# Fiber optic cable



## Church646 (Jul 17, 2013)

First time coming across this. Am I required to run fiber optic cable in conduit if its above the ceiling and non-plenum rated cable? There is no power involved so naturally I questioned myself.


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## MDShunk (Jan 7, 2007)

Is it a plenum ceiling? If so, you need to put it in pipe.

From a more practical standpoint, it's tough to get proper support of fiber runs above ceilings without at least cable tray. Might as well run pipe, in that case, if it's just one run.


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## mikeh32 (Feb 16, 2009)

You can run fiber free if its plenum rated....

But it is recommended to at least put it in innerduct, or use armored fiber. 


when it comes down to it, its cheaper


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## ttech (Jun 1, 2010)

Putting a riser rated optical cable in Plenum rated innerduct does not make it a plenum rated assembly You must use plenum rated cable in the duct.

I usually run just run a armored plenum rated fiber cable.


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## chewy (May 9, 2010)

We use catenary wires with velcro, one job we used preterminated LC-LC so essentially distributed patchleads across ceilings and down walls to through connectors offered up in MUTOs.


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## five.five-six (Apr 9, 2013)

I would put it in interduct or a cable tray if the budget permits. Over time, if you are using clips, velcro or zip ties to seismic wires, the optical cable will tend to bend and exceed the minimum bend radious and you will see it with a TDR, eventualy it may fail, though you have already been paid.


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## chewy (May 9, 2010)

This will not sag with the weight of a fibre on it and even if you tied velcro 6ft apart it still wouldnt drop itself in a manner that exceeded its bed radius.


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## five.five-six (Apr 9, 2013)

Right at the connection points it can. I've seen it hundreds of times. In on nonredundant systems it causes pretty major service outages

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## chewy (May 9, 2010)

five.five-six said:


> Right at the connection points it can. I've seen it hundreds of times. In on nonredundant systems it causes pretty major service outages
> 
> Sent from my SAMSUNG-SGH-I337 using Tapatalk


I have never seen it, if thats the case someone went full ****** installing it. 

If your splicing into a tray you should install a retention nut and bolt and tie the kevlar braid to it, if your running preterminated then you should have inadvertantly got over 270 degrees of bends just dressing it into the rack or cabinet and there will be no stress at the connector in the event someone pulls at it in its mid span across the ceiling. 

If you use the wire I have shown and velcro every 18" there will not be any issues.


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## five.five-six (Apr 9, 2013)

Have you ever run a TDR on it? If it's being used for workstations you may get away with it . But in applications where the fibers expected to perform to its rated specifications, the bottom cable in the picture you showed is not acceptable. I would a file deviation on it not accept it even if I was accepting fiber run outside of trays or Interduct

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## chewy (May 9, 2010)

five.five-six said:


> Have you ever run a TDR on it? If it's being used for workstations you may get away with it . But in applications where the fibers expected to perform to its rated specifications, the bottom table in the picture you showed is not acceptable. I would a file deviation on it not accept it even if I was accepting fiber run outside of trays or Interduct
> 
> Sent from my SAMSUNG-SGH-I337 using Tapatalk


Just a Fluke DTX1800 with fibre modules, tested within 6 months of installation though.


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## five.five-six (Apr 9, 2013)

The failures I see are 3-7 years after installation and with much less egregious minimum bend radius violations than that. You will see those bends on an OTDR clear as day. 

Your DTX1800 doesn't have an OTDR, at least mine doesn't. I use an old AXS-100 for OTDR. They are really cheep and if you get one, I guarantee that you won't be running fiber like that anymore. 


In your pic, is that single-mode or multi-mode?


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## chewy (May 9, 2010)

five.five-six said:


> The failures I see are 3-7 years after installation and with much less egregious minimum bend radius violations than that. You will see those bends on an OTDR clear as day.
> 
> Your DTX1800 doesn't have an OTDR, at least mine doesn't. I use an old AXS-100 for OTDR. They are really cheep and if you get one, I guarantee that you won't be running fiber like that anymore.
> 
> In your pic, is that single-mode or multi-mode?


I guess you would call it single mode as its pvc coated no.08 fencing wire. We put up wires like that and zip tie or velcro to them above drop ceilings.


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## five.five-six (Apr 9, 2013)

chewy said:


> I guess you would call it single mode as its pvc coated no.08 fencing wire. We put up wires like that and zip tie or velcro to them above drop ceilings.



What?

Is it 9 micron core or 62.5/50 micron core?


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## chewy (May 9, 2010)

five.five-six said:


> What?
> 
> Is it 9 micron core or 62.5/50 micron core?


I was being facetious, its pvc coated steel wire we use to zip tie or velcro our cables onto above drop ceilings.


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## chewy (May 9, 2010)

Heres some examples of what I mean.


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## five.five-six (Apr 9, 2013)

This is the correct way to run fiber your head notice how the minimum bend radius on the vertical this restricted


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## chewy (May 9, 2010)

five.five-six said:


> This is the correct way to run fiber your head notice how the minimum bend radius on the vertical this restricted


The correct way is whatever your code or standards in the respective juristiction allow.


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