CENTRALIZED KEY TELEPHONE INSTALLATIONS

[Music] my name is Dave Russell I'm an AT&T engineer and I've been working with the Bell Telephone Laboratories to find better ways to install Key Systems today we're going to talk about centralized key telephone installations by installations we mean that we have three main elements space equipment and effort space is in the form of conduits and Raceway systems and closets wall space in the closets equipment in the form of backboards Connecting Blocks and apparatus mountings effort of course is your effort to install the key telephone systems themselves we traveled for several years in your companies and listened to you we saw many installations I would like to show you one such installation this is a closet in one of the companies which did not have enough room to terminate all the station cables on Connecting Blocks it's a condition we got to call horsetails horse tails are these dangling cable fairs from the station cables this is a condition created by stripping the sheath from the station cable and allowing the 25 pairs of each cable to dangle together in a mess such as you see here an installer or repairman would have to pick his pair out of this bundle if he wishes to terminate any particular pair it's from installations like this that we learned many things we learned that no one likes horse tals space is a problem and we saw some devices locally designed such as standoff brackets and designation strips we found that everyone wants standardization however standardization is just another word for organization people want an organized approach to their job pre-plan closets we found were most desirable let's sneak a Peak at a new approach this is a cross connecting Arrangement as you see it here it would take about half the space of our present methods of terminating wires and cables the closet you're looking at is 6t 10t rather by 6t it accommodates 100 lines and 160 stations it consists of modular backboards each of these being a module and it has considerable growth potential it is divided into four areas in this closet we have a place for everything it's aimed at your convenience the modular backboards come in four colors green blue red and yellow each color identifies an area see and PBX station key and auxiliary Services let's take a look at a schematic representing these areas in the lower left we have here the green area for Co and PBX terminations to the right of that and lower right is blue for stations at the upper right is red for key features and at the upper left last but not least is yellow for auxiliary services such as 6A dial intercoms or 1 A1 diode matrixes this plan includes seven new items of Hardware four backboards a new connecting block a standoff bracket and a designation strip let's take a look at some of the new hardware involved this is the 66 m150 connecting block it is a new block and as you can see is smaller than the block is a 50 pair block 25 pairs on one side and 25 pairs on the other side it's what we call a 2X two block these two lugs are multipled together and these two lugs are multipled together this particular lug would be for your cable Fair this one for your jumper similarly on this side this would be for another cable pair and this one would be for a separate jumper with this connecting block we have a new designation strip which is a Snap-On type of designation strip these strips come assembled to the Fanning strips of the blocks one strip on each side of the block we also have an 889b bracket you'll recall that we I said we saw attempts to make stand off bracket field this is the 89b bracket it provides a place for cabling in the wiring Channel behind the connecting block when the connecting Block's in place it has openings in the sides through which you may bring your cables so that you may terminate them in the proper locations on the connecting block snaps on in that fashion now we've taken the 89b brackets and assembled them into modular backboard forms let's take a look at one of the modular backboards this is the 183 A2 backboard it's 8 1/2 in wide and 20 in long it's green and it is for the co PB X pairs the outside plant pairs as you see it's equipped with four 889b brackets and will accommodate 200 pairs of Riser cable or outside plant cable of other types and as we said has the Snap-on bracket attached to it so that you can snap on your 66 m150 connecting block over here we we have the full module blue backboard it is the 183 B1 backboard it's 17 in wide by 20 in long it has 8 889b brackets assembled to it which will accommodate 8 66 m150 Connecting Blocks you can see two cables we have placed in the wiring channels it would go behind the block when snapped into place the cables have been brought out through the side wiring Channel and when we snap a block in place you see we have our pairs available for terminating down the side of the block on each particular side the third backboard I'd like to show you is the one for the key features this is the red board as I said for key features it is a full module board 17 in by 20 in it comes equipped with four 66 b425 Connecting Blocks that's presently our standard connecting block and it has Distributing Wings wire Distributing Rings assembled to it these are mushroom shaped as you can see providing a wiring Channel this represents an equipment cable running between the Matched blocks and