How To Install A Dimmer Switch

Do you have a question about dimmers? Dolce Electric Co schedules an in-office electrician Mesa AZ homeowners and businesses can confer with free of charge. You can consult with our local Mesa AZ electricians Monday thur Friday, from 8:00 AM until 5:00 PM. They know our local electrical codes and have the professional experience to answer all your electrical questions and provide you with the expert recommendations you’re looking for. Give them a call today during office hours; they are the electricians Mesa AZ has voted best!

Installing Single Pole Dimmer Switches

A single pole switch is used when your lights are controlled from only one location. Single pole dimmer switch wiring is fairly easy. These have two power carrying wires and one ground. It makes no difference how you connect the power carrying wires (they can be reversed) but be sure to connect the ground properly.

3 Way Wiring

These are use when your lights can be turned on or off from 2 locations. A 3 way switch has three power carrying wires and one ground, it’s important to connect these properly.

With 3 way dimmer switch wiring it’s important to know which wire is the common one. Before you remove your old switch look for the wire terminal labeled common on the back and mark that wire common. Sometimes the common will be identified with a black terminal screw. You will need to know which wire is common so you can reconnect it to the common wire or terminal on your new 3 way dimmer.

The other two power carrying wires, known as travelers, can be black, red or white if plastic sheathed cable has been used. When a white wire is connected to a switch it’s wise to mark it with a wrap of black electrical tape indicating that it is not a neutral wire and that it is a hot wire. These travelers are sometimes identified with a brass colored terminal screw too. It does not matter which traveler wire is connected to the switch’s traveler wires or terminals, they can be flip flopped as long as the common wire is identified and connected to the common on the device.

Ground will be either green or bare and needs to be connected to the grounding wire or terminal on the 3 way dimmer.

Note:
Use only one 3-way dimmer even though the lights can be turned on or off from more than one location. You will be able to adjust your lighting levels from only one location but using more than one dimmer will create problems adjusting light levels. If you want to be able to adjust your lighting levels from multiple locations you will need special electronic dimmers that will need to be installed in all locations controlling those lights.

Now that you know how to wire a dimmer switch make sure your dimmer has a wattage rating capable of safely powering your lights. Add up the wattage of all the lights controlled by the device and make sure that your new dimmer has a wattage rating of at least 20% more than the total lighting wattage being controlled. Most dimmers are 600 watt but 1000 watt and 1500 watt switches are available.

If you would like more information about how to install a dimmer switch or have concerns about overheating, you can consult with our Mesa electricians free of charge. They will answer all of your questions dimmer switch installation and provide you with the information that you are looking for.

More About Dimmer Switches - 6 Important Points

Wiring a dimmer switch to replace a regular switch is fairly simple but there are 6 points you should be aware of:

Never wire a dimmer to a ceiling fan motor or any motor to control the motor speed. These require special speed control switches.
Never connect a regular dimmer to low voltage lighting. A special low voltage dimmer is required for use with low voltage lighting.
Make sure the electrical box is deep enough for a dimmer to be installed in it. Regular switches don’t require much depth but a dimmer is much larger and will require more room. If you need to replace the existing box use a steel box for added heat dissipation as mentioned earlier.
Make sure your home has copper wires and not aluminum. Aluminum wires will be dull grey in color instead of bright orange. It can be hazardous if not connected properly and special connection methods are recommended. See our aluminum wiring repair page for more details.
Be sure to ground the switch. Connect the green or bare wire to the green wire or green screw on the device. If you have a steel box it should also be grounded.
Know what kind of existing switch you have and replace it with the proper device. Single pole switches are replaced with single pole dimmers and 3 way switches should be replaced with one 3 way dimmer and one regular 3 way switch.

Hot Switches And Correcting The Problem

In most cases a warm or hot dimmer switch is not a problem and it’s normal. Dimmers naturally get warm when used but if your device feels unreasonable hot or burning hot it should be checked out by a qualified electrician. There are four reasons why a dimmer switch gets hot and often times a combination of two or more will be contributing factors.

1. Overlamping:

This is the most common cause of a hot dimmer. Each dimmer has a maximum wattage rating that should not be exceeded. The most common size in a residential electrical wiring system is 600 watts but larger 1000 watt dimmers are available too. To check the wattage rating of your dimmer you will need to remove the finish cover plate and find the rating on the front of the device’s mounting bracket.

To determine the wattage being used, add up the wattage of all the light bulbs being controlled by that switch. The closer you get to the maximum recommended wattage the warmer the device will get. If the total light bulb wattage is above the device’s maximum rating you have a case of overlamping. This should be corrected for safety by either upgrading to a larger wattage device or reducing the total light bulb wattage with smaller bulbs, LED bulbs or CFL’s.

2. Removing The Cooling Tabs

Located on both sides of the device are metal cooling tabs that can be removed for fitting the device into the electrical box. When these tabs are removed, the maximum wattage rating of the device has been reduced. Removing the tabs on just one side will reduce the recommended maximum by 100 watts and removing both sides will reduce it by 200 watts. If your switch gets hot and you are not overlamped check to see if these tabs are still present.

Tip:
Plastic electrical boxes offer little heat dissipation where metal electrical boxes deliver much greater heat dissipation. The metal mounting bracket of the dimmer is the main source for heat to escape; it also has those removable metal cooling tabs. The switch’s metal mounting bracket attaches directly to the electrical box, hence when attached to a metal box a greater amount of heat sink transference will occur keeping your switches cooler. When possible, replacing your plastic electrical box with a steel box is another option. A larger or deeper box will provide additional heat reduction too. If you are installing a dimmer switch in a new location and a new electrical box needs to be added, always choose a metal box over a plastic box for heat sink transference. For more expert electrical tips review our web site or contact our Mesa electricians free of charge.

3. More Than One Device In The Same Electrical Box

Having more than one dimmer in the same electrical box can increase the temperature significantly too. Remember, these naturally get warm when used so combining more than one in the same electrical box will increase the generated heat. Also keep in mind that fitting two or more switches in the same box will require the removal of the metal cooling taps on the sides. This, as you know, will reduce the maximum recommended wattage for each switch. If your dimmers are excessively hot, consider lowering the total light bulb wattage being controlled by those devices or upgrading the size of the switches.

Tip:
Just like replacing a plastic electrical box with a metal one will reduce heat, replacing a plastic finish cover with a metal one will also reduce heat. The finish cover attaches to the front of the switch’s mounting bracket which is the primary source of heat dissipation so additional metal equals greater heat transference. A larger size metal finish plate can also be used for increased heat reduction.

Dolce Electric Co schedules an in-office electrician in Mesa AZ that you can consult with free of charge about any electrical question. He has many do it yourself tips that can save you the cost of an electrical service call.

4. The Device Is Failing

A dimmer that is failing will often be making a poor or weak connection inside the device, which can also create additional heat. A small crackling noise can sometimes be heard when a failing switch is energized. Other switches will no longer provide adjustable light levels and only work on or off when they are failing. If you suspect that your switch is failing, now would be a good time to replace it. It won’t fix itself and sooner or later it will fail completely.

As you can see, a warm dimmer is common but an excessively hot one should be corrected. Often times simple adjustment can be made to give you the peace of mind you’re looking for. If you have a concern regarding your switches you can consult with our Electricians in Mesa AZ free of charge Monday thru Friday, during office hours.