tryinghard said:
There's several different things being discussed here.
First, your question. . I don't doubt that a communication jacket bonded at both ends is a "continuous metalic path bonded to the grounding system in each building or structure involved". . What I'm saying is that I'm not willing to be the only inspector in northern Ohio that applies 250.32(B)(2) to communication wiring. . I haven't met an Ohio inspector yet that applies a communication jacket to 250.32(B)(2).
Another item discussed is multiple bonding of the current carrying grounded conductor instead of also having a separate fault current only equipment grounding conductor.
I believe an equipment ground always results in a better safer installation. . But I don't believe that all installations have the same cost vs benefit. . There are broad categories that have very different cost/benefit balances.
I would list the broad categories as:
1] inside
2] separate buildings/structures both on the same SDS
3] line side of the service but still load side of the SDS/utility transformer
4] line/utility/primary side of the SDS/utility transformer that supplies a service
As far as #4] goes, I don't see enough benefit to adding a fault current only conductor on utility runs that go from transformer to transformer. . Running it down the street would be extremely expensive and your current carrying grounded conductor potential to ground would increase significantly as you travel miles away from the single bonding point [which would undoubtedly be at the secondary of the supplying transformer at the substation.]
As far as #3] goes, running an equipment ground from the top of the pole or ground resting transformer that supplies the service to the building isn't a bad idea but it would add considerable expense to some large and long service laterals plus you would have to reach beyond the NEC to get it required. . That'll get into utility "turf" and they are going to be dead set against it.
As far as #2] goes, 250.32(B)(2) is gone for new installations and I don't disagree with that decision to get rid of it. . My only point was that it isn't as critical as requiring an equipment ground inside a building.
As far as #1] goes, we crossed that bridge a long time ago. . The only remnant is replacing existing stuff that never had an equipment ground.
So now that 250.32(B)(2) is gone, 250.32(B) looks alot like 406.3(D)(3). . The elimination of 250.32(B)(2) was a good change but the requirement of an equipment ground inside a building is more important and more of a safety issue than the building to building.
David
