When pulling CAT 5 (and other types) of network cable, it is important to remember a few things. The small gauge conductors inside unshielded twisted pair (UTP) cables are easily broken when too much force is applied to them while you're pulling them. Most manufacturers recommend that no more than 35 to 50 pounds of pressure be applied to this type of cable. Also, these types of cable shouldn't be bent sharply around corners. Bends should generally have a minimum radius of no less than 5 inches. UTP is also subject to electronic distortion in the form of radio frequency interference (RFI), most often from the ballast transformers found in fluorescent light fixtures. This means that network cables should be run at least 3 feet away from these fixtures to minimise signal loss. Before you start to pull cables in for new drops, take a few minutes to plan your run. The fewer sharp bends and wall penetrations you have to make, the easier the pull will be. Also take into consideration the possible need for additional drops you may need in those areas in the future. It's always a good idea to run a pull string with your cabling in anticipation of future growth. This will help reduce aggravation and duplication of effort down the road. Determine if you need to have conduit or wire-tray installed for the cabling or if you can get by with free-span cabling. If you free span the cable (run it loose above the ceiling or its support system), do you need to run regular CAT 5e or the much more costly plenum-rated cable? Plenum-rated cable has a plastic jacket that is specially formulated to be self-extinguishing and to not produce toxic fumes when burned. Get the right tools
Fishing cable through finished ceilings and walls is much easier to do if you have the right tools. After years of trial and error, I have assembled the set that suits my needs. Aside from the basic hand tools that every tech should have, such as screwdrivers and pliers, my set includes some unusual items, such as a telescoping fishing pole, an old slingshot with a cheap fishing reel mounted on it (I saw one in a catalog and made one of my own), a good cordless drill with a large assortment of bits, a piece of bead chain about three feet long, a magnet fastened to the end of a short piece of steel fish tape, a bucket of pull string (readily available from most electrical supply houses) and a small (1 gallon) shop vacuum. Each of these has been invaluable in helping make my job easier. Buy vs. build
Just because I chose to make my own cable pulling aids doesn't mean you have to. Commercially produced versions of all these devices (and many others) are readily available from many of the national specialty catalog outlets. Most of them are very reasonably priced, so even IT departments on tight budgets can afford such labour saving devices. In most newer office buildings, above the ceiling is where builders hide ductwork, fire sprinkler piping, and electrical conduit that the occupants take for granted. Even with all this other stuff up there, you can usually find enough open space to install lots of new cables. When I have to run cable across a ceiling, I can tape a string to the end of my fishing pole and reach across as much as twenty feet of ceiling without having to pop every second or third ceiling tile along the way. If I have to span a longer distance, the slingshot comes in handy. Using it, I can throw a string across fifty or sixty feet of ceiling. To avoid loosing sight of the end of the string (and to add a little mass) I tied a bright yellow plastic casting practice plug to it. The soft plastic plug weighs less than an ounce and has yet to cause damage or injury on a job. Once across the ceiling, a helper can tie on the pull string and I reel it back to me without me having to move my ladder! Once I have reached the wall where the new network (and/or phone) jack is to be mounted, I drill a 1/2-inch hole in the top plate and drop a length of pull string with the bead chain tied to it. I can fish it out of the junction box cutout using a piece of fish-tape with a shallow hook bent on the end or with the piece of tape with the magnet on the end. With the string in hand, pulling the cable in is easy. Many people use cut-in junction boxes made of plastic or steel to mount their RJ45 jacks. Others use open backed trim rings that just clamp into the wall cutout. I generally use plastic boxes with folding wings on them because they can be easily removed if necessary and are very inexpensive. Once you have the cable(s) pulled in, you can terminate and test them.
For a weekly round-up of the enterprise IT news, sign up for the
Enterpise newsletter. Find out what's where in the new Tech Update with our
Guided Tour. Tell us what you think in the
Enterprise Mailroom.
Enterpise newsletter. Find out what's where in the new Tech Update with our
Guided Tour. Tell us what you think in the
Enterprise Mailroom.
