You go into an e-shop to buy a 100 meter coil of Cat6a cable. You see the first option at €60, and just below that, another coil that also says "Cat6a", but costs just €20. The visual difference is zero. The saving instinct tells you to get the cheap one.
Don't do it. If you run this cable inside your walls, you've just planted a "ticking time bomb" on your network.
The huge difference in price is not due to marketing, but to the metal itself. The industry, in order to lower costs, created a class of cables called CCA (Copper Clad Aluminum). As engineers, we strictly forbid their use in structured cabling. Let's take a look at what CCA is, how it tricks the eye, and why it's extremely dangerous for your equipment.
The acronym CCA stands for Copper Clad Aluminum.
Because its outer surface is copper, if you look at the end of the cable with the naked eye, it looks completely normal. However, his "heart" is the wrong metal.
Why is aluminum so bad for data networks?
Aluminum has about 55% more electrical resistance than copper. This means that the data signal gets "tired" much faster as it travels. * While a pure copper Cat6 cable can guarantee a speed of 1 Gbps at 100 meters, a CCA cable can start losing data packets (Packet Loss) and drop the speed to 10 Mbps once it exceeds 30 or 40 meters. No CCA cable can pass official certification tests (Fluke Test).
This is the most critical reason. Today, the network cable does not only carry the Internet. It also carries power through PoE (Power over Ethernet) technology to power security cameras, Access Points and IP phones. Due to the high resistance of aluminum, when you try to send power (especially to new PoE+ devices that require 30W or 60W), the cable acts like a stove resistor. It overheats dramatically. In extreme cases (if there are many such wires crammed together in a pipe), the insulation can melt, shorting out your expensive equipment or even causing a fire inside the wall. For this reason, IEEE standards specifically prohibit the use of CCA in PoE applications.
Aluminum is a hard and brittle metal. When the electrician pulls the wire through the conduits or bends it to plug it in (Keystone), CCA conductors break much more easily than flexible copper. Additionally, if exposed to air, aluminum oxidizes rapidly, completely destroying the electrical contact in the plug after 1-2 years.
Unfortunately, many stores sell them as normal, often without a clear warning in the title. How will you protect yourself?
Structured Cabling is an infrastructure that is "buried" in the walls and is expected to work without interruption for decades. CCA cable is a dangerous illusion of economy. The extra 30 or 50 euros you will pay in total to buy 100% Pure Copper cable, is the most important "security" you will buy for the speed, stability and integrity of your expensive IT equipment.
Next Step: The correct (copper) wires are in, the sockets are in, everything looks ready. But how do we really know if the installation can handle the speeds it promises? It is not enough to just turn on the Internet light bulb.
We continue to the next Class A guide: Network Certification (Fluke Testing): How Engineers Check Losses, Crosstalk and Cable Length.
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