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Joined: Jul 2002
Posts: 8,443
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Trumpy Offline OP
Member
I recently hooked up a 630mm2 Al 3 Phase+ Neutral, it took ages, this is the largest
multicore over here.
What is the largest cable you have ever installed?.
Your input please-

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That's a hefty cable! I seldom deal with anything much above 25 sq. mm in my local domestic wiring, although I've used much larger cables in the past on low-voltage telephone equipment.

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Trumpy Offline OP
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Oh, it was terrible, Paul, with these sizes of cable, you have to use Hydraulic Crimpers,
you must bend the wires, as little as possible, even Heatshrinking the wires(?!), was an act in itself.
Thank God, I don't do this type of work much,
as it bucketed down, the whole time that I was doing this, I got absolutely drenched. [Linked Image]
Mind you Paul, I take my hat off, well and truly, to you Telecoms guys, who can sort out a 400pair cable,with ease, now that is
being a professional!. [Linked Image]

[This message has been edited by Trumpy (edited 12-16-2002).]

Joined: Nov 2000
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Trumpy,
Why so big of cable? Wouldn't a parallel installation be more cost effective. That size would be a little bit larger than our 900 kcmil (606mm2) We often look at paralleling when our wire size starts exceeding 500 kcmil (336mm2).
Don


Don(resqcapt19)
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Quote
who can sort out a 400pair cable,with ease,
It's all wiring, but it's a very different type of work when dealing with many small-gauge wires.

There's no big secret to sorting them out, except to be methodical. A photographic memory for the color coding helps too, so that you know instantly that, say, the 10th pair will be red/slate.

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Trumpy Offline OP
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Resqcapt19,
It is not looked upon over here(NZ), as good
practice, to parallel up cables, especially where these are laid underground.
This cable was taken straight out of a 22kV/400V Xformer, to supply a new building in the local Meat processing plant, via a new switchboard and Metering.
Another reason for the single cable, was that our Pan Assembly, only allowed single
compression lugs, without the risk of Flash-over and other problems.
Paul, nice to see that you can commit all of them colour-codes to memory, thankfully, with all of the phone work, I have ever done, has only depended on a few colours.
These new Cat5 wires are good, we have a standard code for how these are to be connected, so you cannot really muck it up. [Linked Image]

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The colors you see in CAT5 wiring or the 4-way station cable commonly used for internal phone wiring these days do actually use the first few color pairs of the larger overall system.

It's not really that difficult to learn. There are two sets of base colors for each side of the line, viz.:

Tip: white, red, black, yellow, violet
Ring: blue, orange, green, brown, slate

If you can memorize those two sequences, you can work out the colors for any pair quite easily.

The first five pairs use white as the base tip color with each of the ring colors in turn, thus pair #1 is white/blue (tip) and blue/white (ring), pair #2 is white/orange (tip) and orange/white (ring) etc.

For the next five pairs, you just repeat the sequence but with red in place of white. The next five then all have black as the base tip color, and so on. By the time you've worked with it a while, you just mentally "look up" the color for a given pair without having to count the colors.

For larger cables, the wires are bundled into groups of 25 pairs each and each bundle is individually identified.

A particular line may well run through several different pairs on its way to somebody's house. For example, it might come out of the CO building on a black/green pair, then go from a main distribution point to a smaller cabinet on a red/blue pair, then from there to a pole junction box as a white/brown pair. That's why the records of lines are so important!

The older-style phone cables used solid colors instead of the banded insulation found today. Pair #1 consisted of just a plain white wire (tip) and a plain blue wire (ring) twisted together. #2 would then be white and orange, and so on. So in say a 10-pair cable you'd actually have 2 blue wires, 2 orange, 2 green, 2 brown, 2 slate, 5 white, and 5 red. You try not to untwist the pairs, otherwise you're in for some real fun...... [Linked Image]



[This message has been edited by pauluk (edited 12-17-2002).]


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