custom wiring scheme

[Babybearjs]

well, as I have said before, I scrapped the 25 Pair cables on my phones and went with individual RJ45 cords which I spaded out and connected... on my W.E. 444's I have 2 cords, and on my 464/564/2564's I have 3, which may go to 4 if need be. enclosed if a copy of the pinout... you'll notice that I wired it differently from what it was wired traditionally. the reason being, to send all the spare wires to the end of the line so it makes it easier to trace and because of the cabling. enclosed is a copy of how my phones are wired.... on the right shows the individual colored cords... blue, orange, green, brown and gray. these refer to the individual keystone jacks at each location. I used the same color cords at my KTS the only problem was brown, there is no brown keystone jacks, so I had to go with black... My brown and gray cables are for buzzers and buttons and are not assigned at present...

[poplar1]

Even though the 400 series keysets had only one lamp ground, this was corrected with the 500 series keysets.

The 565s and 2565s have a full pair for each lamp--LG and L.

The 564s, and 2564s have only one White-Green lead for lamp ground inside the set, and all 5 lamp grounds are strapped together inside the set. However, in the amphenol plug on the mounting cord, the pins corresponding to all 5 lamp grounds other are strapped together. The single white-green mounting cord lead to the set is only a few feet long, so there is little loss there; but by the time it reaches the 25-pair cable connector, it has 5 paths (White-Green lead, Red-Blue lead, Red-Brown lead, Black-Orange lead, and Black-Slate lead) back to the KSU so it can carry 5 times the current.

The single lamp ground lead in your two feeder cables will not carry enough current for lamps on 19 sets without making them dim.

[Babybearjs]

well, even you know there is a common buss on the lamps in each phone, the brass strap that connects all the lamp grounds together... If your sets don't have it, then that would explain that situation. ITT phones always had them, unless it was removed by the installer or never added from the factory. currently, I'm having no problem with the lamp circuit. this frees up 6 wires to start with...  I do have a W.E.2564 and had to make a common buss for the lights. but my wiring scheme does work so I'm happy with it... even though I replaced the RJ61 cord with 3 RJ45 cords is a personal decision..... the parts for the 25 pair cable are expensive and hard to find... getting a 100ft. cut of Cat5E 25 pair cable @ 0.40/ft. is pretty good figuring it averages about $0.86/ft. and to be able to intergrate my LAN connections onto my cable runs make it easier to wire as well as cleaner...

[poplar1]

Yes, I mentioned that the LGs (lamp grounds) are strapped together inside the 564. That's the bus you are referring to.

However, even though the actual lamp ground leads for lines 2 through 5 are not in the original 30- or 34-conductor mounting cord, still, those pins are strapped in the plug of the mounting cord:

"Terminals 28, 31, 34, 37, and 40 are strapped on the mounting cord connector."

This is Note f on Table III, page 190 of the 1968 ITT manual:
http://www.strombergcarlsontelephone.com/kellogg/PDF/1977_MANU_TIMM-2.pdf

When you connect an ITT 564 with the original plug-ended 34-conductor cord, this connects the following wires together in the cable coming from the key system:
28 (WHT-GRN), 31 (RED-BLU), 34 (RED-BRN), 37 (BLK-GRN), and 40 (BLK-SLT).
Thus the white-green stranded lead inside the set is carrying the current from all five of these solid copper leads, not just the one white-green that you see going to the bus inside the phone.

So even though you see only one lamp ground lead (white-green)in the original 34-conductor mounting cord and inside the phone, still, up to the  amphenol connector on the 25-pair cable from the KSU there would be lamp grounds for each line, thus capable of carrying up to 5 times as much current as a single conductor all the way from the KSU to the phone.

Each 51A lamp draws approx. 40 MA.
One 24-gauge wire is rated for how many amps?

Distance is another factor for voltage drops.

[Babybearjs]

the distance from the KTU to the end of the line is less then 50 feet, so I'm not worried about that.... plus how many lights are going to be on at any one time....less then 6.... since I only have 5 extensions running right now, and one of them is the patio phone which is seasonal.... only in use during good weather...if I leave it outside in the rain.... it shorts out the KTU and the station lights stay on until I unplug the phone....