Minimum size conduit for optical fiber?

JimS

Senior Member
Have 270' run to detached garage and was thinking of doing CAT6 so started putting in 1" conduit figureing it would be plenty big for alarm system bus (Caddx), network and possibly pots.  Wondering if it will pass preterminated fiber.  Looking at this and can't find the overall dimensions of the end housing.  I can put it at the head of the pull so I it can take the full pipe diameter.
 
 
 
https://www.fs.com/products/74192.html
 
Not sure that is the best for this use but that's what I am currently looking at (having no experience with fiber).
 
I see each housing is 4.5 mm wide.  That's 0.177 inches.  Even allowing for double that for both connectors and another 0.177 for the clip that holds them together (which is likely smaller than that and I suppose could be taken off if it is not all one molded dual housing) still is only 0.531",  Well below the approx 1.04" ID of 1" conduit.  Yes, just one run plus a few other small wire cables as noted before.  Looks like I am fine with 1".  Was a bit worried as some say to put in 1.5" conduit to have room for end terminations.  I didn't see anything about wet rating so have asked the seller for that info.
 
Note the maximum tensile strength is only a few ounces of pull. Extremely thin glass is fragile.
 
These are jumpers made for inside equipment usage only and has no protective jacket.
 
JimS said:
Have 270' run to detached garage and was thinking of doing CAT6 so started putting in 1" conduit figureing it would be plenty big for alarm system bus (Caddx), network and possibly pots.  Wondering if it will pass preterminated fiber.  Looking at this and can't find the overall dimensions of the end housing.  I can put it at the head of the pull so I it can take the full pipe diameter.
 
 
 
https://www.fs.com/products/74192.html
 
Not sure that is the best for this use but that's what I am currently looking at (having no experience with fiber).
 
Consider getting on a chat with one of the sales reps, they can guide you based on your requirements. I did this when I was looking for plenum rated cables to run in my cold air return between floors of my house.
 
I've never pulled cable or fiber at a great distance like that, but I would have concerns about too long of a run to pull. Would probably need pull boxes along the way. Ask the rep.
 
The pull boxes would have to be huge. Bending fine Corning glass sharply creates cracking in the glass that can have you redoing the run a year later. The fractures don't always show up right away.

Get the proper fiber optic cable and install larger conduit. It is expensive.

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I was looking at some old threads and figured I would post what I did on this. I ended up using 4 strand (2 pair) version of this:
https://www.fs.com/products/70220.html
with pulling eyes. Pulled it into the 1" conduit with no issues being careful not to kink the fiber. I had install large radius bends at the transitions from vertical to the horizontal run in the ground. There is a 1" LB on one end where the conduit enters a building - I made an insert for it to ensure the radius on the fiber. It's working well.
 
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