Occasionally homes wired in the 70s had bundles using up to the red-blue pair giving capability of up to 6 phone lines. Sometimes these bundles of wires may be covered with an outer jacket or sheath which may be gray, brown or white. I recently found out that the reason for pulling 6 pair cables 12 wires was in hopes of selling a system that was called The "Home and Farm Interphone" which required 12 wires between sets.
This was an attempt by Ma Bell to produce an intercom system for home use using phone sets and small axillary speakers around the house. It was quite expensive so it had a limited sales market and I have been told by one phone collector that it didn't work very well. Commonly, houses that were pre-wired with this type of cable, would have the cable pulled in a loop. This simply means the installer pulled the cable out of the center of the box, folded it over, and pulled 2 cables through the walls.
When you find this kind of installation, it has the appearance of twice as many wires. Another result is the look of a rats nest when you remove an outlet plate. The reasoning behind this practice was to allow for the possibility of a broken wire in the wall. If a break occurred somewhere in the wall, the home owner wouldn't notice any thing wrong because the signal would go around through the far end of the cable and come back to the phone from the other end. About telephone wire color codes How to understand them. A complete list of color codes is available. Given that you have to be consistent between the two ends of the wire, you might as well follow the standard.
wiring standard RJ RJ telephone data cabling connector color code. T- B" They differ only in connection sequence, not in use of the various colors. When I moved, I just unhooked my piece of wire and rolled it up for my next What's described here are the color coding conventions for phone wiring, and how.
Converting a jack to Line 2 means that you will no longer be able to use it for Line 1. In practice, you'll probably want to install a second wiring block beside the first, and use a short piece of four-strand wire to extend the system from the existing block to the new one.
This way, you can have a Line 1 jack right beside the Line 2 jack. Repairpersons have sometimes remedied this by running the one phone line across the black and yellow wires rather than replacing the cabling. If this has happened, you won't be able to run a second line thru the four-strand wire. This is uncommon, but it is a gotcha to be aware of. Four-strand wire supports up to two phone lines.
Converting a jack to Line 2 means that you will no longer be able to use it for Line 1. Nowadays, Cat5 cable is commonly used instead of station wire for telephony. Warning about an annoying feature of PayPal's page not my doing: These cables will be absolutely useless for two line devices. The label "tip" is usually the positive conductor and the "ring" is usually the negative conductor. Don't be squeamish about poking around inside the Network Interface Device. There are only 10 colors to memorize in a specific order.
If you are installing three or four lines, you might also consider buying eight-strand wire. The color coding conventions for this kind of wire are as follows:.
There's also six-strand wire, which is the same as eight-strand wire with the brown pair left out. This color system actually extends up thru other colors to distinguish 25 different pairs, but even the most techno-geeky of us will probably never have that many phone lines in our homes.
If you're interested, you can get the details to this system at Phone-Man's Home Page. If you have very old existing wiring in your house, it may not follow the conventions described above, but new wiring should follow them. If you think you've got everything hooked up correctly, but one or more of your lines is "dead" no dial tone , the problem might be the local phone company's problem, or it might be in your own wiring.
Be sure that the problem isn't in your own wiring or in one of your own phones before you call the phone company to check on the problem. If they determine that the problem is on their side of the network interface device, they have to fix the problem at no charge to you; but if they determine that the problem is on your side of the network interface device, they'll charge you just for having determined this, and they'll charge you a second time if you have them make the fix in your wiring for you. So how can you tell whose problem it is? You can unplug the jack for the line in question note that doing this unplugs your whole house from the phone company's network and plug a working phone into the jack instead.
This phone is now hooked directly into the phone company's network. If the phone works properly when connected in this manner, then the problem is in your own wiring. If the phone doesn't work, either your phone is broken or there's a problem in the phone company's network. Try a second phone which you know to work, and if there still seems to be no service on the line, the problem is probably on the phone company's side of the network interface device. If you're getting static on the line, it's possible that there's a hole somewhere in the wire insulation which is letting in moisture and causing a short.
Follow the wire from the network interface device to the jack and look for holes. For example, if you've used staples to fasten the wire to the wall, check for a staple puncturing the insulation. There isn't any one right way to plan your house wiring.
Star topology potentially uses a good bit more wire, but it is easier to troubleshoot because each jack is independent of the others. Fishing the wire is probably the most time-consuming part of the whole job, so if I'm just putting in one new jack, I'd usually rather just jump off of an existing jack than take the time to run a whole new wire all the way from the basement to the second floor.
However, if the house has old, premodern wiring, the advantage to running a whole new wire is that I know exactly what I'm dealing with. This section doesn't attempt to cover all the gadgets and parts related to phone wiring. For the wiring jobs described above, you usually only need to buy wire and modular jacks.
Two gotchas when buying modular jacks. You may find that wires with both color schemes have been used in your installation. Use the table below to translate between the two schemes. I strip about 1" of jacket off, then separate the wires in order, pinching firmly between thumb and finger, while bending back and forth and mashing.
There are two wiring standards for these cables, called "TA" and TB" They differ only in connection sequence, not in use of the various colors. The illustration shown is for TB. The other two pairs, Brown and Blue, can be used for a second Ethernet line or for phone connections. Note that the Blue pair is on the center pins and conveniently corresponds to the Red and Green pair in a normal phone line. The connections shown are specifically for an RJ45 plug the thing on the end of the wire.
The wall jack may be wired in a different sequence because the wires are actually crossed inside the jack.