The requirements in this standard cover indoor and outdoor ballasts, including starting circuits for the operation of high-intensity-discharge lamps, and associated equipment, in accordance with the National Electrical Code, from an alternating-current power supply with nominal ratings of 600 V rms or less. High-intensity-discharge lamps include mercury, metal halide, high-pressure sodium, and similar types. For convenience, although technically not HID lamps, low-pressure sodium lamps are included with the group. The requirements for ballasts consisting of resistance only are excluded from this standard.