Electrical and illumination characteristics of energy-saving fluorescent lighting as a function of potential

Various combinations of F40-T12, F96-T12 and compact energy-savings fluorescent lamps with core-coil and solid-state ballasts were tested at laboratory facilities. The illumination (footcandles), the active (watts) and reactive power consumption, as well as the harmonic content (percentage of the fundamental 60 Hz frequency) of the load current, were measured as a function of varying voltage levels. The electrical parameters showed markedly different characteristics when functionally related to voltage, in comparison to results obtained in 1976 under the same testing conditions. Fluorescent lighting incorporating solid-state ballasts revealed a harmonic content in the measured current larger at most odd multiples of the fundamental frequency than that obtained for lighting systems equipped with core-coil ballasts. Some compact energy-efficient fluorescent lamps with core-coil ballasts exhibited power factor readings as low as 0.50 at the voltage of 120 V. In most cases, strong correlation between illumination and varying voltage levels was not obtained over the range of voltages applied. A trend towards improved lighting efficiency occurred as potential was decreased from the nominal base of 120 V, i.e fc/W increased. >