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Fiber - Line Voltage same raceway

Chamuit

Grumpy Old Man
Location
Texas
Occupation
Electrician
Looked at a job today. They are looking at using existing Smurf that has a fiber line in already to also pull Romex from one elevation to the next. New one on me. I did not see any rating on the fiber. Other than wire fill, is there anything preventing this?
 

Barbqranch

Senior Member
Location
Arcata, CA
Occupation
Plant maintenance electrician Semi-retired
I expect it would be a lot safer for the fiber if you could run possibly THHN rather than Romex.
 

Chamuit

Grumpy Old Man
Location
Texas
Occupation
Electrician
It’s in sections so not continuous. Otherwise, that would be what I would do.
 

jap

Senior Member
Occupation
Electrician
My first questions would be.
We're talking Fiber and Smurf Tube, does the structure even allow Romex to be installed?
Second, I'm sure the existing fiber probably originates and ends at a place where it and electrical shouldn't be combined,
And,,,,
Lastly,,, why would anybody want to do that even if they could?

Jap>
 

Elect117

Senior Member
Location
California
Occupation
Engineer E.E. P.E.
Careful of the type of fiber insulation. See 770.11. You need to separate them by barrier depending on the fiber insulation type.

If the fiber is in the innerduct first you are very likely going to damage it if they are patch cables or not of a normal full insulation. Any 90s or 45s where the fiber rests underneath the pull will be sketch.

Lastly, listing requirements of 770.179. You will find a lot of non listed cable since telco companies don't always buy listed fiber cable.
 

jap

Senior Member
Occupation
Electrician
To save money. The same reason all kinds of sketchy ideas are put forth.

That romex has to go somewhere when it comes out of the smurf tube.
I'm curious of the overall plan of what it's going to be used for.

Jap>
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
That romex has to go somewhere when it comes out of the smurf tube.
I'm curious of the overall plan of what it's going to be used for.

Jap>
I don't care much why but it seems like a plan that has the potential to cause the fiber or Smurf tube to break and who knows how bad that problem is.
 

Elect117

Senior Member
Location
California
Occupation
Engineer E.E. P.E.
It is definitely weird.

This sounds like someone made a rough-in boo boo and now is trying to get a receptacle at the communication providers board so they can install the modem/router.
 

jap

Senior Member
Occupation
Electrician
It is definitely weird.

This sounds like someone made a rough-in boo boo and now is trying to get a receptacle at the communication providers board so they can install the modem/router.

That's what I'm picturing also.
That and foam insulation in the walls. :)

Jap>
 

Chamuit

Grumpy Old Man
Location
Texas
Occupation
Electrician
It’s for a generator.

Need to get from left side of house to right. Two stories to deal with. Smurf runs from garage to 1st floor attic, then there’s a second run to 2nd floor attic.

Not keen on using it since the fibre is already there.

I won’t be doing the work. Was just asked to look and offer an opinion.
 

jap

Senior Member
Occupation
Electrician
It’s for a generator.

Need to get from left side of house to right. Two stories to deal with. Smurf runs from garage to 1st floor attic, then there’s a second run to 2nd floor attic.

Not keen on using it since the fibre is already there.

I won’t be doing the work. Was just asked to look and offer an opinion.

Eeeeek!!!
Good luck. :)

Jap>
 

Elect117

Senior Member
Location
California
Occupation
Engineer E.E. P.E.
It’s for a generator.

Need to get from left side of house to right. Two stories to deal with. Smurf runs from garage to 1st floor attic, then there’s a second run to 2nd floor attic.

Not keen on using it since the fibre is already there.

I won’t be doing the work. Was just asked to look and offer an opinion.

Yaaaaa, really not a good choice. I would advise against it unless the fiber has like the outdoor insulation, that really thick stuff.
 

tom baker

First Chief Moderator & NEC Expert
Staff member
Location
Bremerton, Washington
Occupation
Master Electrician
I don’t see an issue. I have run fiber jumpers in wireway with 480 v conductors. Fiber jumpers are tough and can be almost tied in a knot. Multiconductor fiber is also tough. When you pull the NM in go slow with a person on each each end, with wire lube. Also a plastic fish tape is best
 

cabledawg

Member
Location
Boise, Idaho
Occupation
cable dude
Is there a crawl space you can use for the romex? Fiber can exist with power as long as its Non conductive. If maybe 1 fiber in smurf tube, Maybe disconnect the fiber, and tie a pull string/jet line to it and pull out and figure 8 it, then tie up romex and tape up the fiber to the romex and pull it through. Ive done that a few times at commercial locations only to get more fiber through for "Scheduled Maintenace" :) Hope this helps!
 
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