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66 Blocks: Punching two wires onto the same terminal? 3

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snd1234

IS-IT--Management
Mar 10, 2006
123
US
I have an 66 block (M1 type) with the RJ21X connector on the right side.

66 Block Pic:
I want to terminate a 25pr cable to the block on the side with the RJ21X. The wires that feed the RJ21X connector are already on those terminals. Is it OK (and a good idea) to terminate over the top of these?

I want to use the RJ21 connector for easy troubleshooting to a breakout panel.
 
Your wiring methodology is not standard, but that aside, you should never double punch on a 66 block. The mechanical connection is designed to work with a single solid wire. Multiple punches deform the notch and one or both leads will develop oxidation and flaking connection problems. The geometry of the notch is to allow for just enough insulation displacement to make a gas tight and electrically sound mechanical connection of one wire. If you absolutely insist on using the same blocks posts, then use something like this:

It can be a bit clumsy, but it is the only way to get certifiable connections on the block is you want two leads on each post.

You may want to look at a different block so you do not have to wire it with two leads per post.
 
misseditbythatmuch said:
but that aside, you should never double punch on a 66 block.

This is the important part. Double punch may work for a short time, or for a long time. In the end, it often ends in tears. Don't do it.
 
OK, that's what I needed to hear.

What do you think about punching down the 25pr cable to the 3rd column of posts and then putting the bridge clips on top?

Also a bad idea?
 
Yup, remove the bridge clips, punch your 25-pair on the 3rd column, then put the clips back on. The amphenol is still good, using the 4th column, and your 25 is good to go.
 
Why wouldn't you punchdown on row 1 and use bridge clips across 2 and 3?

jeff moss
 
Wow 66 Blocks :) I am still surprised to hear that a modern country uses 1962 technology. That is like trying to go to space with Apollo 13, it may work but you may call for Houston with a problem.
Use Krone, BIX, Siemens or any other new connector block and avoid getting shocked with a sweaty forearm.
But aside from that I have to agree with the above that double punch is a no no.


Joe W.

FHandw, ACSS (SME)


"This is the end of the world, make sure to buy your T-shirt before it is too late"
Original expression of my daughter
 
Jeff,

Because some else will be punched down on row 1.
 
Can you post a picture of how your block is wired/set up?

jeff moss
 
Correct me if I'm wrong, but this block looks like the ones that were used by Telcos in the 80's for demarcation of the trunks (in Canada anyway). There are 4 rows of pins with an amphenol connector on both sides of the block (one for the Telco side and for the PBX). the 4 rows of pins are split down the centre. Rows 1 and 2 are connected to each other and rows 3 and 4 to each other. The intent was to put bridging clips on the pins between rows 2 and 3 to provide continuity for the trunks. It was used to isolate the trunk from the pbx for troubleshooting.

If you want, you can punch down another cable on row 2 which will physically connect you to the cable connected to the amphenol on that side of the block or to row 3 for the connector on the other side.

Or you can use the bridge clips to effectively splice the two cables together.

 
An RJ-21X block had only the amphenol connector on the right hand side, punched down to column 4. The telephone company would run single pair jumpers from binding posts on the building entrance terminal to the left hand side of the block, on the first column. The 2nd and 3rd columns are intended for the bridge clip to connect to left side to the right side. Removing the clip allows you to test each side separately in case of trouble. Punching anything down on the 2nd column bypasses that ability, and connect directly to the telephone company side of the demarc. If we decided not to use the amphenol connector, but use a piece of 25-pair cable, or even just jumpers to another block, that would go on the 3rd column, so that it was still on the customer side of the demarc.
 
Back when I started out installing switched access dialers, I wss told to avoid punching down anything onto columns 2 and 3 of RJ-21x blocks when possible. Supposedly the LEC could disconnect the wires to the 31x jacks without notice and jumper from column one to column 4.

I [love2] "FEATURE 00"
 
Yes we only used those blocks for Demarking the lines. Putting two wires on a single pin is only a source of trouble. If you want to have two jumper wires to come off a pin just loop it and don't use your cutting blade on punch down tool use the puchdown without the cutting blade.
 
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