Performance of electronic ballast and controls with 34 and 40 Watt F40 fluorescent lamps

The electric and photometric characteristics of 40-W, cool white (CW) and 34 W, so-called lite white (LW) F40 T-12 fluorescent lamps were compared by operating them with electronic ballasts, static controls, and dynamic controls of different designs. The energy-saving krypton-filled 34 W lamp-ballast system is, at best, slightly more efficacious than the standard 40 W argon-filled lamp-ballast system by virtue of the use of lite white phosphor. The 34 W system is shown to have limitations that include higher starting voltages, reduced temperature range of operation, smaller dimming range, and poorer color rendering than the standard cool white 40 W lamp system