atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services Outside Plant OSP Construction Very High Pair Count OSP Copper Cable.

A few days ago, I found a group of color charts that was put out by General Cable. The charts covered the standard 25 pair color code in addition to binder color combos and spare pairs.

One diagram covers cables with 4200 pairs. The document refers to any cable with more than 100 pairs as a Super-Unit.

What was it like working with very high pair count cable? I understand locating a certain pair required identifying specific binders. But what was it like installing/terminating such a cable? What technique was utilized to keep pairs from escaping from binders and getting mixed in with other groups?

The key to keeping binders together is to be sure to bundle them permanently THE MINUTE that the sheath is removed. There are special color-coded cable ties made for this, or often people just use scraps of wire of the appropriate color to secure the binders. In large counts like this, they used 300 pair super groups in order to maintain the finite number of colors available in the telecom color code. Each of these binders contains twelve regular 25-pair binders within an overall binder to keep them together. Generally, any cable over 2,700 pairs is only used in duct runs between the CO via manholes. You won't see cables this large in an aerial environment since they are nearly 4" in diameter. They usually originate in the CO's cable vault and only travel a short distance, tapering down to multiple smaller cables at each manhole splice. Their gauge (AWG) is also much smaller than traditional 24-26 gauge ones because they have to be under 3.75" in diameter to fit within standard 4" ducts. Believe it or not, these can be as small as 30AWG, which requires very careful splicing practices. Today's installations are usually heavier in fiber deployment to remote terminals that branch out into large copper distribution cables further out from the CO, which dramatically reduces congestion in cable ducts and vaults close to the CO. Although I've seen splices of 4,200 pair cable before, I've never worked with it. It's certainly not as easy as a 600 pair one would be.

I was never a splicer, but I worked with one a lot when I was on the line crew. In our area, a big pair count would be 1200 pair. We worked on some 300 and 600 too. Like Ed said, keep the groups together from the start. Those cables weren't filled with grease, so it was very easy for a pair to get lost. Split pairs would make you the talk of the coffee table the next day. We had a special bag that held 4 inch colored ties for all the colors. It could be hung from a support so it was convenient to grab the right colored tie when you needed it. I still have mine.

Some of our work was done in manholes, but I remember doing some aerial work where a riser cable, from a manhole, spliced into an aerial boot. For example, a 300 pair riser spliced to a 100 pair going one direction and a 200 going another direction. So, you had to know your cable count for that terminal, and have good cut sheets. I ran into an old splicer last week who happens to still be contracting. He said it's pretty tough to get anyone that knows much about that stuff anymore. But that's for another discussion.

Of course, the color coded cables were nice. There were some old lead cables without colored pairs. All pairs were red and white, as I recall. Those had to be toned out. Big or small pair count, those were a pain.

Jim

Roughly, how large did aerials get? The pair count found over residential streets is, likely, much smaller than the number of pairs found around commercial & industrial buildings.

The largest one I ever saw in the air was 2,700 pairs. Beyond that, it would be an eyesore, not to mention the weight of it.

I worked on 2 3600 pair paper cables recently.

The paper is much worse than the high pair count.

We labelled 100 pair super groups 1-36 with marking tape that said group 1, 2 3... 36.

Then we labelled 25 pair groups within those groups 1-4 with colored zip ties, blue orange green brown.

Some of the counts were filed within the super group! That was fun. Somewhere before our splice someone didnt keep the 25 pair groups straight and spliced the 100 pairs wild. This made pair tagging more annoying later.

Our new cables were pic. We did the far end and brought it to the paper already half tapped in. We saved time by sending our own tone through using the half tap.

So we put the new 25 preteriminated plastic 25 pair in our splicing head with a fresh module on top, then we would send tone out on the paper, just grabbing whatever pair in our group was on top. Then we would find the tone in our head, snip the paper and transfer it in.

We were getting 100 pairs done per 8 hour day, which was more like 4 hours of splicing.

I'd be reaching for the Excedrin and then some after each day of trying to sort out a cabling nightmare.

Splicing pulp cable ("paper") wild was quite common and still is. Obviously, it's not preferred, but as long as it is done the same at both ends, what difference does it make? Really nothing, unless it gets cut.and has to be spliced. Thank goodness for modular splicing systems, such as 710 and MS2, where all pairs are laid out in logical order, similar to how we use 66 blocks. It doesn't really matter which COLOR appears on a terminal, as long as it is the same on the other end.

I've got a batch of 568C patch cords to sell you! 🤣

Yes, we're used to paper being wild, of course. But this was like pair 25 showing up in the 4th group, pair 76 showing up in the first group.

Normally we would see pairs within the 25 pair group wild, which is fine. But it was a little annoying that old splicer got sloppy and let the whole 100 pair supergroup go wild.