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 limiting the current that can be drawn.

Core and Coil metal halide HID ballasts are used in over 90% of all HID lighting. Replacement ballast kits contain the appropriate core and coil, a properly rated capacitor and all components required for ballast replacement. The James Lighting, core and coil, HID ballast kit is ideal for a wide variety of lighting applications, including factories, warehouses, gymnasiums and retail stores.