Why is Network Cabling Different?

A lot of the skills that an electrician applies every day are directly applicable to network cable installation. But there are differences, and that’s what I will be covering in this section.

Network Cable is Delicate

Network cabling is lighter gauge than electrical wiring. Any kind of rough handling has the potential to damage the cable before you’ve even installed it.

CAT5e or CAT6 cable has 4 pairs of intertwined thin copper wire. Damage to any of those 8 wires renders the cable unusable. Do not exceed 20% of the maximum cable strength when installing (or at any other time for that matter).

Bend Radius

You need to pay careful attention to the minimum bend radius for the cable type you are using. The cabling may well be okay when it’s finally installed, but if it has been bent too sharply during installation one or more cores may be cracked and the damage may have already been done.

Minimum bend radius differs with each type of cable, but for most multi-core cables, don’t bend tighter than 10 times the cable diameter.

Bending cable in order to pass it through a confined space is a no no. Better to cable pull, and then cut off the length of cable used to anchor the string.

As always, your cable manufacturer/supplier will be able to tell you exactly what the minimum bend radius is.

Cable Insulation

Network cable insulation is much more delicate than regular electrical cable and any nicks, cuts, scuffing etc. will affect the quality of the final signal, an important characteristic of the finished installation. Be particularly careful that nothing rubs on sharp edges which might cut through the insulation. If you need to lubricate a trackway check with the cable manufacturer/supplier for the correct lubricant.

A wide range of insulation types is available. Check the fire regulations to ensure that the cable insulation is correct for your installation.

Electrical Interference

Network cables are sensitive to electrical interference, keep them well away from any source of electrical noise, transformers, motors, lighting ballasts, and if at all possible don’t run them next to mains cables.

Pay careful attention to firebreaks and seal gaps with appropriate materials. But, as an electrician, you already know all about fire regulations and the like.

Terminate Carefully

Terminate the cables correctly, don’t leave any pairs untwisted and make sure all the crimps are secure. If the cable isn’t terminated correctly it will NOT work properly. Each pair has a different amount of twist, try to maintain this right up to the crimp.

Labeling

A lot of electricians don’t label things. That can be okay when installing in a domestic setting. So long as a power outlet works then the householder or building contractor is unlikely to care whether it is labeled or not.

In a networking context, labeling is crucial. Each cable run must be labeled carefully, at both ends. You are likely to have a large number of cables and it’s very easy to get things mixed up.

With modern structured cabling, especially when network, video and telephones are combined onto a single infrastructure it is important that the outlet to which a particular cable is attached to at the patch panel is clearly and correctly labeled.

A label printer really helps, they don’t cost much, and if you plan carefully you can pre-print the labels before you go on site.

Configuring even a relatively small network without proper labeling is a nightmare. Labeling after the installation is very laborious and time consuming.

Test: if it’s worth building, it’s worth testing

Another major difference between regular electrical work and network cable installation is testing. Many electricians don’t test their installations in any kind of systematic way and with data cabling it’s not just the connectivity that’s important, but also the quality of the connection.

The bigger the job, the more important cable testing is likely to be. In fact, on even medium sized jobs, you will find that strict standards have to be tested against and extensive reports produced for every cable installed.

The up side is if you leave the job fully documented and tested you can present your bill sooner.