How do I install a motion sensor light switch?

Installing a motion sensor light switch requires turning off power at the breaker and working with live wires - while homeowners can legally replace switches in Ontario, this work carries electrocution risk and should be done carefully or left to a licensed electrician.

Motion sensor switches are excellent for energy savings and convenience, automatically turning lights on when you enter a room and off when you leave. The installation process involves removing your existing switch and connecting the motion sensor's wires to your home's electrical system.

Before starting any electrical work, shut off power to the circuit at your electrical panel and verify it's off using a non-contact voltage tester. Remove the existing switch by unscrewing it from the wall box and carefully pulling it out. You'll typically find three wires: a hot (black) wire bringing power in, a switched hot (black or red) wire going to the light fixture, and a neutral (white) wire. Some older homes may not have a neutral wire in the switch box, which is required for most motion sensor switches.

Motion sensor switch installation involves connecting the sensor's black wire to the incoming hot wire, the red or blue wire to the switched hot going to the lights, the white wire to the neutral bundle, and the green or bare wire to the ground. The sensor unit is typically larger than a standard switch, so ensure your wall box has adequate space. Most motion sensors have adjustment dials for sensitivity and timer duration that you'll set after installation.

ESA requirements in Ontario don't require permits for replacing switches like-for-like, but the work must be done safely. If you're adding new circuits or installing switches in new locations, ESA permits are required. Motion sensors work best in rooms with clear sightlines and should be positioned to avoid false triggers from heating vents or moving curtains.

Safety considerations are critical - electrical work can cause fires or electrocution if done incorrectly. If you're uncomfortable working with electrical connections, encounter unexpected wiring configurations, or don't have a neutral wire in your switch box, contact a licensed electrician. Many motion sensor installations in Ottawa cost $150-$250 including the switch when done professionally.

For complex installations or if you're unsure about your home's wiring, Electrical Ottawa's licensed electricians can ensure safe, code-compliant installation of motion sensor switches throughout your home.

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