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Do You Know What it Takes to Pull Category Cable for AV Projects?

Bob Ferguson

Pulling category cable for AV projects is easy … right?  

The answer is “yes” – as long as you follow some simple guidelines!

Like many low-voltage cables, the electrical performance of a category cable is often dependent on the cable maintaining its diameter and shape. Otherwise, impedance and signal reflection issues can arise. As a mentor once told me: “physicals equals electricals,” and that’s especially true for category cables. 

To ensure optimum performance after installation, category cables used in AV projects have guidelines and best practices that need to be followed during the installation process. For example: Did you know that there’s a maximum pull tension and bend radius for each cable you install? Exceeding the guidelines can lead to irreversible cable damage, such as a scuffed or torn jacket, stretched conductors or broken strands – all of which will impact AV performance.

Because it’s a labor-intensive process – and one that some installers prefer to avoid – cable pulling is often a job given to new technicians on the jobsite. But handing this job off to technicians who don’t have experience can create challenges when they haven’t been trained on specific installation requirements.

In a recent survey of AV installers, it’s reported that more than half of technicians are trained on the job – meaning they have no prior work experience to rely on. It’s important that your experienced installers spend time explaining the basics to newer technicians before they start a job.  

In addition to on-the-job training between installers, there are also several trade organizations that offer training and certification programs so technicians can learn the basics. AVIXA, BICSI and CEDIA are just a few examples of great resources.

Another excellent training option is to partner with a quality cable manufacturer. Who better to train you on cable installation than the people who designed and manufactured the cable you’re using?

Belden offers several training options for all needs and experience levels – from free, online classes (with lots of new ones on the way) to hands-on, onsite termination training for integrators using our cables and connectors. We’re happy to spend this time making sure installers feel confident in the process because we want qualified technicians installing our products. Even the most high-performing, high-quality cables won’t work properly if installation isn’t done correctly.

For fun, here’s a little quiz to test your knowledge about category cable installation for AV projects (don’t scroll down too far … the answers are at the end!).  

1. What’s the maximum pull tension of a Category 5e cable, 4-pair, 24 AWG (like Belden’s 1585A)?

a)       40 lbs.
b)      100 lbs.
c)       25 lbs.

2. By adding cable-pulling lubricant to category cables, you can increase pulling tension by how much?

a)       0% increase; adding lubricant does not increase tension limit b)      15% increase; lubricant needs to be rated for the cable being installed c)       25% increase; any lubricant or liquid soap can be used

3. Separating pairs removes crosstalk protection when connectorizing cables, but Belden’s Bonded-Pair Cables can eliminate this with the use of a REVConnect Jack.

a)       True b)      False

4. How many Category 6A cables fit into a 1 in EMT conduit without exceeding the recommend fill ratio? (To make the math easy: Belden’s 10GXS13, one of the smallest-diameter cables, has a diameter of 0.265 in and an area of 0.055 sq in; conduit has an area of 0.864 sq in.) 

a)       5 b)      7 c)       12 d)      6

5. Which PVC pipe diameter can be used to control bend radius for a 0.25 in category cable?

a)       1 inch b)      2 inch c)       4 inch

So … how’d you do? Did you pass the test? (Answers are below!) This is the type of information technicians and installers need to know before they begin any AV cable installation project.

If you need help understanding requirements and best practices for installing and terminating cables on a specific project or application, send me a note. I’m happy to give you the information you need.

 

ANSWERS:

1. c (anything more and it damages the 24 AWG conductors)
2. a (adding lubricant reduces pull tension, but it does not allow you to pull more – and always be sure to use the correct type of lubricant)
3. a (to maintain performance, it’s critical that you separate or untwist as little as possible)
4. d (round down; area pipe 0.864 * 40% = 0.3456 / 0.055 [area of cable] = 6.2836)
5. b (bend radius is four times the diameter; 2 in pipe has a radius of 1 in or 0.25 in x 4)