilly1 said:
Splices are allowed, it’s just they are required to be in such a way that a bad connection is very unlikely. Split bolts, setscrew type connections can loosen over time. Cad welds (if done correctly) along with compression crimps have a low failure rate in this application.
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how would you know if they failed unless you happened to notice a loose GEC flopping in the breeze.
 
petersonra said:
how would you know if they failed unless you happened to notice a loose GEC flopping in the breeze.
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Doesn’t have to be flopping in the breeze, just a high resistance connection from a loose connection. That rule applies to all grounding electrode conductors, not just to a ground rod. That’s why code requires it to be non-reversible because you will not know it failed until it’s too late.
 
hillbilly1 said:
Doesn’t have to be flopping in the breeze, just a high resistance connection from a loose connection. That rule applies to all grounding electrode conductors, not just to a ground rod. That’s why code requires it to be non-reversible because you will not know it failed until it’s too late.
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what would constitute "too late"? since as a practical matter it does not really do much, even if it failed what would be the consequence? Unlike where an EGC failed there well could be a very serious consequence.
 
petersonra said:
what would constitute "too late"? since as a practical matter it does not really do much, even if it failed what would be the consequence? Unlike where an EGC failed there well could be a very serious consequence.
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Yeah it seems highly unlikely to me an electrical system could be truly floating. If the POCO has an MGN distribution system, the secondary neutral will be bonded to that. Even if its a delta, POCO will have a rod at the pole. Even if that is missing/stolen, a building is bound to have the grounded conductor earthed thru EGCs such as in the piping system or equipment fastened to masonry.
 
IMO contact with high voltage lines, a Mv line falling on a service drop, is about the only potentially valid reason I see for a premise GES. I know lightning is often cited, however I am skeptical a premise GES mitigates lightning at all.

Unfortunately grounding is so entrenched that is is nearly impossible for most people to think logically and scientifically about it so I doubt anything will ever change.
 
electrofelon said:
IMO contact with high voltage lines, a Mv line falling on a service drop, is about the only potentially valid reason I see for a premise GES. I know lightning is often cited, however I am skeptical a premise GES mitigates lightning at all.

Unfortunately grounding is so entrenched that is is nearly impossible for most people to think logically and scientifically about it so I doubt anything will ever change.
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how would a GEC provide any protection if a MV conductor happened to touch a service conductor?
 
petersonra said:
exactly how would that happen.
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A tree blows over in a storm and, say, a 7.2KV line falls on a service drop and makes contact with the messenger. Then messenger is probably grounded at the pole side too, but lets say its not and all we have is rods at the building which is 50 ohms. Even at say 50 ohms, that line should trip out. There is a chance it wont too, depending on a variety of factors. This is likely the only valid reason given in 250.4(A)(1).
 
electrofelon said:
A tree blows over in a storm and, say, a 7.2KV line falls on a service drop and makes contact with the messenger. Then messenger is probably grounded at the pole side too, but lets say its not and all we have is rods at the building which is 50 ohms. Even at say 50 ohms, that line should trip out. There is a chance it wont too, depending on a variety of factors. This is likely the only valid reason given in 250.4(A)(1).
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the messenger supported insulated conductors surround the bare messenger so how would the 7200 V line ever touch the messenger cable?
 
petersonra said:
the messenger supported insulated conductors surround the bare messenger so how would the 7200 V line ever touch the messenger cable?
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The two insulated wires are wrapped around the bare wire. Not surrounding it. Happens more often than not, although I’m not sure the rod has any effect.
 
petersonra said:
the messenger supported insulated conductors surround the bare messenger so how would the 7200 V line ever touch the messenger cable?
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POCO service triplex is not insulated, it’s covered. A few years ago, a 12.5 kv line fell across a service drop, blew the service panel (outside) off the wall
 
petersonra said:
So it didn't do any good to have the ground rod.
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I don't think we can conclude anything from such limited information. It is possible the ground rod helped clear that fault and it would have taken longer to clear or done more damage, who knows. All I am saying is it is plausible to come up with a scenario where ground rods help with contact with higher voltage lines.
 
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