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Old copper wiring plant issues

Old copper wiring plant issues

Old copper wiring plant issues

Trying to get out of a potential nightmare. Power generating plant built between the 60's and 80's has an extensive copper wiring plant between an old telco CO that once hosted a DMS-100 switch for Centrex (since replaced with a Nortel 81c), that connects out to the various buildings on site.

Issues with bad pairs are commonplace here - most likely due to two generators kicking out 345kv out the grid 24/7, and Sidekick stress tests are unfavorable for many pairs I come across.

We have a large unused block of pairs - about 1000 - that the telco never used to connect one telephone room to another. Plan is to add 400 more phones - and management is insisting on using existing copper - rather than go with fiber remote gear to bring over to the other telephone room.

Am I right to assume that unused pairs over a period of time - even if they've never been used? Or am I reading too far into the Sidekick test results?

80% of the the unused pairs failed the stress test (that is what the Sidekick says is bad for spans of 2,300 feet - anything over 17db) - and while they may be useable, it'll just create headaches galore during implementation and trouble tickets down the road.

That and the BIX frame where the Nortel PBX is located is one of those back-to-back deals (feepairs on one side, PBX on the other - hate those things).

Seriously trying to avoid what management thinks I should do and sell them the more costly fiber remote option for the sake of quality and reliability (which in the long run will prove to be even costlier).


RE: Old copper wiring plant issues

You're in a tough situation - going into a project with known issues is a no-win deal. Do they have existing Ethernet between buildings that you can ride?

RE: Old copper wiring plant issues

Nope - need to run 400 analog lines to a legacy SpectraLink 30000 system over a 2,300 ft span of copper pairs (there's 2700 total pairs - about half in use, about half of what's not used bad/questionable). Plenty of fiber I could use - so rather go that route with some fiber media converters and locate some of the SpectraLink stuff next to the PBX instead. While parts costs would be higher, they would be offset in part by labor savings and headaches down the road.

RE: Old copper wiring plant issues

Most issues with copper cabling all go back to how well it was installed, if it was installed correctly and to standard then there should be no issues and long lasting

I believe the issues that you may be experiencing with faulty cable pairs etc maybe down to the isolators/protection modules that should be fitted to both ends of any telecomms cabling at this site to protect the equipment or the lack of them?

some of theses isolators/protectors are subject to the ingress of damp etc and may cause issues with your cable testing results.

I can see your argument for utilizing the fiber but i think you may be in for a hard sell?

Ideally the remote sites/buildings could use IP phones? However there maybe some issues with continuity during emergencies etc?

power generating sites will have specific grounding issues that must be adhered to otherwise a noisy line might be the least of your worries!

RE: Old copper wiring plant issues

Everyone is quick to blame cable and tests to say hey this wont work. Truth is copper is copper, if not corrupted by outside elements, ie water, emi, or excessive distance(2300 ft is excessive) then its fine, Its when we expect something to do something that it wasn't designed for that bad things happen. Manufacturer specs for the cards powering any circuit will give you the max distance of anything that runs on them, if you're looking for a long range solution of Ethernet packets over voice copper at good speeds look at dslams and vdsl endpoints. I've recenty used versa vdsl endpoints with great success in enterprise solutions.

RE: Old copper wiring plant issues

Nortel digital phones typically are good to 3,000 feet. Problem is - most of my copper runs from the PBX to the endpoints are over 2,500 feet (I have a 2700 pair from the PBX to another MDF in the plant that's 2,400 feet then feeds out to the IDF's around the plant). That and it's a 2,000 megawatt power plant so we have EMI and the fun of flooded manholes and brutal upstate NY winters. Eventually we'll replace it all with a Cisco system in a few years. Until then.........

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