100 Watt M90 120/277 Volt F-Can Metal Halide BallastMetal Halide Ballast Cross Reference: Advance Ballast 72C5381NP Sylvania Ballast M100 120 277 F CAN Universal 11210239CTC Sola E MZAFTJ100F Grainger 3V564 High Intensity Discharge (HID) lamps require a ballast to apply starting voltage to the lamp and establish current flow an arc between the lamp electrodes. Without a ballast, the arc will extinguish or draw increasing current until some circuit element burns up. Ballasts provide system stability by