As well as reducing the lighting energy consumption at the site by over 30% and increasing the lighting levels by more than 20%, the Intellect system has also dramatically cut the time taken to reconfigure the lighting when office layouts are changed.

According to Dave Gibson, Building Maintenance Supervisor at Mercedes-Benz (UK) Ltd, the existing light fittings were some 15 years old: "They were equipped with prismatic controllers and didn't comply with the latest health and safety regulations for lighting in areas of high VDT usage," he said, "so initially we looked at refurbishing them to bring them up to standard."

Careful investigation revealed that the old luminaires could not have been made to comply because of the proximity of the lamps to any louvres that were fitted.

"Having realised that a new lighting scheme would be required - and with energy conservation firmly in mind - we then undertook a detailed evaluation of all the sensor-type intelligent lighting systems on the market," continued Gibson.

The result of that process was a decision to have a trial installation of Crompton's Intellect system in the training centre at Milton Keynes. After this proved to be successful, the order was placed for the first phase of lighting the entire building.

"Although other systems could have delivered energy savings, what clinched it for Crompton Lighting was the complete flexibility that Intellect offers because of the luminaires' ability to communicate with one another," said Gibson. "The building is of an open-plan design, and now whenever we change the layout, all we have to do is re-programme the Intellect luminaires; it's a five-minute job to do what would have taken five hours before."

The Intellect programmable luminaires not only incorporate occupancy detection and daylight sensing technology, but can also be programmed to provide light levels anywhere between 3% and 100% of their maximum output, thereby allowing daylight linking and ensuring constant illumination regardless of the age of the tubes. The ability to communicate electronically with each other enables them to be programmed to operate as a group, so that the lighting is balanced, shadow-free and comfortable. All programming is carried out by means of a straightforward hand-held programmer.

Luton-based electrical contractors, B&T Sparks Ltd, have now installed more than 1200 of the luminaires in the main administration block, computer centre and service centre at Mercedes, making this one of the largest Intellect installations in the country. Intellect Moducell luminaires have been used throughout, each fitted with two 55W PL lamps and a Category 2 louvre.

A special master/slave configuration in the dedicated video conferencing suit allows the luminaires to be controlled from a single point with a hand-held dimmer.

The lighting in the staff and visitor washrooms was also upgraded as part of the overall project, using Crompton Solstar and Coolstar downlighters. At least one of the Solstar downlighters is linked into the Intellect communication bus to ensure that there is always some light in the washrooms while there is anyone on that floor of the building. Separate presence detectors switch on the rest of the downlighters as soon as anyone enters the washroom.

In a similar way, presence detectors are used in the huge warehouse area to control the Crompack high-frequency batten luminaires in each aisle.

With regard to overall energy savings, Gibson said: "Although we cannot separate out the lighting from the total metering to determine actual energy savings, we did put an analysis meter on the lighting circuit in a typical office area for a month before and after installing the Intellect system, and this showed a reduction in energy consumption of more than 30%."