DComTalk.com

Carl Navarro · Guest

I had an old customer move into a new location that had been vacant
for a couple of years. It had an ICC patch panel and 8-pin jacks with
all wires terminated in duplex jacks at each location.

As we did the walk-through, I noted the Cat-3 wiring, but since the
customer is going to use a VPN and no file-server on premise, it
seemed that 10-base-T would be doable on Cat-3 without running new
cable.

The building had an ample crawl space with visqueen on the floor and
all the greenfield ran down. The patch panel was mounted on an
outside wall about 6 feet off the floor, a single gang old-work box
turned sideways, and everything appeard O.K.

After the KSU, VM, and 7 phones, and the 3 outside phone lines were
ordered, I got my first surprise. The customer wanted to add two
desks in a room that had outlets with no cable. No problem, that's an
extra. I grabbed my 4 boxes of wire, fish tape, green sticks,
flashlight and ladder and headed for the crawl space.

Upstairs, I taped a voice and data cable to my tape and pushed them
down into the crawl. I took the green sticks and I could feel the
plate on the wall under the patch panel, so this should be a piece of
cake!

Oops, the idiots had actually stuffed 14 cat-3 cables in a 3/4 inch
greenfield, run through a single gang box on the way to the patch
panel, and, of course, since I was not supposed to do any crawl space
work, my right angle drill was in the warehouse. Well, no matter, I
installed the phone system and set 5 phones up and saved the data and
crawl space work for the next day.

Day 2

I get all my new cables in, set the last 2 phones and test the new
jacks and everything is great. Now to map the rest of the jacks....
I plug my tester in and it indicates split pairs on pins 3-4-5-6.

UH OH!

All 16 existing jacks were wired straight color code 1-8! I guess it
had never been used for data and the phone system didn't mind the
split pairs when the longest cable was 60 feet. The jacks were the
ICC tool-less Insulation displacement (the cap cinches the wires) and
there is no wire guide on the jack. I guess the installer didn't know
that you have to apply a T-568 A or B to the pins.

Sigh, time to rewire BOTH ends.

Fortunately, I only had to rewire 6 jacks. I left 2 locations on
voice pair split and am going to install 4 data cables on one side of
the room at a later date.

If anybody wants to know, you peel off the wires on 1-5, move the
white green to pin 3, move the orange pair to 1&2, and turn the blue
pair over and put them on 5&4.

Piece of cake :-)

Carl Navarro

	DComTalk.com Forum Index -> Cabling	All times are GMT
Page 1 of 1