Shielded Ethernet with Unshielded Hardware - Don't Do It!
Written by Don Schultz, trueCABLE Senior Technical Advisor, Fluke Networks Copper/Fiber CCTT, BICSI INST1, INSTC, INSTF Certified
One of the most important things to realize when terminating shielded Ethernet cable is that in order for the cable shield to function properly it must be terminated in such a way that it can drain off to ground. What are the risks if you don’t properly terminate your cable shield?
- Ineffective or non functional cable shield (you just wasted money!)
- Floating cable shield that may function as a source of interference or attract unwanted interference (rare, but it can happen)
The process of making a low resistance electrical connection to ground is called bonding. A more appropriate way of characterizing this is bonding to ground. Typically, this is done via your existing AC system ground. In your home or business, there is an electrical system that (should) be equalized to earth with a grounding electrode. Grounding electrodes are usually ground rods. For extremely detailed information about how to complete a bond to ground in a residential or small business office setting, please see Residential Bonding and Grounding of Shielded Ethernet Cable Systems. For more advanced commercial installations you will want to take a look at Commercial Bonding and Grounding of Ethernet Cable Systems.
The Right Way
In the process of terminating your Cat6A Shielded Riser cable, for example, the cable shield is bonded to your termination hardware and the termination hardware literally functions as an extension of the cable shield. How does this work? Well, it can look different depending upon the termination hardware and accessories that you are using, but we will use a Cat6A Shielded Tool-Less Keystone Jack as a reference point.
Shielded Ethernet cable. Cable shield and drain wire folded back to make metal to metal contact with the shielded keystone jack.
The exterior of the shielded keystone is now literally functioning as an extension of the cable shield. Using a shielded patch cord continues this bond, and so does using a shielded toolless patch panel.
The Wrong Way
Unshielded Cat6A keystone jack. There is no provision to terminate your cable shield.
Will using an unshielded keystone jack work at all? You will be able to pass data, yes. That said, you won’t have any way of bonding your cable shield to the termination hardware and therefore no way of bonding the shield to ground. What could go wrong? That is up to Murphy’s Law.
So, there you have it! A quick blog and video demonstrating the correct way to terminate shielded Ethernet cable. Remember, Ethernet cable installations are systems and all parts of the system must be installed properly to achieve an effective and efficient structured cabling system.
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