Around 70 MWS-3DD Direct Dim microwave detection and dimming sensors from CP Electronics are reducing lighting energy costs at the new John Lewis Distribution Centre in Milton Keynes.

Situated mostly in mezzanine areas where occupancy levels vary throughout the day, the ceiling-mounted Direct Dim sensors respond to lack of occupancy by dimming the T5 dimmable fluorescent luminaires installed in these spaces. When someone enters the space the lighting is immediately ramped back up to full output.

Installed by electrical contractor W T Parker, the units were selected for their inherent flexibility and ability to provide a cost-effective solution for the project.

Direct Dim sensors use microwave technology to provide superior multi-presence detection, using DSI or DALI protocols to control the light output of luminaires fitted with dimming ballasts. They can also be used in conjunction with light levels for daylight linking.

The two outputs can operate together or independently, allowing an output to be dimmed whilst the other output is switched. Two switch inputs are also included to allow manual control, for example absence detection on either channel or dimming up/down or override on/off.

As a result of these features John Lewis is able to control its lighting very precisely to meet the needs of each space, and to easily reconfigure the control strategy in response to any future changes in the usage or layout of the space.