Why?

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hardworkingstiff

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Wilmington, NC
I was at a job site Saturday and watched the non-power company sub contractor installing pole lights at a new site. They slid the conduit over the wire (1" PVC) and glued it prior to installing it in the trench. I walked over and noticed the wire was just 2-conductor. I asked about bonding, and the Forman said they install a ground rod at the pole and lug the neutral and pole ground wire to the wire to the ground rod. It looked like they were coming out of the U/G transformer straight to the pole.

I know that utility distribution is not regulated by the NEC, but when "they" start running pole light circuits, why aren't they required to meet NEC standards?
 
Re: Why?

Were they bonding the neutral to the same lug as the head's EGC, and the ground rod? Or are these poles floating? :(

If there is no service, and these are directly off the transformer, then a correct option (even by the NEC) would be to bond the neutral to the pole itself. That should prevent shock in most scenarios. If the neutral opened upstream, there would be a danger of shock on all poles downstream of the open neutral, which makes it undesirable.

Where do they get UF without a ground? :confused:
 
Re: Why?

Originally posted by georgestolz:
If there is no service, and these are directly off the transformer, then a correct option (even by the NEC) would be to bond the neutral to the pole itself. That should prevent shock in most scenarios. If the neutral opened upstream, there would be a danger of shock on all poles downstream of the open neutral, which makes it undesirable.

Where do they get UF without a ground? :confused:
Click to expand...
It would be correct to install a ground rod at each pole, re-grounding the neutral at each pole?
 
Re: Why?

Hardworkingstiff,

The NEC's not really written for this, so there's nothing specific to point at.

For an analogy, though, consider a house with 14 detached garages. If there were a panel at each garage, but no EGC's pulled between each garage, then it would be configured the same way. Each garage would be required to have grounding electrodes installed, and since there's no EGC, each panel's grounding bar would be bonded to the neutral. (250.32(B)).

Now, for poles on the load side of a service, which the NEC does readily govern, the poles would be on a branch circuit. There would be an EGC run with that circuit. The poles would have their exposed metallic parts bonded to the EGC of the circuit. Since the poles are just structures with a single circuit in them, no grounding electrode would be required.

A grounding electrode can be installed for lightning protection, and bonded to the EGC.

In this setup, no one could be injured from an open neutral early in the circuit, because the exposed metallic parts are not bonded to the neutral in each pole. If a neutral opens in the circuit, human hands are not a potential path back to the source. :)
 
Re: Why?

Originally posted by georgestolz:
Where do they get UF without a ground?
Click to expand...
Probably from a cable manufacturer. ;) :p

Who said anything about UF? It's probably a specially made direct burial utility cable.
Utilities get all kinds of stuff that we can't buy. I'm not sure if they get it direct from the manufacturers or not, but with the mass quantities that they buy, they just might buy direct.
 
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