How To Install Under Cabinet Lighting
Jul 27, 2011 | by Wendy Weinert
Discreet and subtle, under cabinet lighting is never really noticed until you need it until it becomes one of those "aha" moments that makes you glad you were smart enough to install it. With baby boomers becoming the largest senior population in history under cabinet lighting is more popular than ever. Installation is fairly quick and easy. Be sure to cut the power off at the main switch before you begin to avoid any electrical shocks as you work. Do test it with a working light first to make sure there is no juice at all.
The first step is to unscrew the wall plate disconnecting the wires from the receptacle and then removing it from the box. The box should be affixed to a wall stud that you can visually locate. Take a two-gang, old-work box and place it over the existing box so that the open side of the hole is to the unattached side of the existing box, away from the stud, take a pencil and trace all the way around it. Enlarge the hole and be certain that the cable feeding into the electrical box is loose before you remove it.
Holding your new light fixture in place, find the prescored knockout hole in back and mark the wall straight out from it. You will need to use a stud finder to make sure there is a stud between the mark and t he hole in which to place the electrical box. Using a 1/2 inch spade bit, drill through the wall just under the upper wall cabinet. Then cut a length of 12/2 non metallic electrical cable that will reach from the 1/2 inch hole you drilled to the two-gang box hole and add two more feet to it. Put one end of this cable into the 1/2 inch hole in the upper wall. Then reach through and bring the cable end through the hole for the electrical box back into the room where you are installing the light.
Holding the light fixture to the underside of the cabinet bring it forward so it is hidden against the front edge of the cabinet. Affix it with the screws that came with it and then pry the knockout plug loose from the rear of the fixture. A cable connector installed in the hole will hold the cable in place. Next strip away the plastic sheath from the end of the cable 6 inches and push the cable through the connector.
Secure the cable carefully and take care that the connector closes over the sheathing and not the wires. Placing the two-gang box next to the hole you made in the upper wall, place the end of the cable into the box. Now you can pull the end of the cable that is coming out of the light fixture into the box as well. Pushing the box into the hole, you should now press it against the wall and tighten the screws until it locks into place. You will then need to use a green pigtail connector to join the copper wires from the old and the new cable.
Finally to complete the wiring you will need to separate the remaining cable white wire and cut 2 eight inch pieces. Fasten one of them to the GFCI screw terminal that is marked as the white wire line. Then cut two more 8 inch black wires stripping off 1/2 inch of the insulation and join them to the black wire coming from the cable. Affix the loose end of one of these wires to the GFCI terminal hot wire line. Wrap the pigtail around the green grounding screw on the GFCI and leave a minimum of 4 inches exposed. Connect to dimmer switch black wire. Affix dimmer switch yellow wire to green grounding wire, and the last white wire to dimmer's white wire. Secure the GFCI and dimmer switch. Last you will need to note that inside each fixture is a white, black and green wire. These will need to be connected to the same color wires coming from the cable before you install the bulbs and place the cover on the fixture. Test your work.