Installing dimmer switch

A standard single-pole dimmers 2-way or three-way dimmers. With a standard 2-way dimmer, a single switch controls a single light. With a three-way dimmer, you can control a light from 2 different locations. This lets you dim from one location and turn the lights on and off from another. When installing a Dimmer switch, all you're really doing is controlling the amount of voltage flow to a light which makes it dim at a low setting to a fully bright light at maximum setting.

See my Romex Cable page to get familiar with the different types of wire The cable consist of a black wire, a white wire and a bare copper wire.

This simple diagram below will give you a better understanding of what this circuit is accomplishing. Now in the diagram above, The power source is coming in from the left. Notice the black wire is the only wire that we are controlling through the 2-way switch. You have an incoming hot wire black going to one screw it does not matter if you use the brass or silver screw on the side of the 2-way switch and a black wire from the other screw on the 2-way switch going to the load light, ceiling fan etc..

The white wires are wire nutted together so they can continue the circuit. Now as for the ground wire. It is very important to connect the ground wire to the switch as well. Either loosen the screws or use the wire strippers to snip the ends off and remove the old switch. As always, green denotes the ground or copper wire. Unlike installing a light fixture , both wires going to the dimmer will be black and usually can be placed on either gold screw.

If the switch can be used for either a single-pole or three-way, there may be an extra screw so make sure to look at the wiring diagram. So looping it is! Once the wires are attached, you will want to re-fasten the switch to the electrical box with two screws top and bottom, and then re-attach the switch plate.

Turn the breaker back on, and there you have it… ultimate control over the brightness in one small section of the universe! Disclosure: BobVila. You agree that BobVila. All rights reserved. Expert advice from Bob Vila, the most trusted name in home improvement, home remodeling, home repair, and DIY. Find trusted local pros for any home project.