Compact fluorescent lamps (CFLs) for the home have a built-in ballast at the base. In commercial buildings CFLs are commonly used in recessed lighting and use a separate ballast to power the lamps (bulbs). Commercial line voltage mostly uses 277 volts to power the lighting circuits. Most newer CFL ballasts operate on 120 V to 277 V. The 26 watt ballast shown below can be used for 1 or 2 lamps.
CFL ballasts and sockets have push-in wire connectors. The push-in connectors on ballasts have a button or slot to release each wire. A replacement ballast with a release slot will contain a tool to insert into the slot to release the wires.
CFL ballast rear view
Slots for wire release
CFL ballast side view
CFL ballast front view
CFL Ballast with 1 Lamp Wiring Diagram
CFL Ballast with 2 Lamp Wiring Diagram
Red wires connect to one side of the lamp, blue wires connect to the other. Yellow terminals are not used.
Red wires connect to one side of one lamp, blue wires connect to one side of the other. Yellow terminals wires connect to the remaining pins.