Choosing the Right Fluorescent Ballast
Unless you're an electrician, it’s probably news to you that many fluorescent lights, such as those used in your kitchen or garage, require electrical devices called ballasts to operate. Ballasts supply the proper voltage to start and run the majority of fluorescent lights. Although typically connected by wires in-between the power source and the bulb, ballasts are sometimes included within the bulbs. This is often the case with compact fluorescents, but this rarely happens with fluorescent tubes.
If your fluorescent bulb doesn’t specify that it has a built-in ballast, chances are, you’ll need to purchase one separately. But with the wide array of options on the market, we understand how finding the right ballast can be a little confusing. That’s why we’ve updated our previous article on choosing fluorescent ballasts: to make this process even easier. The comprehensive information below will help you select the fluorescent ballast you need.
Five Factors to Consider
Knowing the type of fluorescent light you will use with your ballast is a good start to your search. They can be generally divided as compact fluorescents or fluorescent tubes. When researching your fluorescent bulbs, pay attention to attributes that will help you narrow your options down. Bulb name (such as 2-pin, 4-pin, T8, T12, etc.), base type, and wattage are usually the most helpful information.
When considering a ballast for your lamp, make sure they have corresponding ANSI (American National Standards Institute) codes. Matching ANSI codes guarantees that the ballast you chose can be used with your lamp. However, ballasts are often compatible with more than one lamp, and vice versa. Based on design and start method, certain ballast options may be preferable to others because they can help your lights operate more efficiently, have longer life spans, or use less energy.
Magnetic vs. Electronic Ballasts
Fluorescent ballasts can be either magnetic or electronic in design. Unless you are simply wanting to replace an older magnetic ballast, try to purchase lights that use a newer electronic ballast instead. Although simpler and cheaper, magnetic ballasts tend to flicker and hum, and they consume excessive amounts of energy to operate. On the other hand, electronic ballasts don’t flicker or hum, and they use modern, more energy efficient technology.
Because an initial current can be quite high, fluorescent ballasts are needed to safely start fluorescent tubes. Fluorescent ballasts have four main types of starting methods: Preheat Start, Rapid Start, Instant Start, and Programmed Start. The latter two (with the most current technology) are the most popular. Each start method has its advantages and drawbacks, as detailed in the following chart.
Preheat Start (Magnetic Design Only)
Preheat Start ballasts require a starter (usually built-in) to establish the circuit through the ballast and pre-heat the lamp filaments. When the filaments have heated up, the ballast then provides a suitable voltage to the lamp. Several seconds may be required to complete the starting operation.
Rapid Start (Magnetic or Electronic Design)
Rapid Start ballasts preheat filaments to the proper temperature before fully turning on the lamp. Usually, this is only a brief delay. This method diminishes the stress on the filaments from a strong, initial power surge, thereby extending lamp life.
Instant Start (Electronic Only)
Instant Start ballasts turn lights on the moment you flip the switch. They provide the quickest, most energy-efficient lighting and are intended for areas with infrequent switching and “on” cycles of several hours, as the initial surge from turning on the lamps can damage them in the long run. These ballasts are ideal for offices, warehouses, and retail spaces.
Programmed Start Same as Programmed Rapid Start (Electronic only)
Programmed Start ballasts are the newest ballasts on the market, designed to reduce the energy used by rapid start ballasts as well as the damaging effects of instant start ballasts. These ballasts provide slower-starting, energy-efficient lighting that prolongs lamp life and performs well in frequently switched applications. These ballasts are ideal for hallways, stairwells, and bathrooms.
Ballast Factor and Light Output
Lastly, ballast factor is a measure of the total lumen output for a combined lamp-ballast system. By selecting a ballast with an ideal ballast factor, you can optimize the light output of your fluorescent lighting system and maximize your energy savings. To estimate your total system lumens, multiply the rated lumens of your lamp by the ballast factor. For example, 3200 lumens x 0.77 BF = 2464 total system lumens.
- Low Ballast Factor (below 0.77) Lower energy usage and reduced light output. Ideal for hallways and bathrooms.
- Normal Ballast Factor (0.77 to 1.1) Near rated energy usage and light output. Ideal for most applications, including offices and retail stores.
- High Ballast Factor (above 1.1) Higher energy usage and up to 10% more light output. Ideal for warehouses and areas with high ceilings.