ISE Magazine, November 2017

I S E I C T S O L U T I O N S E D U C AT I O N 8 More About Cable Locating Last year I wrote a column on locating fiber cables Colin Ward from Norscan offered some comments that I think might be helpful to you Hi Don I recently came across your 5 Questions About Fiber Optic Bonding Grounding and Locating article http www isemag com 2016 09 5 questions about fiber opticbonding grounding and locating and its sparked some interesting discussion around the office I wanted to share our thoughts with you The line that stuck out the most to us was this one Assuming that fiber cable locating is the only reason to ground the sheath or locate wire why not just do it during cable locates and then remove the ground when the locate is completed We had a couple of thoughts regarding this point First off we believe there are other reasons to ground your sheath or wire namely to protect your cable from dangerous transients such as lightning strikes When lightning strikes it searches for the best path to ground and that can very easily be the cable armor This can cause tremendous damage to the cable Over the years weve seen many cables end up looking like this after a lightning strike See Figure 1 By not re grounding the outside plant we force transients to escape through the sheath and pierce the protective layers Hard grounding delivers the transient to ground and therefore limits the potential for damage This leads us to our next point regarding locating While we believe its important to keep your sheath grounded doing so does limit the distance the locate signal can travel Just like a transient strike the locate signal can only travel as far as the next ground point This translates into a lot of extra effort on the part of the locator as he will have to repeatedly setup his portable transmitter after each grounding point In response to creating greater efficiency when locating cable we developed a system that keeps the cable sheath grounded at all times when not locating and lifts the ground when locating to allow the signal to pass through This ensures the cable is protected from dangerous transient surges while also enabling the locate signal to travel far distances We also have a system that eliminates the need to physically access the outside plant with a portable transmitter when locating If you would like more information you can contact me Colin Ward Norscan Instruments colin ward@ norscan com Thanks Colin OSP EXPERT Don McCarty is the OSP EXPERT columnist for ISE magazine discussing the issues around provisioning testing and maintaining copper for all services from POTs to IPTV Don is also president of and the lead trainer for McCarty Products a technical training and products company training field technicians cable maintenance installation repair and Central Office technicians and managers For more information email dmccarty@ mccartyinc com or visit www mccartyinc com Figure 1