New Phone Line grounding

arnettda

Senior Member
A commercial customer is Bringing in a New Phone Line from Spectrum. They have a existing Line from a different provider that comes into a completely different area of the building. Both lines will be used.
Spectrum would Like a ground for their new Line. They say a ground rod would be okay. Can I drive a ground rod for this new Line at this seperate location? or am I required to run a bonding conductor back to the service. The other phone line has a dedicated ground that goes to it. I get confused reading articles 800.93 and 800.100
 
Using an isolated ground rod can cause more problems than it cures.

Yes, you should use the existing electrodes. Is building steel available?
 
Its good your thinking of it, and its good to pay attention to any old phone / cable drops or trunks becides lighting strikes they can be a parallel path to a multi grounded neutral (MGN).
I'd run a #10 green solid from the demarcation point back to any accessible point on the grounding electrode system (GES), that would be the minimum of the old Bell System Practices (BSP) if anyone remembers those LOL.
 
You can't really use an isolated grounding electrode. The code rule in 800.100 is to connect the the building grounding electrode system. While 800.100(B)(3) seems to permit an isolated grounding electrode, 800.100(D) requires a 6AWG bonding jumper from that electrode back to the building electrode system.
 
You can't really use an isolated grounding electrode. The code rule in 800.100 is to connect the the building grounding electrode system. While 800.100(B)(3) seems to permit an isolated grounding electrode, 800.100(D) requires a 6AWG bonding jumper from that electrode back to the building electrode system.
Yeah the phone company learned that the hard way decades ago, that diagram in post #5 is from a old phone company training manual, called the Bell Systems Practices.
Back in the day the phone company had a lot of pull in the code, they lobbied to get article 800 seperated from the rest of the code and 800 was just based on old Bell Systems Practices (BSP's).
 
Yeah the phone company learned that the hard way decades ago, that diagram in post #5 is from a old phone company training manual, called the Bell Systems Practices.
Back in the day the phone company had a lot of pull in the code, they lobbied to get article 800 seperated from the rest of the code and 800 was just based on old Bell Systems Practices (BSP's).
And I was told that the five foot ground rod permitted for the telephone ground was selected because that is what would fit in the old trailers the bell system used. Not sure if it is true.
 
Is Spectrum actually bringing in a POTS line on copper? Stranger thing have happened, but I'd expect it to be the product of a cable modem or fiber ONT (which doesn't need a ground).
Anything with a metallic path back to the utility pole traditional coax / unshielded twisted pair (UTP) should have a 'protector' grounded (or should I say bonded) with a wire back to the GES, the new fiber they install (if your lucky) does not have a metallic path so its exempt.
But yeah good point its probably a cable modem with a phone jack, a COAX protector at a DEMARC would be bonded, nothing then for the phone line per se like a UTP protector.
 
And I was told that the five foot ground rod permitted for the telephone ground was selected because that is what would fit in the old trailers the bell system used. Not sure if it is true.
Yes true. I was at a Mike Holt seminar and a person there used to work for Ma Bell. He explained they used a trailer and a five ft ground rod was the longest that would fit. There is a picture of him and the trailer in Mikes grounding book
And I was told that the five foot ground rod permitted for the telephone ground was selected because that is what would fit in the old trailers the bell system used. Not sure if it is true.
 
Is Spectrum actually bringing in a POTS line on copper? Stranger thing have happened, but I'd expect it to be the product of a cable modem or fiber ONT (which doesn't need a ground).
Not sure that Spectrum is doing FTTH like Verizon FiOS. So, it's probably just a coax cable drop that should be bonded to the GES at the point of entry. Don't listen to any cable guy who says "we can just pound a ground rod".

-Hal
 
Keep in mind the voltages that can be developed between unbonded electrodes from voltage gradients caused by nearby lightning strikes.
 
A commercial customer is Bringing in a New Phone Line from Spectrum. They have a existing Line from a different provider that comes into a completely different area of the building. Both lines will be used.
Spectrum would Like a ground for their new Line. They say a ground rod would be okay. Can I drive a ground rod for this new Line at this seperate location? or am I required to run a bonding conductor back to the service. The other phone line has a dedicated ground that goes to it. I get confused reading articles 800.93 and 800.100
In Clay county MO it is local code requirement for 6 grounding points to be at the bottom of every meter base exactly for this. Meter bases have required dedicated ground rod and so does the panel. I think it's overkill but....
 
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