Finding a Fluorescent Ballast

Did you know some light fixtures have a special device called a ballast?  A ballast provides the voltage needed to start a fluorescent lamp and then continues to regulate its current during operation. Without a ballast, the lamp would quickly be destroyed. Finding the right ballast can be confusing. This is a guide to help you make a choice on the proper ballast for your light fixture.

Factors to Consider

There are a few key specifications to know that will help narrow your ballast search :

1. Lamp Type
2. Number of Lamps
3. Magnetic vs Electronic
4. Starting Method

1. Lamp Type

Knowing the type of fluorescent lamp you have is a great start to your search. Fluorescent lamps are generally divided into compact fluorescent or linear fluorescent (tubes). Lamps will have a part number and specification on them that will help you determine the name (CF for “Compact Fluorescent” or F for “Fluorescent”), shape (T8, T12, etc.), and wattage. For example, an F32T8 is a 32 watt Fluorescent Tubular Lamp.

2. Number of Lamps

Every ballast will tell you how many of a certain type of lamp it can run. Many ballasts can run a number of lamps of a similar type. For example, F32T8 ballasts can generally also run their 2’ and 3’ counterparts. Just knowing the lamp type and how many lamps there are can lead you right to the correct ballast, as many manufacturers make their ballasts in similar sizes and specifications.

3. Magnetic vs. Electronic

Fluorescent ballasts can be either magnetic or electronic. Most newer lights will operate using an electronic ballast, but if you have a lamp fixture that is 10 years old or more, there is a higher likelihood that it operated on a magnetic ballast. You will know that you had a magnetic ballast if you recall your fixture flickering as it turned on, and that they have a hum. They are also known for being very heavy compared to an electronic ballast.

4. Starting Method

There are a few different ways in which a ballast can start a fluorescent tube. The types are Rapid Start, Instant Start, and Programmed Start.

• Rapid start preheats filaments before fulling turning the lamp on, and has a brief delay. These can be found in both magnetic and electronic ballasts, but is more common in magnetic ballasts.
• Instant Start will turn on the moment you flip the switch. They can only be found in electronic ballasts and is the most common form of ballast found.
• Programmed Start are the newest ballasts, a mixture of rapid and instant start designed to mitigate the damaging effects of an instant start ballast while also promoting longer lamp life. They are also only found in electronic form.

Notes

• Some older lamps and ballasts are no longer in production due to the market transition to LED Products. In this case, it is generally easier to replace the entire fixture, or to investigate retrofitting that fixture to an LED one by bypassing the ballast.
  • If you are bent on keeping that lamp in the fixture, try Fulham ballasts! They offer “one-size-fits-all” ballast solutions that are useful for very specific lamps that use very specific ballasts. They offer a guide for finding the right ballast for your lamp, and even provide wiring diagrams for how to install that lamp! You can find their wiring diagrams here.
• While most manufacturers design their ballasts with a similar footprint, there is still a chance that the ballast you are getting does not have the exact same dimensions of your old one. It is important to make sure before you purchase that you will have the space for your new ballast, and that you are comfortable making new mounting holes for installation.
• The same way that manufacturers account for uniform dimensions, they also tend to have the same wiring as other ballasts that operate the same lamp and number of lamps. Pay attention to the wiring on your current ballast and look for it on the one you are using as a replacement.