Gone are the days when the phone company would not only provide the telephone service, but install the phone wiring as well. Nowadays, this task is either done by paying the phone company or an electrician.
Not many people consider installing their telephone wiring themselves. Most people have the misconception that this task is an impossible feat for an average nontechnical person. Not many realize that the task is simple, safe, and does not require much technical know-how.
Complying with the Standard
It is best to determine the telephone wiring standard that is in use when installing additional wiring to an existing facility and follow that standard. When installing telephone wiring in a new building or home, however, the EIA/TIA T586A is the standard that is implemented.
Telephone Service Lines
The telephone line from the local telephone company reaches a home in two ways:
- Above ground wiring
- Underground wiring
Phone service wire pairs are distributed via telephone poles using an aerial method of connection. Attached to the pole is a breakout box which has the main service lines for the area entering in one side and residential lines running out on the other. Each of these residential lines runs to a house in the neighborhood.
Break-out boxes are set up in geographically logical points within the neighborhood before the building of houses began. Lines are then trenched back to the primary distribution can and to each house that is to be built. The wiring may need to be extended to reach the house once it has been built.
Residential Network Interface Device (NID)
The telephone wires installed within the neighborhood ends at a network interface device (NID) when connecting to each residence. The NID looks like an 8-inch wide and 12-inch long gray or tan box that features a door covering the customer and the telephone company compartments. The customer compartment can be accessed when checking for a dial tone, wiring connections inside the NID, and to trace lines that are coming out of the NID into the house.
Most telephone wires are one or more twisted pairs of copper wires, the most common of which is the 4-strand or two twisted pairs of copper wires. The first pair is made up of red and green wires, whilst the other is made up of yellow and black wires. This type of wire can carry two separate phone lines as one telephone needs only two wires. Telephone wires come in 22-gauge and 24-gauge, with the latter being the standard.
There are two types of most commonly used modular plugs:
This is the more common modular plug. It uses only two of the wires in a 4 strand wire. It is the connector used to plug the telephone into the wall and carries only one telephone line.
This plug uses 4 wires which make it ideal for handling two telephone lines.
Installing a Two-Line Wiring
In this procedure, the star or the homerun method will be used for the installation.
- Connect the tip wire (electrically positive wire) of the plain old telephone service line (POTS) to the tip wire of the jack. Do the same for the ring wire. There are a few possible combinations of colors for each pair. However, the most common pairs are composed of red/green and yellow/black. The former pair is used most of the time, wherein the red wire is the ring and the green wire is the tip.
- Run two or more lines within one wire in order to reduce the work and materials. At the end of the wire, break out the two lines using an adaptor. This allows line 1 to be connected to an RJ-11plug, and line 2 to another RJ-11 plug.
- For a small PBX or phone system, the POTS line (or trunk lines) is usually connected to the system Via RJ-11 plugs.
- NID’s terminating with modular jacks only requires the phone system to be connected wit RJ-11 plugs.
- NID’s with a terminal strip, or an area where the wire pairs that comprise each POTS line stop at an intersection, wherein the colored wires can be joined directly. The lines should be either directly connected to the PBX, or a modular jack should be connected to each of the POTS lines on the strip. The same procedure for connecting the POTS lines to phone jacks should be followed.