would be terminated on the cable lugs of the block the remaining five lugs would be used for jumpers as you notice this also has the designation strip with it and comes equipped from the factory with the designation strip we have the open wiring channel for the jumpers running down here and across the bottom now let's take a look at the fourth backboard this is the 185 A1 backboard this particular board is the yellow board for auxiliary services such as terminations for 6A dial intercom or 1 A1 diode matrixes or whatever is appropriate for the particular installation as you notice this comes equipped with the mushroom Distributing Rings giving you an open channel for jumpers now you will recall that the backboards are used in a definite pattern the location of the first backboard is critical engineering generally will establish this location and your construction man will usually be the first to be in to locate the backboard at placing it let's review the pattern on the lower left we have the green backboards for Co and PBX to the right of these we have the blue for stations Above This the red for key features and to the left and above the yellow for auxiliary Services now let's see how we would build up an apparatus closet now what I mean by an apparatus closet is this is a closet by definition in which you would place your apparatus such as your 1 182 key equipment in the apparatus closet we have in the lower left construction man would place the green backboard in this particular case we have chosen to place two green backboards one above the other this would accommodate 400 pairs of riser cable next the installer might come into this closet and place the blue modules the he is placing these boards with four screws each to mount eight Connecting Blocks which has the capacity for 16 stations on one of these modules remember you we would never multiple in this particular field all cables would be terminated permanently when placed next he would place the red backboards these are your key feature backboards this is the location where you would expect to multiple your stations to your lines as I say lastly he would place the yellow for your auxiliary services in this fashion he would build up the apparatus closet the satellite closet and the satellite closet is one which would slave off of the apparatus closet but would not contain apparatus would be built up in this pattern the blue on the bottom and the red on top this could be a larger or smaller closet than shown here the red is merely an extension of the key features and the blue is the place for terminating the station cables now between the apparatus closet and the satellite closet we have tie cable let's show you how the tie cable would be run the tie cable would be run from Blue to red blue of the apparatus closet to Red of the satellite location because as you recall in the app in the apparatus closet the tie cable is an extension of the station whereas in the satellite closet the tie cable is the extension of the key features let's take a look at how you might run a jumper coming into an apparatus closet we will assume that the station cables have been terminated that the outside plant cables have been terminated that the equipment cables have been terminated and we have nothing but to run jumpers to activate a line first you would pick up your central office pair and find your Line run a pair jumper up through the the wiring channel to the red area find the tippen ring input to your key system and terminate the jumper immediately below this you would pick up your key feature terminations there are eight pairs below this three of which have your line and control leads you would take the three pair F cross connect wire run it from the red down across your channels down into the blue to the appropriate station termination we have not as yet run our ring leads we did not do this because half the time you have common audible system so we would take a pair jumper picking up the ring leads take it out through the wiring channel to the yellow terminate it on something such as the 1 A1 diode Matrix bring a pair jumper back and over and down into the station area this would then have completed an installation in the apparatus closet if we were to run an installation to the satellite closet where a station is working from the blue area of the satellite location we then would run our central office jumper picking up our key features then run down to the tie Cable location in the blue remember the tie cable is now the extension of the station in this closet we would then go to the satellite location pick up our key feature in the red area and jumper it to the station termination in the blue to summarize this particular closet arrangement we feel will save considerable space it saves about half the space that we presently use it will reduce the amount of effort required for you to plan and install a closet it presents to you an organized method there's one thing I'd like to say about standardization we can tell you a method for standardization but we cannot standardize for you standardization is in your hands now section 518 300100 explains everything that I have told you today plus has additional fact uh one more word before closing uh we're working on improvements improvements to the techniques that you have seen today meanwhile we know that you will find the new Arrangement helpful