Location of Telephone Primary Protection?

[theskipper]

Working on a house where the telephone company installed the NIU with integrated primary protector on the streetside elec. service pedestal. Telephone service will then run through dedicated underground PVC conduit to house about 75 feet away. Shielded cable with shield grounded at both ends will be used.

Question for this august group is whether an additional primary protector is required at the point of entrace to the house. 800.90 (B) says the primary protector on the circuit must be in, on, or adjacent to the building or structure served. Is the pedestal considered to be that structure? If so, the subsequent run to the house is an interbuilding circuit that per 800.90 (A) doesn't require a primary at each end if less than 140' in length run underground using shielded cable. Or is the house itself the structure, which would require a much closer protector?

Thanks in advance
Skip

 

[tom baker]

Art 800 says if the NIU is more than 20ft from the electical service, a 6 AWG copper bond is required between the NIU and building electrical grounding system, for one and two family dwellings only.
This issue is complicated as the NIU is by the teleco and they are not subject to the NEC, however the EC is the one to get the violation.
your objective is to create a single point ground. Ideally the NIU is immediatly adjacent to the electrical grounding system and bonded to it.

 

[theskipper]

Tom, thanks for the reply.

You're right that Art. 800 lays out the grounding requiements pretty clearly... basically, if you cannot tie the primary protector and cable sheath to an acceptable point on the structure's grounding system within 20 feet, then you must drive a supplemental grounding rod and bond that to the structure's grounding system (i.e. with 6 AWG or larger copper).

I think my root question is what constitutes a structure... is the pedestal where the NIU is currently located (and currently grounded on its own rod, there is no other ground on the pedestal) its own structure, which given the other conditions means I don't need an additional primary protector on the interbuilding run to the house, or is the whole service drop from the pole to the house considered one circuit, in which case I DO need a primary on the house itself, grounded as outlined above?

Any further thoughts much appreciated.. though increasingly I think the bottom line is that an additional primary is relatively cheap insurance and worth doing regardless of code.

Thanks
Skip

 

[hbiss]

800.30 (B). The primary protector shall be located in, on, or immediately adjacent to the structure or building served and as close as practicable to the point of entrance.

I think that is pretty clear. I don't know why you are mincing words here, a pedestal or pole, unless it is immediately adjacent to the structure or building served won't fly.

Who is providing and connecting the buried service wire? If it is the TELCO have them provide the additional protector also.

-Hal

 

[Pierre C Belarge]

From Hal
"800.30 (B). The primary protector shall be located in, on, or immediately adjacent to the structure or building served and as close as practicable to the point of entrance. "

The underground protection here is really for lightning. The protection is not to protect the cable but the house and attached equipment in the house. I would agree with this "august group" and say install the protection at the POE.


I like that phrase - August: Marked by majestic dignity or grandeur.

 

[theskipper]

Thanks all, points taken. Not trying to be stupid, this part of a huge project has just fallen somewhere between the telco (who put the NIU on the pedestal because the LV conduit is interrupted there en route from the street to the house and don't care what happens downstream of it), the EC who doesn't want to mess with phone wiring, etc. Me, I just want it done both code compliant AND well...

Rest assured that a proper UL-listed protector will be installed at the point of entry in compliance with all applicable provisions of Art. 800.

This is a hugely useful forum, thanks to all who contribute their expertise.

Skip

 

[dlhoule]

I like that phrase - August: Marked by majestic dignity or grandeur.

And here all this time I didn't think August came about until next month! :smile:

 

[hbiss]

I like that phrase - August: Marked by majestic dignity or grandeur.

That's probably why I was born in August.

-Hal