Question by Raymond Wierzbicki posted 21 May 2007
| CMR direct burial|
|I have a customer who had another contractor install standard cat6 CMR cable as direct burial, now homeowner is having problems with UTP sets. I would like to provide customer with documentation as to why this paticular cable is not intended for the installation already done. I can't find the orginal manufacturer's contact info. Cable is "ProConnect High Perfomance Gigabit Networking Cable"|
Answer by Dmitri Abaimov posted 09 Jun 2007
|Dear Raymond ,|
CMR cable are usually jacketed with PolyVynilChloride (PVC) compounds that are not designed to withstand elements, especially water that's always present in direct burial situation. The PVC will eventually swell with the water and the jacket will crack and let the water in, and the process will repeat with the inner insulation. After that there will be corrosion and electrical contact through the water that will eventually kill any signal.
That said, though, I could not find specs for "ProConnect High Performance Gigabit Networking Cable". However, if you see CMR markings on the cable, it is an indoor cable and installing it outside was irresponsible or ignorant mistake.
Dmitri Abaimov, RCDD
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