Fiber & power Conductors Outdoors

[yesterlectric]

I normally see designs that require separate conduits for fiber and power conductors and for planning my work I think this is best. However, in looking into whether for a modification I can share them, I find the 2020 code to be less clear than is used to be.

1. Firstly, for fiber cable in conduit that originate and terminate outdoors, I don't see where the code says anything about whether these can be shared with electric light and power conductors. Part II covers outside fibers entering buildings, not those that originate and terminate in equipment on a customer premises outside of a building. Part V, and 770.133 has some allowances, but Part V is intended for wiring inside of buildings. So it seems there's nothing saying we can or can't do this.

2. Secondly, it seems in 2020, they removed the definition of conductive optical cables, while adding an allowance in 770.133 for conductive optical fiber cables with an overall sheath to be shared in the same raceway as power conductors. What happened to the definition? I understand (I think) the motivation for the rule but the removal of the definition seems not to help.

 

[cabledawg]

If you're running OSP(Outside Plant) and its Conductive, use a separate pathway from power, never chance taking voltage INTO a building, whether commercial or residential! Massive liability if someone dies in Comm room/Mpoe because there's 5K volts sitting on something and that individual brushes up against it! It will ruin their day forever! Non conductive fiber can be ran with power all day long. Came across that very scenario awhile ago on a military base in Cali. The crew pulled in a 600 pair copper with the messenger wire still attached sitting inside the Dmarc. I made them pull it out to the first vault and remove the messenger wire(They were nice and happy). I think we used a split bolt in the vault with the appropriate size ground wire and went to building steel or the busbar. Hope this helps, Merry Christmas and Happy New years everyone.

 

[yesterlectric]

If you're running OSP(Outside Plant) and its Conductive, use a separate pathway from power, never chance taking voltage INTO a building, whether commercial or residential! Massive liability if someone dies in Comm room/Mpoe because there's 5K volts sitting on something and that individual brushes up against it! It will ruin their day forever! Non conductive fiber can be ran with power all day long. Came across that very scenario awhile ago on a military base in Cali. The crew pulled in a 600 pair copper with the messenger wire still attached sitting inside the Dmarc. I made them pull it out to the first vault and remove the messenger wire(They were nice and happy). I think we used a split bolt in the vault with the appropriate size ground wire and went to building steel or the busbar. Hope this helps, Merry Christmas and Happy New years everyone.

Yes but this is no explanation of the code rules.

 

[cabledawg]

Not sure there is any real concrete code in the books yet, that Im aware of. the only reference would be 770.133 in Mikes Book, Limited energy and communications. But that just tells you about running fiber whether conductive or Nonconductive with Class 1,2,3 circuits all in the same raceway. As to your 1st original question, if the fiber terminates outside the building, then I don't see any reason why you couldn't ground the fiber outside or take it to the nearest ground. Or if none, make your own ground.