Wednesday, September 30, 2009

Pulling Fiber Optic Cable - Tips and How To Advice


Pulling fiber optic cable takes a lot of preparation. Without the right tools and knowledge, you can have a big mess on your hands.We'll go over some of the common steps to get you ready to make the pull.

1) Measure twice cut once:
First and foremost, get the correct measurement. An easy way to do this would be to fish some pull string through your conduit. Make sure to follow the exact path the fiber will take, end to end. Once your string is all the way through, attach a heavier rope to the end, pull it all the way back and measure your string. Leave the rope in place, you will be using this to pull your fiber through later. (Tip: Always add at least 15ft to the final number. It may cost a little more, but can save you a lot of time and headache if you come up a few feet short. It is also a lot easier to work with the cable if you have some slack, vs a cable that barely reaches).

2) Plan your Run:

Buildings- Although it is not necessary to run the fiber through innerduct, many people prefer this to keep it clean and professional looking. If you prefer not to use innerduct, try to keep your pulls as straight as possible. Pulling diagonal is OK, but it will make for a neater appearance if your fiber is running parallel. Get it done right the first time. If someone is unhappy with the appearance, it will take much longer to correct, or re-pull the fiber. (Tip: Never pull around corners, even if you have a helper. You should always pull out the excess fiber to the corner, laying it down in a figure 8 pattern as your doing it. Then flip the whole bundle over and continue to pull on the other side).

Conduits- It is important to plan ahead, especially if your planning on pulling the fiber through underground conduit. Just like measuring the fiber, it's very important to get this done right the first time. A general rule of thumb is to use a 1.5" to 2" conduit for the fiber pull. If your running long distances, or using a thick armored fiber, you may want to increase the size to 4". It may also be a good idea to plan ahead and install a second conduit if you plan on future expansion. (Tip: Minimize the number of bends in your run. The fewer bends there are, the easier the pull will go. If you can't get around it, install junction boxes. Also make sure to protect the fiber by putting plastic bushings on the end of the conduit).


3) Which Jacket is Right?

Outdoor - Outdoor fiber is used for all outdoor applications (except direct burial). It is flooded with a water resistant gel, which means it can be run in buried conduit. But that also means there is a 50ft limit to being run indoors due to Fire and Safety codes. For direct burial applications, we suggest you use an armored fiber. If you need to suspend the fiber for arial applications, you can buy the fiber with a messenger attached, or buy it separately and and attach it yourself.

Indoor - For indoor applications, you need to use a Plenum rated fiber. Plenum fiber complies with all Fire and Safety codes.

Indoor/Outdoor - For applications you need to run the fiber indoors and outdoors, you should use an indoor/outdoor rated fiber. This fiber can be run in underground conduit, and doesn't have the 50ft limitation for indoor use. A great all around fiber.

4) Pulling the Fiber:

Communication is Key
Pulling fiber almost always requires at least 2 people, so communication is very important. Most fiber runs are a few hundred feet or more, so yelling back and forth isn't an option. What to do? Walkie Talkies can be a great way to keep in touch with the guy at the other end of the cable. Get some with wrist straps or a belt clip so you don't have to constantly pick it up off the ground.





Lube it Up
Make sure you properly lube the fiber during the entire run. You will want to start off with a generous coat on the pulling eye and mesh. It would be a good idea to stop from time to time and apply more lube to the fiber as you pull. Always use lubricant that is designed for cable pulling, not just anything off the shelf. If you use the wrong type of lube, it may damage the jacket of your fiber, or other cables around it. It can also clog up the conduit once it dries. Cable pulling lube is designed to resist freezing and clogging.


 Use the Right Rope
We recommend using a 1/4" to 1/2" thick pull rope, not pull string. You want to minimize the amount of stretching during your pull and string isn't very good at doing that. Stretching can make pulling your fiber very unstable.




Pulling Eye Removal
Never use a knife or blade to remove the pulling eye. This can damage the jacket of the fiber, or worse, the fiber itself. Always use a pair of electrician scissors.




Stay up to Code
Honesty is the best policy. The NEC requires that cables used in premises, both commercial and residential, be “listed for the purpose” by a Nationally Recognized Test Laboratory (NRTL, pronounced “nurtle”).Always obey all fire and building codes. Never try to cheat the system just to save a buck, especially when peoples lives are at risk. If plenum rated fiber is required, use plenum rated fiber. It's the right thing to do.




5) Pre-Terminated Fiber Optic Cable
The greatest thing to happen since sliced bread. Pre-terminated fiber optic cable assemblies save you time and headache. No need for expensive tools. No need for testing. Our pre-terminated fiber comes to you on a wooden spool, with the connectors already assembled on the fiber. We have the connectors staggered by 1/2" to make it easier to pull through conduit or innerduct. The pulling eye is very strong and wont break on you. Test results are included. It doesn't get any easier than this.


To order any of the products talked about in this article, visit Discount-Low-Voltage.com
Or call us at (888)797-3697

"By Mercy Salinas"