Avoid Using Network Cable to Connect Card Readers and Door Locking Hardware

Posted by Dan DeMerchant on

I spoke with a customer on the phone that was having two problems. First is that their electric strike is not always releasing when energized and second, the Wiegand card reader is not reporting a card number on the controller reliably with every swipe. Being familiar with these issues after outfitting hundreds of door installations, it's obvious to us through our technical support notes that the correct cable type may not have been used for the application.

We asked the installer..."what type of cable was used to wire these two devices to the controller?"  Answer...CAT5 cable. We then asked, why didn't you use the correct cable types that were specified? "Because we had it on the truck and it's all low voltage!"  Wrong answer that can ruin an installation, especially considering that wire runs are the majority of labor with door hardware installs.  Why risk using the wrong cable and having to fix one of the most labor intensive part of the job? 

CAT5 cable is a particular type of twisted pair data cable that was designed to carry differential communication signals (like 100BASE-T Ethernet). These are signals that have +V on one conductor of a twisted pair and -V on the other. The twists are used to reduce electrical noise. There is not enough copper to directly run loads without higher voltage POE adapters, and there is no shielding or correct impedance to handle non-differential 5V signals like a card reader's Wiegand output, long distances. If you must connect a reader with CAT5 or CAT6, use both conductors in one pair as a single reader signal wire.

Or just avoid the whole problem and use the proper (plenum) 22 AWG shielded, multi-stranded cable for readers and (plenum) 18 AWG cable for the strike. Plenum cable is cable that creates less fumes and smoke during a fire and is required in most installations including all fire rated entrances.


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