sundance-communications.com/forum Forums Wiring - Telecom Carriers - Trunks & Services Cabling Telephones Systems Wiring Is "Doubling-up" on CAT3 telco cabling acceptable?

Amigo's,

I was recently made aware that one of our telecom wiring vendors was "doubling-up on the copper" on new CAT3 telcom drops for a new phone switch being deployed at one of our office buldings.

Is this an acceptable practice in the Industry? Does it meet wiring code?

Thanks for the feedback!

Dave:

It's absolutely acceptable, no different than a 25 pair cable that carries 25 separate extensions or a 2,700 pair cable carries thousands of phone lines and circuits in the street. It has been done as long as phones have been around. Cable is constructed with the pairs twisted at varying lengths to ensure that their magnetic fields don't interfere with each other under the same jacket.

Now, I will say that it isn't generally accepted by some of the NEW "regulatory" athorities, such as BICSI, EIA/TIA, etc. They provide standards to follow, not enforceable rules.

As far as the National Electrical Code, which is the only regulation that can be forced upon you, there is absolutely no restriction on how pairs in cables can be used.

TIA/EIA's standards are there to ensure that a jack is wired the same worldwide in a nutshell, but it cannot be enforced (required) unless a customer or architect mandates such for a site. Even then, it's frequently (and wisely) forgotten after occupancy in new construction takes place.

Keep in mind that running a four-pair cable is for a reason; so you have three spare pairs to use for other things. If it was so horrible to share cables, then we would all be running quad-shielded one-pair cable, in 4" rigid steel conduit to each outlet.

Now if they charged you for two runs and only split one, you might have a financial reason to complain, but other than that, you are fine, absolutely fine.

Thanks for the thorough explaination on this Ed; as usual the forum comes through!!!

Hey Dave were have you been?
Haven't sceen you around in a while.
Is that car dealer AA doing OK?