How to Wire a Telephone Socket

Typical phone jack wiring

Home telephone wiring has been standardized to a four-wire system that uses RJ-110 cable to send an oscillating, breaking current that relays information. These wires are colored to indicate their function. Wiring a wall telephone socket should take the average homeowner about 20 minutes.

Things You'll Need

• Flathead screwdriver
• Phillips-head screwdriver
• Wire stripping tool

Instructions

Wiring a home telephone jack

1. Unscrew and remove the old telephone jack, if applicable. A new telephone jack location will require a connection to the outside telephone lines, which may necessitate installation of new RJ-110 cabling in the wall. Once this cable is available, there should be an opening that can accommodate the jack plate cut into the wall.

2. Locate the red, black, green, and yellow wires in the cable, and strip them to 1 inch of exposed core each. The telephone line works in pairs, and this pairing works in a "positive-negative" manner. One telephone line requires one pair of wires to operate. These four wires are paired as "red-green" and "yellow-black," with each pair representing a telephone line.

3. Connect the colored, stripped wires to their counterparts on the back of the jack, which are also color coded. There is a "primary" line with red and green contact wires, and a "secondary" connection with the relative yellow and black wires. The contact screws can be loosened slightly to accept a curled wire and then re-tightened. If the jack does not have colored wires to connect the contact points to the socket pins, then there will be words ("RED," for instance) to designate the correct connections.

4. Test the connection by connecting the jack to a working telephone and opening the line. If the service is connected, there should be a dial tone for the line selected.

5. Screw the telephone socket plate to the opening in the wall. Some types of plates or building codes require "plate boxes" to contain the wire contacts and prevent them from touching the home's insulation. Two flathead screws are screwed into the top and bottom of the plate, which can be directly driven into the wall material or used with a mount harness (to allow service entry without repetitive removal damaging the wall).

Tips & Warnings

• Some ancient systems use numbered contact points rather than colored wiring standards.

• Do not touch the exposed cores to each other or to a metallic surface.

References

• Residential Telephone Wiring Basics