HPS Lamps
HPS lamps have excellent lumen maintenance, HPS lamps still are generating 90% of initial light output at the midpoint of their life span. Lumen maintenance at the end of life still is excellent at around 80%. ed light output of HID lamps.

Metal Halide Lamps As the graph, the light output of metal halide lamps declines more rapidly than either HPS or mercury vapor lamps. Frequent starting will shorten metal halide lamp life.
Mercury Vapor Lamps Frequent starting or lamp burning position has very little effect on mercury vapor lumen maintenance.

HID Ballast Wiring Diagrams
Ballast Wiring Diagrams for HID ballast kits including Metal Halide and High Pressure Sodium Lighting ballasts. Most magnetic HID ballasts are multi-tap, meaning they can be connected to several different voltages.

Here we display wiring diagrams for metal halide (probe start), metal halide (pulse start) and high pressure sodium HID ballast kits. Most magnetic HID ballasts are multi-tap, meaning they can be connected to several different voltages. Here we display wiring diagrams for metal halide (probe start), metal halide (pulse start) and high pressure sodium HID ballast kits.

HID LAMP LIFE
The rated average life of HID lamps is the life obtained from a large group of test lamps burned under controlled conditions at 10 or more burning hours per start. It is based on the survival of at least 50% of the lamps or groups of lamps and can vary considerably from the average.

Factors affecting HID lamp life include: lamp operating
wattage, lamp operating temperature, ballast characteristics, line voltage and burning hours per start.
Lamp age, or the number of hours a lamp has operated, has very little effect on lamp start ability, although metal halide lamps can require longer starting times as they age.