From Issue #4

Add a motion-sensitive light switch

11/04 — Somewhere in your house, you may have a hallway, pantry, or other room with two primary entrances. It also probably has two three-way light switches. People flip one switch on their way in and the other on their way out. Boring!

If the doorways face each other, a more convenient and energy-efficient solution is to install a motion-sensing light switch next to one doorway. For me, it was a storage room between my house and garage. Rather than fiddling with switches, people coming from the house now trigger the light as they enter the room. From the garage side, merely opening the door turns on the light. Since my wife and I often carry packages through this room, this new gadget was welcomed gratefully.

Installing an automatic switch requires only a screwdriver and voltmeter. However, if you’re not comfortable working with electrical house wiring, you should not attempt this project yourself.

Step 1: Buy the Switch Automatic light switches can be purchased from home automation catalogs, home improvement stores or electrical supply houses. Choose one with a sufficient selection of on-intervals, a 180-degree sensing range, and an override switch to force it on or off. Although some less expensive models are limited to use only with incandescent lights, most models have a full relay, and work with any type of lighting. Select a unit that doesn’t require a “neutral” connection, as this can complicate installation. Decide if you need a built-in photosensor. In a well-windowed hallway you may want the lights to come on only if it’s sufficiently dark outside. You also need a faceplate in the color that best matches your room, a blank faceplate to replace the second switch, and some wire nuts.

Step 2: Turn Off the Power You need to safely cut the power to the light switch you are replacing. This is most easily done by turning on the light, going to your breaker box, and turning off individual breakers until the light goes off. (A friend with a loud voice may be helpful here.)

Step 3: Remove the Old Light Switches Using a screwdriver, remove the faceplate and light switch from each box. Each light switch should have four wires attached to it. One wire will be attached to a green screw and may be un-insulated, and another wire will be red. Remove all the wires from both switches. They will either be attached to screws or pushed into holes in the switch. If the wires are pushed into holes, there are release tabs in smaller holes next to the wires. Push a small screwdriver onto the release tab and the wire should come free. In one box, connect the two remaining wires together with a wire nut, put another wire nut tightly over the red wire, fold the wires back into the box, and screw on the blank faceplate. In the other box, put a wire nut tightly over the red wire and fold it back into the box.

Step 4: Identify Your Wiring In the uncovered box, you need to identify the two remaining non-ground wires, which were attached to the switch. One provides power while the other goes to the light (or “load”). Carefully pull out the wires you want to examine, and the ground wire, and position them where they cannot touch anything. Then turn the breaker back on. Using a voltmeter, carefully touch one probe to the ground wire, and touch the other to each of the two wires that were attached to the switch. The wire that shows 120 volts is the “hot” wire. Now turn the breaker off again.

Step 5: Install & Set Up the Switch Using wire nuts, connect the new switch as shown in its enclosed instructions. Position the switch properly in the box, and screw it into the box. Then follow the instructions to adjust it for proper operation and on-interval. Finally, install the faceplace. You’ve completed the project!

Sometimes, it’s the little things in life that make all the difference. Next time you approach your sensor-equipped room or hallway, feel free to smile a little about the light switch you didn’t have to reach for.

Project Snapshot

Estimated Time to Complete: 1 hour

Difficulty Rating: 1 [1=Child’s Play, 2=Use Both Hands, 3=Call for Backup!, 4=Obi-Wan Worthy]

Estimated Cost: $63

The Problem You have a room or hallway with two entrances and a whole lot of through traffic. People are tired of flipping the light on as they enter and off as they leave, and you’re tired of turning off the lights in a space that is often empty.

Parts Needed • Hubbell WSS1200 H-Moss Motion Switching System ($59.95) • A Decora-style faceplate ($1.99) • A blank faceplate ($0.39) • 6 wire nuts ($0.49)

Project Steps 1. Buy the switch. 2. Turn off the power. 3. Remove the old switches. 4. Identify your wiring. 5. Install and set up the switch.

Switch Tip

Make sure the range of the light’s automatic switch exceeds the distance between your two doorways.

About the Writer

Name: Jeff Winston Age: Over 30 City/State: Eastern Massachusetts Occupation: Engineer One thing people would be surprised to know about me: I recently converted my house to energy-efficient lighting.