Wondering which ballast to choose? Is it a standard fluorescent ballast you need or are you looking for something more specialized like a sign ballast, dimming ballast, or circline ballast? Look for three key specs to help with your decision: Lamp type, start method, and ballast factor.
What type of lamp are you using? Because they go with the most common fluorescent lamp types, chances are you will need an F32T8 ballast, F40T12 ballast, or F54T5 ballast, but your lamp may be different and require a different ballast. Determine what that lamp type is before you go any further.
Once you have determined your fluorescent lamp type, don't ruin your investment by burning your bulbs out prematurely. Consider where your fixture is installed. Offices, boardrooms, and retail spaces tend to stay lit for long periods, so use an instant start ballast, which is the least expensive and most common option. Hallways, stairwells, and bathrooms are switched more frequently, so use a programmed start ballast that will heat the lamp cathodes more slowly and prolong the lamps' life.
Next, you will need to consider light output. Unlike other light bulbs, fluorescent tubes will not necessarily be the exact brightness noted on the label. That number you see, expressed in lumens, is figured using a normal light output ballast with a ballast factor between 0.77 and 1.1. If you don't need your room quite as bright, use a low output ballast with a ballast factor below 0.77. If you are lighting a warehouse or manufacturing facility where brightness is important, you will need a high output ballast with a ballast factor above 1.1.