2torial #0877:
Learn2 Install a Second Phone Line (continued)

Check the NID connections

The NID usually has two covers: one for the outside line (marked "telephone company access only") and one for the inside line (marked "customer access"). Everything you need to be concerned with is in the customer access side of the NID.

Open the NID. Inside the customer access side of the NID, you'll see one or more phone jacks just like the square holes on your phone and your wall jacks. The outside line, which enters from the phone company's side of the NID, should be plugged into one of them. Colored wires run between these "test jacks" and pairs of terminals, which are color coded green and red (and sometimes black and yellow). The terminals usually look like metal screws or nuts.

The line that goes to your wall jacks is also connected to these terminals. This line is an insulated cable containing four to eight smaller copper wires, each insulated in different colored sheathing. These wires emerge from within the larger cable sheathing inside your NID. If you have one active phone line, at least two of these wires will be connected to two of the terminals: the tip (T) wire to a green terminal and the ring (R) wire to a red terminal.

What the colors mean. Different colors of insulated sheathing are used to differentiate between the pairs of wires. There are two standard color systems used in most residential wiring. In a four-wire cable (which is standard to many single-family homes), the first pair is green (T1) and red (R1), and the second pair is black (T2) and yellow (R2). If this is what you have, the black and yellow wires will carry your second line. (Six-wire line may also use these colors, with a third pair colored blue [T3] and white [R3].)

In most cable with more than two pairs of wire, two-color insulation is used. You probably won't encounter a cable with more than four pairs (eight wires). These wires have stripes of white and another color: blue (line 1), orange (line 2), green (line 3), and brown (line 4). The tip line is white with stripes of the second color, while the ring line is the second color with stripes of white. So in this scheme, T1=white/blue, R1=blue/white; T2=white/orange; R2=orange/white; and so on.

Connect the T2 and R2 wires. If your T2 and R2 wires are not already attached to their terminals, attach them to the unused pair.

First, disconnect the outside wires from the test jacks in the NID by removing the plugs from the test jacks (just like unplugging a phone). Using your wire stripper, remove about 3/4 inch (2 centimeters) of sheathing from the T2 and R2 wires, exposing the copper. Loosen the T2 and R2 terminals with a screwdriver or wrench and wind the ends of each wire once or twice around its terminal shaft, right below the top of the terminal. If there are metal washers on the terminal shaft, attach the wire between two of them. Remember to attach the T2 wire to the green (or black) terminal, and the R2 wire to the red (or yellow) terminal. Gently tighten the terminals, being careful not to damage the wires.

Plug the outside wires back into the test jacks, fold the wires into the NID, and close it.

Note: If your NID has two pairs of terminals, you should attach the T2 and R2 wires to the unused pair. But there may be more than two pairs. If they aren't labeled clearly with the phone numbers they serve, ask the phone company technician to label them for you when he or she comes out to activate the new line.