Jack Connections for Two Lines

Underlined Italics = a future hot link to additional information
You can mix and match the way you connect your wiring at different locations depending on your requirements. For wall jacks, such as those found in most kitchens, you will want to use the first method shown below. This puts both lines on one jack, to permit use of a two line phone if desired. If you want to be able to limit which lines can be accessed at a particular location, such as to provide a teen-ager access to only line 2 in their bedroom, you'll want to use a variant of the second method. For most of your jack locations, I recommend use of the third method. This method will let you use either your existing single line sets or special two-line sets. This option also provides you with great flexibility by permitting access to either line as "line 1" on pins 4 and 5 of a jack. This provides for connection of a single line device such as a fax machine or modem to either line without use of adapter plugs.

You have several options on how to connect your jacks for two lines:

Line 1 and Line 2 on one jack (easiest way to use "two-line" phones and may use of existing jacks with adapters)
Line 1 and Line 2 on separate jacks (easiest way to use your existing single line phones)
Both of the above (this is what I recommend - provides the most flexibility without using expensive adapter plugs)

The back of most screw terminal jacks are marked with letters indicating the color of the wire to connect to the terminal and have wires from the terminal to the actual jack. On some of the diagrams below, I've left the wires from the screw terminals to the actual jacks off the diagram for clarity. Leave them on the screw terminals that match the markings.

Connecting Lines on One Jack

Connecting your jacks in this manner may allow use of existing jacks. You may even find that your jacks are already connected in this manner. However, you should check to ensure that the black and yellow pair is connected for line two. I'll show the connections for screw terminal jacks.

This is the most simple connection. To connect both lines on one jack, simply connect the wires from your cable to the matching screw terminal. To use line two with a single phone or other single line device on a jack wired in this manner, you'll need to use an A/B Splitter Adapter.

Connecting Lines on Separate Jacks

Connecting your jacks in this manner will require that you use faceplates with two jacks, unless you only want one line to appear at a particular location. I'll show screw terminal jacks connections.

To connect line one to the top jack, connect the green wire on the screw terminal marked for green and the red wire on the screw terminal marked for red. To connect line two to the bottom jack, connect the black wire on the screw terminal marked for green and the yellow wire on the screw terminal marked for red. If you want only one line to appear on a single jack, simply connect the pair for that line to the screw terminals marked for green and red. Use a small piece of electrician's tape to insulate the exposed copper on the wires of the other pair so that they do not short to each other or to something else.

Connecting Both Lines on Two Jacks

Connecting your jacks in this manner will require that you use faceplates with two jacks. I'll show both screw terminal jacks now. I'll add a diagram for 110-punch jacks at some point in the future.

To connect your jacks in this manner, first remove about six inches of cover from the end of the cable. About four inches from the end of each wire, remove about a half inch of insulation. This gap in the insulation is looped around the screw terminals on the top jack. Connect the loop on each wire to the matching screw terminal of the top jack.

Now connect the end of the wires to the bottom jack as follows: black wire to the screw terminal marked for green, yellow wire to the screw terminal marked for red, green wire to the screw terminal marked for black, and red wire to the screw terminal marked for yellow.

A "two-line" phone connected to the top jack will be connected to both lines. A two-line device would also be connected to both lines on the bottom jack, but "line appearances" would be reversed.

A single line device connected to the top jack will be connected to line one. On the bottom jack it will be connected to line two.