What are the power requirements for T8 fluorescent lamps?
It may be expected that the electric power needed to operate a 32-watt T8 fluorescent lamp will be 32 watts; however, this designation is simply the nominal power of the lamp. The relevant American National Standards Institute (ANSI) document states that the rated lamp power is 32.5 watts under standard test conditions (ANSI C78.81-2005). ANSI further indicates that average lamp power shall not exceed 34.6 watts, which is 6.5% above the rated value. Since this upper limit applies to the average value of the power needed to operate 32-watt lamps, it is possible for individual lamps to exceed 34.6 watts. Since specifiers may select lamps based on efficacy, the variation in lamp power could make calculations of lamp efficacy more difficult without knowledge of the actual power and the associated uncertainty for a specific lamp model. ANSI considers the 4-foot, 32-watt T8 lamp to be a rapid-start lamp, but it is commonly operated using an instant-start circuit in which the two pins on each
