Probe-start and pulse-start metal halide ballasts are not interchangeable, and a ballast designed for one lamp family will either fail to strike or shorten lamp life when used with another. Magnetic and electronic versions differ in warm-up behaviour, lamp-flicker tolerance and dimming support. Input voltage taps — 120, 208, 240, 277, 480 — must be set for the actual supply, not the nameplate default.
This group covers metal halide and high-pressure sodium ballasts, in the common wattages and voltage taps, with ANSI codes listed.
