Effects of dimming 150W ceramicmetal

Dimming high-intensity discharge (HID) lamps is often proposed as part of energy management schemes for lighting installations. However, the impacts of dimming on HID lamp performance are not well characterised. The impacts of operating 150W ceramic metal halide discharge (CMH) lamps for prolonged periods (up to 11 000h) at reduced powers have been quantified. CMH lamps of 150W operated at 100W and 76W showed no significant differences in lumen maintenance, survival and colour rendering index compared to similar lamps operated at the rated power for the same time. The experiments confirm that the concept of dimming CMH lamps can be employed in roadlighting schemes, such as NumeLiTe, without detrimental consequences on lamp performance. 1