Last weekend I was up at the telephone museum and was tasked to install a building entrance protector to bring dial tone from the main museum building to the visitor's center. The building entrance protector was already installed in the basement of the visitor's center, done by a cabling contractor. Full disclosure: this was my first time installing a building entrance protector. I want to review how I terminated the cable to make sure if I do another one, that I improve on it. I couldn't seem to find any videos online on how telco splicers do this.
I was working with a 25-pair outdoor direct burial cable, like
this. Terminated to a Commscope 25-pair building entrance protector.
Initially I started by stripping back the PVC jacket by a 1.5ft. Then I realized how easy it was to lose the twists in the pairs, so I started over again but only stripping back about 4" of the PVC jacket. Then I carefully unfolded the aluminum sheath, then grabbed each pair and putting small twists in the end of each, so that the pairs wouldn't get lost. Then I cut back the rest of the PVC jacket. Finally I cut back the aluminum sheath so that only 1" was visible. Then I took one side of the metal sheath ground clip and slid it under the aluminum sheath with teeth facing the sheath, but in front of the cable pairs. So from inside out: cable pairs, clear plastic jacket, metal clip, aluminum sheath, outside metal clip, and nut. Since I was only working with 25-pair, I cut off the binder ribbon and string. Otherwise I would have left that intact.
The part I was a little unsure about was a plastic piece about the same size as the sheath clip. I assume it goes behind the metal clip and in front of the cable pairs, to protect them from pinching/damage/shorting. So I slid it in there, then put the other side of the metal sheath clip on, teeth facing the outside of sheath, and screwed it down with the nut. Then dressed with a few wraps of 3M 33+ electrical tape from the PVC jacket all the way up to the nut.
Then I punched down all 25 pairs according to the color code, wh.blue/blue, etc. I tried to leave a little slack, but it ended up being kinda tight, not banjo wire tight, but a little snug.
Things I know I need to do better: leave more slack, get cable wipes (paper towels are kind of useless in just spreading the icky pic everywhere), and memorize the 25 pair color code (I had a cheatsheet but started getting the hang of the color code after awhile).
On a side note, I had another volunteer put his buttset on the blue pair in the visitors center, while I put my Fluke 3000 toner in continuity/battery mode and used my buttset to establish a talking line. Very cool. I've read about this but had never done that until this point. Then I had him put a short across each pair and used my Sidekick to test each pair to be sure I had continuity. Wiring was already terminated in the visitor's center and a few key sets already hooked up. We discovered that the lamps in the key sets will not show a short until the protector was pulled on that pair.
