How to Wire a Motion Detector to an Exhaust Fan Circuit

Motion detectors aren't just for outdoor lights.

Motion detector circuits have been used in security and security lighting for many years. Today, as the world begins to work on conserving energy, motion detectors are being used more often in homes and businesses. Using motion detectors to control lighting in businesses can lead to cost savings in electricity. The same can be said for homes. Motion detectors can also be used to control bathroom exhaust fans and garage exhaust fans.

Things You'll Need

• Screws
• Screwdriver
• Drywall saw
• Electrical box
• Plastic twist caps
• Wire strippers
• Wire cutters
• 12-2 Romex wire

Instructions

1. Shut off power to the exhaust fan at the main breaker.

2. Cut a hole in between the joists to mount the sensor electrical box, using a drywall saw. Secure the electrical box to the existing joists, using the screws and a screwdriver.

3. Run a section of Romex cable from the sensor electrical box to the exhaust fan. Strip 1/2 inch of insulation from the black and white wires at each end of the new Romex cable, using wire strippers. Move to the exhaust fan.

4. Remove the plastic twist cap and unsplice the hot wire from the exhaust fan, using wire cutters. Connect the hot wire to the black wire of the new Romex cable and add a new plastic twist cap.

5. Connect the black wire of the exhaust fan to the white wire of the new Romex cable and add a new plastic splice cap. Move to the motion sensor.

6. Connect the black wire of the new Romex cable to the black wire of the motion sensor. Connect the white wire of the new Romex cable to the white wire of the motion sensor. Place plastic twist caps on both splices. Connect all ground wires at both the motion sensor and the exhaust fan.

7. Secure the motion sensor to the sensor electrical box and turn the power back on. Test the circuit.

References

• Reader's Digest: Installing a Remote Motion Detector for Lighting