What wattage does a 3-way light switch use in a single switch outlet?

Over time, excessive heat could damage the house wiring or the internal components of the dimmer switch. You don't need any special wiring to connect a typical residential dimmer switch. If you have a standard toggle switch in place now that operates the light, a dimmer can replace this switch.

You can even get three way dimmer switches that allow you to operate a light from two different switches. Be aware that dimmer switches can only handle a specific amount of light load. You can typically purchase dimmers that are rated for 600 or up to 1,000 watts of lighting.

Light bulbs are usually clearly marked as to their wattage. Determine the total wattage of the bulbs that are being controlled by any one dimmer. Purchase the correct size dimmer switch to suit your needs.

But keep in mind that the metal heat sink plate on the front of many dimmers can be altered so that you can place multiple dimmer switches next to one another. If you break off the side tabs of the heat sink, as allowed in the instructions, you need to derate the capacity of the dimmer. If you snap off the tabs on both sides of the heat sink a 600 watt dimmer becomes a 400 watt dimmer.

Be prepared for tough decisions when you buy your dimmer switches. There are so many cool ones out there. You can buy one that has all of its controls in the tiny space that is used by a standard on and off toggle switch.

Dimmer switches are made with tiny LED light level indicators, softly glowing night lights, and tap-on and tap-off capabilities. Perhaps my favorite dimmer switch is the one that has a hand held remote control. You sit on a couch or in a chair, point the remote towards the switch and you can dim the lights while still seated.

It is the ultimate couch potato gift! Point of use dimmer switches are also available. You can purchase a dimmer switch for a table lamp.

This device allows you to stop buying three way light bulbs. You can buy a standard higher wattage bulb and use the dimmer to create an infinite amount of different light levels to suit the task. These dimmers are very handy.

While the older light dimmers had a potentiometer (variable resistor- rotating or slide type) as the method of controlling the semiconductors within them, they never were truly a 'rheostat' as you explain. The power to the light was not directly handled by the potentiometer, but by a semiconductor switch called a triac, which had a control signal provided by the potentiometer. A true rheostat to work the common load of 600 watts handled by the standard light dimmer would be about half the size of a toaster (which is a 1200 watt resistance load typically) and generate as much heat...really think that would have worked well in a wall box?

While some newer dimmers have eliminated the potentiometer in favor of touch plates, and the working components are about the same, the efficiency of the semiconductor devices have improved tremendously, and improved efficiency leads to less loss on the switching which results in lower heat dissipation. I hope this helps you for future reference. As a former electrician and now engineer, I am alarmed sometimes at what I read from everyone who is an expert on electricity, and am alarmed at what I see on TV in some of these home improvement shows, etc. EVERYONE is an expert when it comes to electrical work it seems.