Smart Buildings

Shielded vs. Unshielded Cables: What's the Right Answer?

Ron Tellas

Balanced twisted-pair cabling (also known as Category cabling or Ethernet cabling) has its roots in telephone wiring. Over the past several decades, however, it has permeated the market in other ways.


On a daily basis, it’s being introduced in applications that range from AV and broadcasting to 5G and Wi-Fi—applications that have rarely used balanced twisted-pair cabling to deliver power or data until now. Today, nearly every technology or type of environment can make use of balanced twisted-pair copper cabling systems.


Category cabling is sometimes presumed to be a commodity—something that’s easily interchangeable. But cabling is so much more than a ubiquitous product that has no differentiation from one cable to the next. Cabling products are not uniform or identical. Their performance depends on where and how the cables are designed and manufactured.


This is important to understand for one reason: Category cabling is the basis of an organization’s network. It makes technology, communication and collaboration possible, and it’s just as crucial as the foundation that supports your home.


If your foundation isn’t strong, then nothing else will be, either. Using the wrong cables to build your foundation could delay information transfer, interrupt streaming media, extend download times or shut systems down entirely.


Concerns About External Noise with Category Cabling


When building this foundation, one factor that many professionals new to Category cabling worry about is electromagnetic interference (EMI) from things like motor controllers, fluorescent lamps, etc. As more IoT devices are deployed, there’s an increase in wireless signals traveling through the air. It’s important to make sure your cabling system has an acceptable level of electromagnetic compatibility (EMC) to be immune to EMI.


Two Ways to Manage Noise: Shielded vs. Well-Balanced Unshielded Cables


You have two options to manage the impact of noise: properly shielded cables or well-balanced unshielded cables.


One way to improve EMC is to focus on cabling system balance. Well-balanced unshielded cabling systems are much less susceptible to external noise than unbalanced systems, and they experience fewer performance errors caused by interference.


Meanwhile, shielded cables feature a barrier that surrounds the cable’s signal-carrying conductors. This barrier protects the signal by conducting noise to the ground. There are different types of shields to consider, like foil or metallic braids. Selecting the correct shield is critical to ensure proper performance. If the wrong type is selected, or the shield isn’t grounded properly, then the shield can act as an antenna and pick up unwanted signals.


There are many other considerations with shielded vs. unshielded cables, too: Shielded cables are not as flexible, heavier to maneuver, larger in diameter (which can limit installation possibilities) and more expensive to purchase.


If you’re using Category cabling for the first time and pondering shielded vs. unshielded cables, you may assume that shielded cables are the best and most obvious choice to manage external signal interference. In many applications, however, shielded cabling systems can lead to unintended consequences, such as high material and labor costs. They can even invite more unwanted noise into the system if not properly designed and installed. This degrades data throughput and negates the purpose of the shield.


Often, a well-balanced unshielded cabling system can protect against signal interference just as well as a shielded cable—but in a more cost-effective way. Instead of using a shield to protect wires, the wires of an unshielded cable are wrapped in an overall jacket without a grounding barrier surrounding them.


This makes unshielded cables more flexible, smaller, and faster and easier to install than shielded cables. They don’t require grounding, and they’re also less expensive to purchase.


We recently created a white paper to explore the answer to the age-old question comparing shielded vs. unshielded cable. In this piece, we walk through the importance of understanding and classifying your environment before making a cable selection. Understanding your space will help you decide whether you needed shielded vs. unshielded cables. In addition, we explore the electrical requirements for balanced twisted-pair cabling, describe the test we performed with the IEEE (the Institute of Electrical and Electronics Engineers) 802.3 Ethernet Working Group to evaluate the performance of our own unshielded cables in industrial environments with external noise. Finally, we provide our recommendations to help you minimize signal interference in your specific environment.


Download the white paper now to better understand whether well-balanced unshielded cabling or shielded cabling will work best in your environment.


Related Links:


Shielded or Unshielded Cable White Paper

Selecting a Mission-Critical Category 6A System to Meet Increasing Network Demands

Finding a Category 6A System to Support Emerging Wireless Technology