What Turns You On? A Guide To Fluorescent Ballasts

Fluorescent Ballast
Replacing old fluorescent ballasts? Adding new ones? The array of fluorescent ballasts is more diverse than ever before, so you’ve got to know exactly what you’re looking for. Whether you want to reduce the noise and flickering of your lights, prolong their rated lives, or save as much energy as you can, there’s a ballast out there for you.

But first, some fundamentals:

What is a fluorescent ballast?

It’s an electrical device used to power many kinds of fluorescent lights. The ballast supplies the right voltage to start and run the lights, and controls the current during operation. The right ballast should allow your lights to turn on quickly, and prevent annoying flickering or humming.

Which is the right ballast? (Magnetic vs. Electronic)

There’s an easy answer to this one. The U.S. Department of Energy phased out most magnetic fluorescent ballasts back in 2010. Electronic ballasts are more efficient and function in a more reliable way.

Let’s compare:

Magnetic ballasts: These use a core made of laminated steel plates, wrapped in a copper coil to regulate the lamp’s voltage by magnetic inductance. While magnetic ballasts are less expensive, they’re also less efficient, noisier, and heavier than electronic ballasts. Magnetic ballasts also don’t alter the frequency of electricity supplied to the lamps, so you can expect the lights they control to flicker.

Electronic ballasts: To function, these replace the older magnetic core with electronic components that increase the standard operating frequency of electricity from 60 cycles per second to about 20,000, or 20+ kHz. This reduces that pesky flickering that causes headaches and eyestrain. Compared to magnetic ballasts, electronic ones are lighter, quieter, more efficient, and they produce less heat.

Any expert will tell you to use an electronic ballast to power your fluorescent lights. However, modern ballast technology provides 3 popular varieties of electronic ballasts. You should pick one based on how you use your lights.

The 3 Electronic Ballasts:

1. Instant Start Ballast

These ballasts will make sure your lights turn on the moment you flip the switch, without delay or flashing. They supply a high initial voltage to turn on the lamp, starting the discharge between the lamp’s unheated electrodes. Instant start ballasts don’t provide any extra heating voltage to the electrodes before or during operation, so they use less power than other electronic ballasts. These ballasts are best suited to applications where the lights are left on for extended periods of time, because their method of starting the lamp with unheated electrodes is much more damaging. The more your turn the lights on and off, the more you reduce their lives. See them here.

2. Rapid Start Ballasts

Rapid start ballasts preheat the fluorescent lamp’s electrodes in an attempt to extend the lamp life. They have separate sets of windings that provide a low voltage to the electrodes, heating them to about 1,470 degrees Fahrenheit in 1-2 seconds. This diminishes the power surge needed to start the lamp, which is what degrades the electrodes. These ballasts also supply extra electrode heating voltage after the lamp starts, using slightly more electricity than instant start ballasts. You should expect these ballasts to start only after a brief delay, in order to heat up properly. See them here.

3. Programmed Start Ballasts

This is the newest kind of ballast, designed to reduce the amount of energy used by rapid start technology and the damaging effects of instant start technology. They operate in a more structured series of steps. First, they preheat the electrodes, just like the rapid start systems. While this goes on, the ballast reduces glow current, which is what causes blackening and lamp degradation. When the electrodes reach the perfect temperature, the ballast applies voltage to strike an arc, lighting the lamp. See them here.

For more information about fluorescent ballasts, check out this paper from the National Lighting Product Information Program.

Annie Josey

Annie was the E-Commerce Marketing Specialist at Pegasus Lighting from June 2012 to October 2013. She has a background in English literature, and loves using language to help illuminate the world. So covering lighting news and tips naturally fit her interests. In her personal time she enjoys painting, biking, and reading.