Copper Cable Installation Best Practices: Be Aware of the ‘Why’

Author: Christie Ketchum

Bad installation habits will likely affect copper cable performance. An experienced installer outlines best practices—and why they’re important to follow.

Sometimes, the ICT industry overcomplicates things.

When it comes to installing copper cables, overthinking can create unnecessary challenges and problems. Plus, time spent ruminating can be a trap that creates delays and indecision, diminishes productivity, drains mental energy, produces additional stress, and hinders a team’s ability to adapt to unexpected situations. 

To prove my point, consider this question (it’s one I often like to ask technicians and installers): “What color is copper?” 

How would you answer? Surprisingly, the replies I receive vary. For example, I’ve heard responses like:

• “It’s brown.”
• “It seems to be somewhat blue-ish.”
• “I think it’s kind of green.”
• “Is it orange?”
• “I don’t know!” 

It may seem like a trick question, but it isn’t. The answer is straightforward: Copper is the color copper! Rarely do industry professionals answer the question this way, though—because they’re overthinking it. 

I ask this question not only to illustrate the point that we tend to overthink, but also to open the door to conversations about proper copper cable installation techniques.

It doesn’t matter what type of data is being transferred: Network cables, speaker cables, and access control cables are all copper cables. Information travels down each of these cables in the same way, and the cables are installed following the same best practices and approaches. In other words, the methods (installation) are always the same, regardless of the means. Keeping best practices in mind will help prevent overthinking. 

3 Examples of Why Installation Practices Matter

While there are good reasons behind every one of the industry’s established practices for copper cable installation, I’ve seen many installers dismiss the guidance we’re about to present. 

Often, this happens not because they’re trying to ignore recommendations, but because they overthink the process or haven’t been taught how their work can positively or negatively impact the cable’s performance. While comprehending the inner workings of a cable may seem like something installers don’t need to know, having this knowledge helps explain the “why” behind the rules of copper cable installation. It prevents overthinking, stops installers from taking shortcuts with negative consequences, and makes a difference in the end result. 

1. Nicking a Copper Conductor

If you don’t know how copper cable works, then nicking the conductor may not seem like a big deal during installation. Chances are high that installers would be more careful if they knew that even a small nick in the conductor:

• Decreases the cross-sectional area of the conductor, which leads to increased resistance and affects the flow of electrical current.
• Causes weakened areas at the break, creating an open circuit that can’t maintain electrical continuity.
• Generates excess heat at that point in the cable, resulting in insulation damage or cable failure.
• Prevents electrons from traveling along their intended path, which can reduce transmission speed. 

2. Flattening the Cable End

Here’s another example: using snips to flatten the end of the copper cable before installing an RJ45 connector. Almost every installer has done this, but did they realize the problems the action may cause? 

Flattening the cable end can nick the conductors (causing some of the problems we discussed above), but it can also:

• Compress wires, which changes a cable’s performance characteristics (electrical resistance, signal integrity, etc.).
• Cause conductors to lose their separation and become misaligned, making insertion into the plate’s slots more difficult and creating performance issues.
• Make termination more challenging and affect proper connection. 

3. Pulling Cables Too Hard

While calculators exist to help you determine how many cables can fit into a certain pathway, using common sense is also critical. In other words, don’t add so many cables to a bundle that you can’t pull it through the conduit or pathway. 

Don’t overthink it. If the bundle doesn’t fit, there are two ways to remedy the situation (notice that “pull the cables harder” isn’t one of the choices):

• Reduce the bundle’s cable count
• Make the pathway bigger 

Case in point: I once watched a group of six installers attempt to pull a bundle of network cables to a nurses’ station through a small pathway (the carpenter didn’t cut the hole big enough). With this much pressure being applied, their cables were being pulled and stretched. As a result, their electrical characteristics changed, and the cables wouldn’t operate as designed. 

Trying to pull a cable bundle through a tight pathway can have detrimental effects on performance and longevity:

• Using excessive force stretches the cable beyond its intended limits and weakens internal components (such as conductors and insulation), which can result in errors, slow speeds, and intermittent connectivity.
• Pulling too hard can cause conductors to deform or break, creating signal loss, poor connectivity, or failure. 

In this case, the installers had to cut off the cables they damaged and repull the bundle. 

Best Practices to Follow for Copper Cable Installation

Because information travels on the outside of copper cable, it’s extremely important to use proper tools and follow installation best practices. Bad habits will likely affect performance. 

Based on my years of experience installing copper cable (and then training installers), here are some of my recommendations to ensure success. These rules apply to any copper cable being installed. There’s no need to overthink the process.

1. Don’t use electrician’s scissors to score the cable jacket.This can nick the conductor, which (as we explained earlier) causes cable-performance degradation, weakness when terminating, and potential cable failure. Use a stripping tool, and make sure that the tool you use is appropriate for the cable type (UTP, shielded, etc.).
2. Don’t use electrician’s scissors or other tools to straighten conductors.This can flatten conductors and alter electrical characteristics. Depending on whether you’re terminating RJ45 connectors or outlets, performance problems can arise as a result of doing this. For example, it can lead to the removal of too many twists or can narrow the information pathway (leaving no way for information to be received on the other end of the cable).
3. Don’t kink the cables as you pull them.A kink can break the wire and affect conductivity. It can also cause permanent damage to conductors and/or insulation and create signal loss, as well as violate the recommended bend radius of the cable. Finally, it may weaken the cable’s mechanical strength (its ability to withstand external forces).
4. Don’t stretch or over-pull your cables.When copper cables are pulled too hard during installation, you can damage the cable jacket, which compromises its ability to protect the conductors from moisture, chemicals, and physical wear. You may also elongate the conductors inside, which negatively impacts electrical resistance and signal transmission.
5. Don’t pull cables from the box incorrectly.Pulling too much cable from the box at once allows the cable to loop inside itself. When this happens, it can lead to tangling and knotting, which makes it challenging to unravel during installation (especially without causing damage). As the cable is pulled, the loops could tighten, which increases tension on the cable and may exceed minimum bend radius requirements.

Belden Is Your Installation Resource

Remember: Copper is copper. Don’t overthink or overcomplicate the work. Installation best practices remain the same, no matter what kind of copper cables you’re installing. 

If questions come up during installation, Belden’s team is here to act as your advisor. 

Ask us your cable installation questions. 

Related Links:

• Cable Combing for Cat-6a Cabling
• Fact or Fiction: 5 Ethernet Cable Installation Myths Debunked
• Shielded vs. Unshielded Cables