Motion sensor installation

A motion sensor turns on the hallway light when you walk in with the shopping, lights up the front door and drive, or tells your smartphone someone is in the flat while you are away. Motion sensor installation depends on what the sensor is for and whether it is wired or wireless.

Types of sensor and how they are fitted

• a sensor in the lighting circuit: fitted in place of a switch or next to the light, with the power off;
• an outdoor light with a built-in sensor: mounted on the wall and connected to the existing cable;
• a battery wireless sensor as part of a smart home or alarm system: mounting, pairing with the hub and a range test.

Where to put the sensor

A sensor reacts to the heat of a moving body, and works best when someone walks across its field of view rather than straight towards it. It should not face a radiator, a sunny window or air from an air conditioner, or it will trigger for no reason. Outdoors, height and angle matter: mounted too low it picks up passing cars and the neighbour’s cat. After fitting, the handyman sets the sensitivity, the on-time and the daylight threshold.

Safety and preparation

Mains-voltage sensors are connected by a handyman qualified for electrical work, always with the circuit switched off. In the job, say where the sensors go, what they are for and which model you have, and for a smart home system give the name of the hub or app.

Common questions