Save Money and Help the Planet By Installing an Automatic Light Switch

by Home DepotOctober 31, 2012

Being wasteful can cost us both in our wallet and in our environmental footprint, especially when it comes to unnecessary electricity use. Have you ever opened the door to an infrequently used closet or bathroom, only to discover that the light was left on hours, days, or even weeks before?

Similarly, even the most conscientious monitor can grow frustrated when housemates, spouses, or children forget to turn the light off when they leave a room.

Thankfully, technology provides an answer in the form of automatic light switches. The price point is now low enough to make installing them a worthwhile, money-saving home project that requires little-to-no electrical knowledge.

Ranging from about $20 up to elaborate $50 models with highly programmable settings, automatic light switches can quickly pay for themselves, depending on the room and the amount of wasted electricity being burned prior to their installation.

Although useful in any room, motion-sensing switches are best utilized in bathrooms, closets, and guest rooms, where lights are most likely to be left on and forgotten about. Their no touch, instant on feature is also something you will appreciate.

After picking out your new switches, you will want to gather a few tools. For this project, you’ll need:

  • Voltage tester
  • Phillips head screwdriver
  • Flat head screwdriver
  • Wire stripper
  • Pliers
  • Electrical tape
  • Wire nuts, (often supplied with the switch)

To get started, begin by turning off the power at the circuit breaker. This is the most important step — if you fail to cut the power to the switch, you risk being electrocuted. If your home has fuses, remove the fuse from the fuse box. Finally, leave a note on the circuit breaker to let anyone else in your house know not to turn the circuit back on.

  1. Once you’ve assured that the power is off, remove the wall plate around your existing switch with your screwdriver. Use the voltage tester to verify that the power is indeed off at this location.
  2. Remove the mounting screws holding the switch to the wall.
  3. Take a photograph of the current wire configuration on the back of the switch, in case you need to refer to it later.
  4. Remove the wires from the back of the switch.
  5. On the remaining wire, use the wire strippers to insure that about ¾ inch of the wire protrudes from the insulation.
  6. Unlike conventional switches, automatic sensor switches (and dimmer switches), typically have wire splice connections rather than screw terminals. Start with the green/bare ground wire, twisting the ends together with pliers. Once firmly connected, screw on a wire nut (pictured – the little yellow caps) to secure the contact and insulate the wire ends. Repeat this process with the two house power wires (which are both usually black, though other colors are possible).It’s worth noting that in some cases, white wire is used as a power lead and is marked as black with electrical tape. You may also notice that an additional wire is present – this is for a 3-way switch installation, where multiple switches can control one light fixture. A single pole switch will not have this extra wire. The diagram below shows a typical schematic of how to wire your new switch. Please go by the instructions supplied with your switch, as wire colors do vary among different brands. The pictures you took in step 3 may really come in handy now.
  7. Wrap the wire nuts with electrical tape to help hold the nuts in place and minimize the chance of short circuits.
  8. Replace the switch in the wall and screw the mounting brackets and wall plate back into place.
  9. Turn the power back on and test your new switch!

Whether you choose a programmable switch or a simple motion-detecting on/off switch, eliminating the unnecessary lighting of unoccupied rooms can take a healthy dent out of your power bill. When it comes to energy efficiency, conservation is the easiest and best solution!

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