Dimmer Switches

Useful Tips on Using Dimmer Switches

By Mark J. Donovan




Dimmer Switches are excellent for setting the mood in a dining room or home theater. They are also easy to install. However there are a few things to consider before going out and buying a Dimmer Switch.

Types of Bulbs that can be used with Dimmer Switches

First, dimmer switches are only meant to work with 120V incandescent bulbs and halogen bulbs. They are not meant to be used with fluorescent bulbs and most compact fluorescent bulbs.

The reason for this is that dimmer switches are meant to work with bulbs with wire filaments, which 120V incandescent and halogen bulbs have. Fluorescent bulbs and compact fluorescent bulbs, on the other hand contain a gas that requires a certain amount of voltage to operate the light. Consequently they should not be used with a dimmer switch. For low voltage halogen bulbs a special dimmer switch should be used.

Type of Dimmer Switch (Single Pole or 3-WAY)

Second, there are single pole and 3-way dimmer switches. Make sure you pick the right one for your application. If the light can only be turned on via one switch then you need a single pole dimmer switch. If the light can be turned on by two switches then you need a 3-way dimmer switch. Note that in a 3-way lighting application only one of the switches can be a dimmer switch.

Dimmer Switches Save Energy

Old dimmer switch technology worked on the principal of controlling the voltage to the light fixture. As the dimmer switch was turned up or down, the voltage supplied to the light fixture was correspondingly elevated up or down. This type of dimmer switch utilized a rheostat to vary the voltage to the light and was highly energy inefficient.

Today’s dimmer switches, on the other hand, operate using a TRIAC which effectively switches the power on and off to the light bulb at a high frequency. The rate of switching is so fast that you can not discern the bulb is ever off. However, it is this function that controls the dimming function in today’s modern dimmer switches.

Due to the fact that the light is turned off a portion of the time with these TRIAC based dimmer switches, dramatic energy savings are realized. In addition, the life of the light bulb is also significantly extended. For example, if the bulb is dimmed to 50% of its output, it will save roughly 40% in energy costs, and can extend the life of the bulb up to 5-20 times, depending upon the bulb type.

Dimmer Switches Get Hot

If you feel the cover plate on a dimmer switch you will notice that it can get rather warm. This is normal. Solid state dimmer switches are about 98% efficient. The remaining 2% of power is converted to heat, and is dissipated towards the front metal plate of the dimmer switch.

Installing a dimmer switch

As long as the lighting load is rated at no more than 90% of the wattage rating of the dimmer switch there is no reason for concern for the warm cover plate. When buying a dimmer switch, notice the packaging will clearly state the wattage rating, e.g. 600 watts. Consequently a dimmer switch with a 600 watt power rating could safely support a 540 watt load.

Dimmer switches are excellent accessories to a dining room, living room, and especially a home theater room. Just make sure you fully understand your lighting application prior to running to a home improvement store to purchase one.


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