Legrand’s lighting and motion management systems, which are designed to make industrial, commercial and domestic buildings more energy efficient, encompass switch sensors that reduce the amount of time lighting is left on unnecessarily.
“Lighting, together with heating and air-conditioning, accounts for the greatest energy consumption and electricity costs of a building,” states Luk Ivens, general manager, Legrand Southern Africa. “With the installation of an automatic lighting and motion management system, which ensures there is exactly the right amount of light when and where it is needed, energy savings of up to 60% can be achieved.
Legrand’s lighting management sensors are used to monitor the detection area for occupancy and to control lighting and HVAC circuits. Lighting is automatically switched on when a person is sensed. Where sensors are equipped with a built-in light level sensor, the lighting will be kept off when sufficient natural light is available. When the area is vacated, the lighting automatically switches off after a pre-set time delay.
Motion sensors, with an automatic switch on/off facility, are recommended for areas with little or no natural light, for example in passageways, bathrooms and equipment rooms.
Passive infrared (PIR) technology of motion sensors detects occupancy up to 8m, by identifying the difference between heat emitted from the human body in motion and the background space.
Lighting management sensors – designed for shops, offices, healthcare buildings and warehouses – have a manual or automatic switch on/off, according to whether there is anyone present and the natural light level. These sensors have built-in adjustable lux sensors that keep the lighting switched off if there sufficient natural light.
Detection of lighting management sensors is based on PIR technology and dual technology (DT) which ensures maximum sensitivity and coverage in applications for optimum reliability and energy saving.
Legrand sensors work in occupancy mode, where are lights are automatically switched on or off according to occupancy, or in vacancy mode for additional energy saving, where lights are manually switched on and automatically switched off when the person leaves the area.
For enhanced flexibility, switch sensors can be combined with room controllers to manage a number of lighting and ventilation circuits. For example, in areas where daylight is unevenly distributed, a sensor can be combined with a row of luminaires to measure motion and light levels. The dimming controller regulates each row of luminaires and supplements the external light to obtain the required pre-set light level.
