How to Replace a Photoelectric Switch

Photoelectric switches, or photo eyes for short, are convenient ways to add outdoor security to your home. These little "eyes" automatically sense when the daylight starts to fade and they automatically turn your exterior lights on. With photoelectric switches installed on your exterior lights, you never have to worry about remembering to turn your lights on. As the sun sets, the photo eye completes the circuit and voila! The lights are on! But if you discover your light is not turning on and you have already replaced the bulb and checked the breaker, then you may have to replace the photoelectric switch. Here is how to do it.

Difficulty: Moderately Easy

Instructions

Things You'll Need:

• New photoelectric switch
• Wire nuts
• Electrical tape
• Wire strippers
• Channel locks
• Voltage tester

1. The first step is to turn the breaker which supplies power to the light OFF. If you are not sure which one it is, then you will have to turn a breaker off and check for power at the light until you find the right one.

2. With the breaker OFF, remove the light fixture's cover from the wall. Double check that the power is off with your voltage tester. You will see the photoelectric switch on the light fixture (it looks like a little round "eye"). On the back side of the photo eye, you will see three wires: a black, a white and a red.

3. Disconnect the three wires one at a time by removing the wire nuts. Now, use the channel locks to loosen the lock-nut holding the photoelectric switch in place. With the lock-nut removed, just slide the photoelectric switch out of the fixture.

4. Next, insert the new photoelectric switch (wires first) through the opening left behind by the old one. Make sure you place the included waterproof ring over the threads of the photo eye to keep rain from getting into the fixture. Use the new lock-nut that came with the new photoelectric switch to secure it to the light fixture.

5. Connect the white wire from the photoelectric switch to both the fixture's white wire and the white neutral wire in the junction box by twisting the copper wires together. Tighten a wire nut over the wires and wrap electrical tape around it.

6. Connect the red wire from the photoelectric switch to the black wire on the fixture. Twist the copper wires together, tighten a wire nut over the wires and wrap with electrical tape.

7. Connect the black wire from the photoelectric switch to the black wire in the junction box. Twist the copper wires together, tighten a wire nut over the wires and wrap with electrical tape.

8. Install the light fixture back onto the wall. Be careful not to nick any wires and make sure no stray wires pop out from behind the fixture.

9. With everything put back into place, flip the breaker back ON. Some photoelectric switches will automatically turn on when power is initially restored. The light should automatically turn off within a few seconds to a few minutes. If the light doesn't automatically turn on when you flip the breaker back on, simply cover the "eye" with a nice layer of electrical tape. Make sure it is completely covered. In a few minutes, the light should turn on. Remove the tape and the light will turn back off.

10. That is all there is to it. Just clean up any debris and you are good to go!

Tips & Warnings

• With your light fixture off the wall, now is a good time to inspect the wires on the fixture and in the junction box to make sure they are still in good shape. If you have to, use the wire strippers to cut off corroded wires and strip off the insulation for a fresh connection.
• Remember, the black wire on the photoelectric switch gets connected to the black wire in the junction box ONLY.
• Remember, the red wire on the photoelectric switch gets connected to the black wire on the light fixture ONLY.

[sigmaknight]

on 8/7/2009 Man! This site was really good. I tried another site and the light never worked.