The National Electrical Manufacturers Association (NEMA) has published LSD 14 Guidelines on the Application of Dimming to High-Intensity Discharge Lamps. This white paper, last published in 2002, was produced by NEMA’s Lamp Section and is available for free download.
LSD 14 provides guidance on the application, combination, and practice of dimming of high-intensity discharge (HID) lighting systems. The three technologies discussed are high-pressure sodium, metal halide, and mercury vapor, each of which responds differently to manipulation.
This revision incorporates additional systems and updates the recommendations for dimming in terms of output and the systems employed.
Ideal applications for energy-saving HID dimming systems include parking garages, warehouses, shipping docks, streetlights, supermarkets, ball fields, factories, and security lighting. They are often used in conjunction with daylight lighting systems.