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Beginner Fiber Questions

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grundy

Technical User
Apr 12, 2003
146
US
We need to add fiber to two rooms that are close to the IDF. I was just going to get pre-terminated cords and run to a passthru at the jack.

1. Should conduit be run through innerduct in the wall or EMT conduit? If not should I get fiber cabling with a thicker jacket?

2. Any issue running the fiber on J hooks with all the other voice and data? Should it be in innerduct? Separate Hook;?

Thanks!
 
Most if not all quality fiber installs I have seen in ceilings were done with duct. The duct serves as protection for the fiber. I have seen the duct run side by side with network cable, but again in duct. All my fiber runs go to closets or switch rooms, so the duct comes down from the ceiling, and strapped to ladder racks, to its termination point. I can't say that I have seen fiber run in walls, or at least yet.
 
If you are going to use Pre-term you should run it in duct or conduit always
 
Standard EMT conduit will work fine?
 
I'd use what they call "smurf tube" It's usually 1 inch dia. and comes in white, orange and (of course) blue.

The answer is "42"
 
Don't know about anywhere else but in Australia White conduit is for Comms, Orange is for UG power, Blue is for Water & Yellow for Gas
 
If you are going to use Pre-term you should run it in duct or conduit always

Perhaps we are not clear on the definition of preterminated, but neither the type of termination nor the time of termination should dictate whether the fiber is enclosed in a raceway.

You can order duplex 3mm fiber jumpers preterminated, you can also order tight buffer distribution fiber (900um jacket) preterminated and you can order breakout (3mm jackets within a cable jacket) fiber preterminated. If you are thinking about 3mm duplex patch cables, personally, i don't believe those have any place but in the closet between equipment and panel. If you are leaving the closet and going some where, you should be using fiber designed for that purpose.

The breakout fiber is plenty robust to be run by itself or with the copper cabling. However, the best solution is to protect it in a raceway. You just never know when someone will pull somethin across and burn it or damaage it in some other way. Placing it inside innerduct is affordable protection.

Again a personal preference, but smurf tube (ENT conduit) is so named for it's blue smurf color. It is a rated product for electrical applications, and as such it may show up carrying AC power through out your facility. The Riser-guard product from Carlon is listed for optical fiber/telecom applications and definately won't be confused with building power. It is available from 3/4 to 2" sizes and i'd guess you'll have no trouble find 1" available which is a good general size to have around.


If you have a plenum air handling space to run through, you should consider the Riser Guard product from Carlon for those area.

Always more than one way to accomplish things, depends on the need and the budget.

good luck!

Daron J. Wilson, RCDD
Solving 'Real World' problems
 
I have been working fiber for about 20 years now and if you are just running fiber on one floor (Horizontal Cabling) just as Cat-3, Cat-5 / Cat-5e or Cat-6 you don’t need conduit,
Just buy Plenum Fiber. If it’s less that 50 feet you can get 75’ plenum Patch cords, the only thing is if you have to penetrate a fire wall you will need a conduit of some type that will pass our local building codes. I always order orange Jacketing on all my fiber.
Also be sure as to what type of fiber you will need (Multimode or Single-Mode) and what types of connectors on each end.
 
Actually, the reason for putting the fiber in a raceway in a horizontal run is generally protection from physical damage. Plenum rated fiber will not provide any greater protection from physical damage than PVC jacketed fiber. Furthermore, there is no reason to spend the extra money for plenum rated fiber unless you are actually running it in a plenum space. Most horizontal cabling spaces are not actually air plenums, check before you buy.

If your reason for considering raceway IS because it is a plenum space, you can of course purchase plenum rated fiber and install it without a raceway. Generally we prefer to spend the extra money and install innerduct, then pull the fiber through and terminate it. That way it is protected from crush and kink problems that can often be caused by other trades working in the space later.

As always, there are minimal ways of doing installations and more 'enhanced' methods of installation that offer more protection for the installation.

good luck!


Daron J. Wilson, RCDD
Solving 'Real World' problems
 
With just a little effort fiber is just as safe in the ceilings or under the floors as copper runs. If you have someone hacking up cables in the ceilings or having cables damaged by the way they are being placed you have bigger issues that need addressed. By using Plenum you also don’t have to worry about changes made in the HVAC of a building after you have run cabling, and the cost of plenum is lower that conduit and in some cases the same cost of non-plenum cabling/fiber.


 
Perhaps it is just more design driven, but a protective raceway for the fiber is a common and practical method of protection, plus it allows for very easy upgrades (62.5 to 50 micron fiber for example).

Having watched other trades and building plumbing/steam pipe failures, having the sensitive stuff in a bright orange tube is a bit more protection than a 1/4" diameter black indoor/outdoor fiber strung through the ceiling with the copper.

As to using Plenum for everything to avoid the HVAC changes, I suppose you could run plenum everything, which is probably going to increase the price by 30% or more, on the off chance that some day they change the whole HVAC design. However, running just plenum fiber and PVC copper is certainly no great advantage. While it is a thoughtful direction, I don't think the code would require you to upgrade the existing wiring if the HVAC us upgraded.

As always, more than one way to complete a project, good ideas!


Daron J. Wilson, RCDD
Solving 'Real World' problems
 
One other method of installation that has not yet been mentioned is to use a tight buffered, armored cable. The metal flex allows for protection, it is an orange color (high visibility in a ceiling), you get to pull the cable and conduit all at once, and since the cable is tight buffered, there is no need to use a breakout kit. Then, the only main consideration is, as always, termination method. I would shy away from a pre-terminated cable unless you absolutely know the distance from end to end and can order with precision, allowing for some sort of slack loop.

Just my thoughts.

Randy
 
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