Ballast Factor (BF):- Is the ratio of light output from a lamp operated on commercial ballast to the light output of that same lamp operated on "reference ballast" as specified by ANSI standards.
Warm Start/ Preheat:- The ballast heats the lamp electrodes and lamp is strated with fixed ignition voltage. This reduces the stress on the lamp filament hence it increases the life of the lamp.
Instant Start / Non Preheat:- The lamp is put on without preheating of the filament. This leads to stress on the lamp filament therefore it affects the life of the lapm. These ballasts to be used where switching is not frequent.
Parallel Circuit:- Ballast circuit in which the lamps connected to one ballast will operate independently of one another, if one lamp fails, the rest will stay on.
