The track head moves along the track and may be integrated into the track or suspended in a pendant mount. Some individual track lights can also be connected directly to a junction box. Ballasts are typically housed in the track head, although ballasts may also be recessed into the ceiling plenum. Track lights also offer options for switching individual lamps or groups of lamps. Accessories available for track lights include lenses that alter the beam shape, louvers and tubular shields that cut down on glare, and filters that change the color of the light.
Some products also offer a ballast fuse that prevents damage from voltage surges.
The metal halide track lights pay for themselves in just over five years, under the assumptions shown, whereas the HPS lights take more than seven years to pay off. The cost-effectiveness of HID track lights depends on the intensity of their use and on local electricity costs. Table 2 presents a sample calculation. Energy efficiency and long life of HID lamps make up for higher first costs most quickly in areas where electricity costs are highest, and in applications where maintenance costs are high and usage is most intense. Try before you buy.