4' T8 Fluorescent Instant Start Ballasts - Choose Ballast Factor

Every fluorescent instant start ballast has either a low, normal, or high ballast factor. Low ballast factor uses .77 of the lamp's rated watts, normal ballast factor uses .88 of the lamp's rated watts, while high ballast factor uses 1.15 of the lamp's rated watts.

1-lamp Instant Start T8 Ballasts Low Ballast FactorInstant Start Normal Ballast FactorInstant Start High Ballast Factor