# Fiber Optics



## Dennis Alwon (May 9, 2009)

Does anyone have any info on how far fiber optic can be safely pulled. I am told 300 lbs of force is the maximum but how do you figure that out? The pull is 600' with only 1" conduit but I am thinking we will need a few pull boxes. 

Any help?


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## backstay (Feb 3, 2011)

Dennis Alwon said:


> Does anyone have any info on how far fiber optic can be safely pulled. I am told 300 lbs of force is the maximum but how do you figure that out? The pull is 600' with only 1" conduit but I am thinking we will need a few pull boxes.
> 
> Any help?


 *Gardner Bender
**Wire and Cable Pulling Tension Meter Part # TM5, Might be too big.
*


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## LGLS (Nov 10, 2007)

If the cable has a central member, you can pull from that with whatever force is necessary. 600' and a bit of Poly Water you're good to go. What size/ type cable are you pulling?


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## Dennis Alwon (May 9, 2009)

IslandGuy said:


> If the cable has a central member, you can pull from that with whatever force is necessary. 600' and a bit of Poly Water you're good to go. What size/ type cable are you pulling?


I am not sure-- I think I am just installing the conduit but I want to make sure they are giving me good info. I don't want to hear them complain later and try and blame me.


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## backstay (Feb 3, 2011)

Dennis Alwon said:


> I am not sure-- I think I am just installing the conduit but I want to make sure they are giving me good info. I don't want to hear them complain later and try and blame me.


600 feet is a long way to pull anything. 1 in conduit is very small. Are hand hole ground boxes possible to loop into. For the $50 each, a few would go a long way to easing that pull. Or is this above ground? Then two pull boxes would be on my parts list.


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## chewy (May 9, 2010)

600ft in 1" conduit? Im sure it will become clear why 2" or 4" conduits are specified.


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## Dennis Alwon (May 9, 2009)

chewy said:


> 600ft in 1" conduit? Im sure it will become clear why 2" or 4" conduits are specified.


This is what they asked for and I thought that was small but apparently this is for a gate and is very small diameter


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## Dennis Alwon (May 9, 2009)

backstay said:


> 600 feet is a long way to pull anything. 1 in conduit is very small. Are hand hole ground boxes possible to loop into. For the $50 each, a few would go a long way to easing that pull. Or is this above ground? Then two pull boxes would be on my parts list.


One problem with handholes that was mention elsewhere and was my concern also is the problem with keeping the wire straight and not bending it too much as you pull it thru.

Price of the box is not an issue although I priced them and they are a lot more than $40 around here. The cover for an 8x11 box was $40.


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## pete87 (Oct 22, 2012)

Dennis Alwon said:


> I am not sure-- I think I am just installing the conduit but I want to make sure they are giving me good info. I don't want to hear them complain later and try and blame me.



Installing the conduit for 600' . I would install c - condulets and /or LB's .

Hell you might end up having to pull that yourself .




Pete


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## don_resqcapt19 (Jul 18, 2010)

pete87 said:


> Installing the conduit for 600' . I would install c - condulets and /or LB's .
> 
> Hell you might end up having to pull that yourself .
> 
> ...


Standard Cs and LBs are most likely not suitable for use with fiber.


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## LGLS (Nov 10, 2007)

Dennis Alwon said:


> I am not sure-- I think I am just installing the conduit but I want to make sure they are giving me good info. I don't want to hear them complain later and try and blame me.


Well, there's a different approach depending on what type and size cable. You can pull an 864 foc thousands of feet from the central member, or it could be they're installing a pippily 4 foc that's like wet spaghetti.


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## don_resqcapt19 (Jul 18, 2010)

How many bends in the 600'? Assuming an underground run and just "riser" 90s at each end, I don't think you would be anywhere near 300 pounds of pulling force. 

If there are too many bends I would look at a pull point, but I try to minimize pull points on fiber runs as much as possible. Every time you handle the fiber, like at a pull point, you increase the chances of damaging it. You have to make sure that you can get the fiber in and out of the pull point without bending it tighter than the minimum permitted bend radius.

For most fiber the radius of a standard 90 degree bend will not be too small for the fiber. 

You could do a pulling force calculation using a single aluminum conductor with about the same OD as the fiber to get an idea of what the pulling tension would be. Using an aluminum conductor in the pulling calculation should result in a pulling force higher than what would actually be required to pull the fiber as the fiber would weigh less than the aluminum conductor.


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## Dennis Alwon (May 9, 2009)

It seems like a pull box may not be necessary but I am not sure of the path. Definitely a 90 elbow at each end and I suspect a gradual bend down the driveway. I doubt it will be 360 degrees. Hopefully I will have more info by the end of Friday.


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## ponyboy (Nov 18, 2012)

I piped and pulled paralleled fiber runs at 1500' a few months ago in 1.5" pipe. The only thing the fiber guys asked me was to not change direction with a pull box, they liked a 90 and then a box. Other then that they said go nuts and do what you gotta do. It pulled like butter with 4 guys and some walkies











Sent from my iPad using Tapatalk


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## LoVolt134 (Dec 14, 2012)

What kind of fiber? 1" is plenty for most outdoor or indoor/outdoor jacketed fiber. Pull it in by the Kevlar and you will have no issues. Longest run I pulled in thru a 1" was 1200' no boxes in between. All strands tested fine.


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## NJSparky (May 21, 2014)

Strip it back and tie on to the aramid yarn (Kevlar) and you can pull all you want. the force will not be on the fiber itself but the kevlar, I never tie on to the strength member as I believe it's intention is for maintaining bend radius, not pulling, thats what the kevlar is for.


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## Dawizman (Mar 10, 2012)

If its a SJSA type fiber (likely if it's outdoors), then you will be perfectly fine. The cable is typically rated around 600lbs of installation force. I've pushed 500ft runs of the stuff by hand with a bit of polywater. 

We use a push-pull jetting machine to install fiber runs several kilometers long without ever exceeding 300lbs of pull force.


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## JW Splicer (Mar 15, 2014)

You'll probably be fine, just cut 15' off the end of it after the pull...


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