Grounding Underground Cable in Conduit

[Elecengr2005]

To All -

I would like opinions on clarifications on NESC rule 96C. Background : 7200V, single phase system, # 1/0 TRXLPE cable in 2" conduit, 60 Miles underground installation, service drop {transformer} approximately every mile.

My question; Does NESC rule 96C apply to this situation with the requirements of (4) ground points every mile? Has anyone had similar situations / conditions?

Thanks

 

[wareagle]

Just for information what kind of installation is this. 60 miles is a long way.

 

[Elecengr2005]

Railway power for signal houses.

 

[alehman]

Will you have pull points spaced between the transformers?

 

[Elecengr2005]

Yes, there will be pulling points, but the terrain and the plowing of the cable will dictate where those are. So, in essense I'm not able to predict where those will be. With that, I'm looking for an interpretation to say how literal I need to follow the code.

Thank you,

 

[wareagle]

The interpertation is 4 grounds per mile as opposed to 1 ground every 1/4 mile. Thake a look at this

http://standards.ieee.org/nesc/NESCIR532.pdf

 

[Elecengr2005]

In essense, yes that is correct. They mention every 1/4 mile because it is much easier to justify 4 grounds in every "running-mile". The question I have really, I guess, is : Is my situation relevant to this rule. Are there any distinctions made in the NESC between single and three phase distribution?

Also has anyone seen situations of plowing in cable-in-conduit, and not had any pull points at which to ground it. I forsee this as being a situation we may encounter at areas.

Thanks.