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Fluorescent lamps use a ballast which transforms line voltage to a voltage to start up and operate the lamp(s). Newer fluorescent ballasts are usually rated for both 120 volts and 277 volts. Some are rated for only 120 volts, others for only 277 volts (used in commercial environments).
CFLs for the home have a built-
There are four basic types of fluorescent ballasts:
Instant start electronic ballasts use a high starting voltage (about 600 volts) to start very quickly (less than 0.1 seconds). There is no preheating of the electrodes for the highest energy efficiency, but are best suited for a limited amount of switching (10,000 to 15,000 switch cycles before failure). Instant start ballasts are wired in parallel.
Rapid or trigger start electromagnetic ballasts are used in T12 and older T8 fixtures and wired in series.
Rapid start electronic ballasts heat the electrodes while applying the starting voltage (about 500 volts) to start the lamps quickly in about 0.5 to 1.0 seconds. Electrode heating continues while the lamps are on and consume a little more power (about 2 watts per lamp) than instant start ballasts. They can operate 15,000 to 20,000 switch cycles before failure. Rapid start ballasts are wired in series.
Programmed start electronic ballasts start quickly in about 1.0 -
T8 lamps with a newer electronic ballast use about 20 -
T12 fluorescent tubes are not made anymore because of poor energy efficiency. While these lamps are still in stock in some stores, replacing the ballast with a more efficient T8 electronic ballast could be a better choice.
The label on the ballast shows two important labels.
Ballast Wiring Label
Lamp Compatibility Label
LAMP TYPE (4) F32T8
Up to 4 lamps
Fluorescent 32 watts
Compatible Lamp types for this ballast
(4) F32T8 -
(4) F25T8 -
(4) F17T8 -
Light fixtures with ballasts sometimes have labels that show the required type of lamp and ballast ( F32T8).
There are three requirements when matching a ballast to a lamp. In the example above, lamp type F32T8 has the following three requirements:
1. Fluorescent lamp
2. 32 watts
Fluorescent tubes have two common shapes, straight and u-