Installing a Dimmer Switch in Your Home

Adding a dimmer switch to your home lighting is a great idea for several reasons. They conserve energy; they add beauty to your room environment; and they save you money.

Before installing however, it's best to determine the wattage of the load on the circuit you wish to place the dimmer switch. This is important as an overloaded dimmer switch (which is actually an electrical rheostat) will overheat and could become a fire hazard. Another word of advice before purchasing is to know that most dimmer switches can only be used on single-pole switched circuits (not designed to operate a fixture from more than one location). Also, dimmer switches cannot be used with fluorescent light fixtures or CFL bulbs.

Having said that, let's begin. The first step is to determine which of your fuses and/or circuit breakers control the circuit that you wish to install your dimmer switch on and to make certain that the fuse has been removed or that the circuit breaker has been turned off.

Once that has been done, you can removing the existing single-pole switch. A common tip (flathead) screwdriver is typically used to remove the two switch-plate screws. Having done this, depending on the wall surface (i.e. paint, wallpaper, etc), carefully remove the switch-plate cover.

Depending on the screw heads anchoring the switch to the switch box, it may require a Phillips-Head screwdriver to remove the switch.

Now that the screws have been removed, there should be a small degree of slack in the wires allowing you to pull the switch out toward you a couple of inches or so. Remove the wires from the switch and examine the wire tips. If they were fed straight into the back of the switch (many 14-gauge wire circuits are fastened in this manner), you can depress the wire and twist to remove. These wire tips should be in good condition and not in need of snipping. If the tips were formed in a circular fashion around the switch screws, then it is best to cut these circular tips off at the insulation and restrip to approximately ½ inch.

Having removed the new dimmer switch from its packaging, it is time to install. Dimmer switches are generally deeper and thicker than a common single-pole switch. Therefore, if the box receptacle is not deep enough to accommodate the new switch, it should be replaced.

Most new dimmer switch wiring is pre-trimmed and only needs to have the insulation ends removed. This is a task that you can do with your fingers. If your switch circuit has a bare copper grounding wire, the green pigtail from the new switch will be connected to that grounding wire. If your switch was not grounded, then this wire can be capped or taped with a UL approved brand of electrical tape.

Polarity is not an issue with dimmer switches. This is noted by the usual black wires connected to it. Even if you have a white neutral and a black hot wire in your switch box, you may connect each of the two black wires to these lines without consequence.

Most new dimmer switches provide wire nuts suitable for wire connections. Begin these connections by twisting the wires in a clockwise direction for a turn or two. Many home circuits have solid copper conductors while virtually all dimmer switches provide stranded wire. In this case place the stranded dimmer switch wire into the wire nut, and then place the wire nut over the tip of the solid copper conductor. Once this is accomplished, you'll be ready to reverse the process above and begin installation.

Note: Double-check your wire tip connections for integrity and apply suitable (UL approved) electrical tape wound in a clockwise direction over the wire nut and down over the electrical wires.

Carefully tuck dimmer switch into receptacle and install anchor screws. Dimmer switch plate flange should be flush against wall surface.

Switch plate can then be attached and dimmer switch knob installed.

Restore electrical power by reinstalling fuse or switching circuit breaker back to its on position.

Let there be adjustable light!