Occupancy sensors and vacancy sensors enable lights to be automatically turned on or off when presence is detected within the sensor's range. Motion sensors are largely used in commercial spaces and offices, warehouses, bathrooms and residential homes. These motion sensor light switches use different sensing technologies to trigger the light on/off. Using occupancy/vacancy sensors results in a more energy efficient and smart lighting control system. Motion sensors can be mounted a variety of ways: ceiling mount, wall mount, high bay mount and in-wall.
Motion Sensor Switches
In-wall motion sensors are installed close to doors and entrances and detect motion when the door is opened or when someone passes by. They can also be installed in the middle of long hallways and corridors to keep the lights on while someone is walking. These occupancy sensors normally have a button for manual on/off operation and a sensor window for automatic operation. In-wall motion light switches are most often used in offices, bathrooms, locker and shower rooms, laundry rooms and warehouses. Vacancy sensors come in different colors like black, brown, almond, white, ivory and light almond.
Motion sensor switches use varying degrees of technology to activate the sensors, including passive infrared (PIR) and ultrasonic technologies as the most common types. Passive infrared occupancy sensors use infrared heat to activate. When it detects heat within its line of sight, like if someone passes by, the sensor turns the light on automatically. PIR sensors are used in restrooms, small offices, conference rooms and bedrooms. On the other hand, ultrasonic motion sensors use sound waves as a trigger to activate. Ultrasonic sensors are active sensors that send out sound waves throughout the room and measure the time it takes for them to bounce back. Other sensor technologies are also available like dual technology sensors, microphonics and light sensitivity.
Occupancy Sensors and Vacancy Sensors
Occupancy and vacancy sensors are ideal for energy efficient lighting by making sure lights are on only when the room is occupied and off when unoccupied. Sensor switches fall under two categories: occupancy sensors and vacancy sensors. Occupancy motion sensors automatically turn the lights on and off. When motion is detected, the light will turn on, and then will turn off after a set period of time. Vacancy sensors automatically turn the light off, but need to be manually turned on.
Ceiling Mount Motion Sensors
Ceiling mount motion light switches are ideal for larger rooms that require sensors having a bigger coverage. Having motion sensors mounted on the ceiling overcomes the problem of having large objects obstructing the sensor's field of view, therefore not being able to detect the presence of someone. Ceiling occupancy sensors have a circular detection range from the ceiling going down so it can work over obstructions. These motion sensor switches also use PIR, ultrasonic and other technologies to detect activity. Ceiling mount sensors are installed in offices with cubicles, partitioned bathrooms, shower rooms, storage rooms and stairwells.
Wall Mount Motion Sensors
Hallway motion sensors have an elongated sensor range designed for long hallways, corridors and stairs. Wall mount sensors, like most occupancy sensors, can control multiple lights using 120-277V or 24V low voltage. These motion sensors are mounted on walls near entrances to conference rooms, open offices, lunch rooms and stairwells. Use occupancy wall sensors for automatic on/off operation, or vacancy sensors for manual on and auto off. Passive infrared wall sensors are the most common for a variety of applications, and ultrasonic and dual technology sensors are also available for more accurate sensing.
Fixture Mount Motion Sensors
Fixture mount motion sensors are mounted onto high bays, linear strip lights, vapor tight fixtures and wraparounds for commercial and industrial applications. High bay sensors are used for warehouses, storage areas, gymnasiums and garages. When mounted on fixtures, these sensors detect activity from high above the ceiling, similar to how ceiling mount sensors work. The lights activate when someone walks in proximity of the sensor and stays on until a set period of time. Fixture mount sensors have different degrees of coverage including 360° and aisleway sensors. There are wet location sensors applicable for outdoor fixtures as well.