Conduit fill: does non-conductor count?

[Todd0x1]

When calculating conduit fill, does a non conductor count towards the fill? For example a pull rope left for later, or a fiber optic cable.

 

[Dennis Alwon]

I don't believe the code addresses that. It certainly wouldn't count for the number of ccc's, however I guess, if it is compliant, then you would have to figure the dimension of the rope.

Can you put fiber optic inside a conduit with conductors????

 

[texie]

It always amazes me that people want to leave a rope or string in an occupied raceway for later use. In most cases this will not be successful for later use and almost always damages existing conductors.

 

[Todd0x1]

Can you put fiber optic inside a conduit with conductors????

yes, 770.133

 

[Todd0x1]

It always amazes me that people want to leave a rope or string in an occupied raceway for later use. In most cases this will not be successful for later use and almost always damages existing conductors.

I agree. The worst is the IT guys that want some jet line pulled along with their Cat5. That stuff saws right through the cables.

 

[Dsg319]

It always amazes me that people want to leave a rope or string in an occupied raceway for later use. In most cases this will not be successful for later use and almost always damages existing conductors.

Work for a company that always wants and requires string (jetline) in any conduit that goes underground. Spare or used, doesn’t matter.
To make even more sense some conduit runs have boundary seals installed in them.

 

[Dennis Alwon]

@texie, you are an inspector so what would you require? A calculation based on the rope size or none at all?

 

[texie]

@texie, you are an inspector so what would you require? A calculation based on the rope size or none at all?

While I don't know of any code violation to install a rope or Jetline, I would try to discourage the practice. That said, if it is gonna be done I would require the fill calc to include the rope as the code requires all conductors to be counted as fill (not just CCCs) so it would seem reasonable that it should apply to anything occupying space. A piece of Jetline I would be inclined to ignore.
While I hate unnecessary code additions, maybe this is something that should be addressed in the code. I feel pretty strongly that practice of leaving rope or string in an occupied raceway should not be allowed due to the reasons I mentioned previously.

 

[Dsg319]

@texie, you are an inspector so what would you require? A calculation based on the rope size or none at all?

If we have to count a normally non-current carrying equipment grounding conductor in on fill calculations one would think, a rope Or any other object taking up space would have to be calculated in as well.

 

[petersonra]

If we have to count a normally non-current carrying equipment grounding conductor in on fill calculations one would think, a rope Or any other object taking up space would have to be calculated in as well.

that would be logic though. if the code does not actually require it, it is not required.

optical fibers have to be counted because chapter 9 table 1 says so.

(5) For conductors not included in Chapter 9, such as multiconductor
cables and optical fiber cables, the actual
dimensions shall be used.

I can't find anything anywhere in the code that thinks someone would leave a rope in a conduit. Maybe that is prohibited.

 

[Dennis Alwon]

I agree with both of you as I stated earlier. Just wanted to be sure the op got that info. It may be a good code proposal.

 

[Todd0x1]

that would be logic though. if the code does not actually require it, it is not required.

optical fibers have to be counted because chapter 9 table 1 says so.

(5) For conductors not included in Chapter 9, such as multiconductor
cables and optical fiber cables, the actual
dimensions shall be used.

I can't find anything anywhere in the code that thinks someone would leave a rope in a conduit. Maybe that is prohibited.

Thanks! that is exactly what I was looking for.

 

[GoldDigger]

Our here (at Stanford University forty years ago) there were underground duct banks joining all of the major campus buildings. The ducts are essentially straight runs from manhole to manhole to buildings. Some ducts that held communication wire were shared among cable, phone, data, etc. and each user of a shared duct was expected to leave a pull string.
Power ducts were another matter entirely.

 

[Carultch]

That said, if it is gonna be done I would require the fill calc to include the rope as the code requires all conductors to be counted as fill (not just CCCs) so it would seem reasonable that it should apply to anything occupying space. A piece of Jetline I would be inclined to ignore.

Is there an obscure definition that considers fiber optic lines to be "conductors". Because fiber optic lines are made out of glass, which is an insulator. And so would a pull string be an insulator.

 

[petersonra]

Is there an obscure definition that considers fiber optic lines to be "conductors". Because fiber optic lines are made out of glass, which is an insulator. And so would a pull string be an insulator.

It's a conductor because the code says it's a conductor.

 

[Todd0x1]

It's a conductor because the code says it's a conductor.

Its a conductor, just one that conducts photons as opposed to electrons....

 

[GeorgeB]

It's a conductor because the code says it's a conductor.

Although it is a conductor that doesn't (or isn't intended to conduct normally) conduct, there is often a steel strand for structural and location purposes.

 

[Todd0x1]

Although it is a conductor that doesn't (or isn't intended to conduct normally) conduct, there is often a steel strand for structural and location purposes.

Fiber installed in conduit with electrical conductors has to be non metallic