The ballast is a critical component of most fluorescent light fixtures. Not only does it play a role in optimizing the light’s energy efficiency, but it also helps extend the fluorescent light’s overall lifespan.

Sometimes referred to as a fluorescent light fixture’s “Control Gear” a ballast is essentially a small, rectangular device that transfers the correct amount of voltage that the lamp needs to both start as well as regulate the flow of electrical current necessary for safe operation. If a fluorescent light fixture didn’t have a ballast, the lamp itself would draw too much power. In time, it would overheat, burn out, and potentially even catch fire.

For as simple as it may look at first glance, there are actually a lot of potential ballast options that might be used in a variety of fluorescent light fixtures. Some are better suited for individual residential lights, while others are better suited to commercial building fluorescent lighting systems.

To understand the type of ballast that is right for your home or business, we’ll need to take a closer look at some important details. We can then filter down to find the best ballast for your preferred fluorescent light fixtures.

The Type of Fluorescent Light

The type of fluorescent light fixture you prefer will influence the type of ballast you need to properly run that fixture or lighting system. This starts with choosing between compact fluorescent or fluorescent lighting tubes.

This will also influence the required bulb type to:

  • One Pin
  • Two-Pins
  • T5
  • T12T18

From there you have to also consider the wattage, the tube length, and its basic shape, as well as the base type.

The Difference Between a Magnetic & Electronic Ballast

When deciding on the right type of ballast for your fluorescent lights, you also have to decide between magnetic or electronic.

For the most part, magnetic ballasts are considered obsolete in modern-day production lights. Though an office building, warehouse or older commercial space might still use magnetic ballasts in their fluorescent lighting systems. If you are simply maintaining the system on a budget, then a replacement magnetic ballast might make sense. Otherwise, your best option is to upgrade or install an electronic ballast.

Up-to-date electronic ballasts tend to be quieter, smaller, and lighter. They also don’t flicker, like older magnetic ballasts are prone to doing. This also means that electronic ballasts are more energy-efficient.

The Light Fixtures Starting Method

The starting method is also a critical factor when choosing a ballast for your fluorescent light fixtures. Some ballasts will cause the bulb to burn out prematurely for a particular type of light. The four most common types of fluorescent bulb starting methods are:

  • Preheat
  • Instant start
  • Rapid start
  • Programmed start

Preheat Start

A lot of preheat Start fluorescent light fixtures are only available with a magnetic ballast and often have a built-in starter. This outdated starting process sometimes takes several seconds to complete. Which is part of what caused magnetic ballasts to fall out of favor. It’s really the only viable option if you are maintaining the status quo with an older fluorescent lighting system.

Rapid Start

Rapid Staring systems are available for both magnetic and electronic ballasts. Though the magnetic equivalent tends to only be found in older commercial buildings. Most rapid-start ballasts use a low-voltage system to quickly preheat the filament to a specific temperature. At that point, the bulb itself starts to emit light. One of the benefits of a rapid start ballast is that it can increase lamp life by protecting it from a high-power surge in the beginning.

Instant Start

More modern Instant Start fixtures use an electronic ballast as it offers a higher initial voltage. This gets the fluorescent bulb to light and gradually warms up without prolonged delay.

Programmed Start

The most sophisticated type of starter method is Programmed Start, which you only find on electronic ballasts. They are essentially an updated version of a rapid start ballast which makes them better suited for use in fixtures that are turned on and off frequently. One of the biggest benefits of a programmed start ballast is that it offers energy-efficient lighting as well as increased lamp life with less risk of burnout.

Consider the Ballast Factor

The ballast factor is a specific rating used to indicate the strength with which the ballast drives the tube. Ideally, you want to choose a ballast factor that both optimizes the light output as well as maximizing energy savings. The typical ballast factor range is from 0.77 to as much as 1.1.

What Are Signs of a Bad Ballast?

If you’ve been having a problem with your fluorescent lights or one fixture that has been giving you trouble, your first suspicion should be a bad ballast. This is even more likely to be the case with a magnetic ballast, which tends to have a harsher effect on the fluorescent bulbs it supports.

Common symptoms of a bad ballast often include:

  • Delayed Starting
  • The Light Bulb Flickering
  • A Constant Buzzing Sound
  • Dimness or Low Output
  • Inconsistent Light Levels

The simplest way to determine if the problem is with the device, or the light bulb is to test the ballast with a multimeter or volt-ohm meter. The goal is to measure the electric current, as well as the voltage, and the following steps.

  • Step One: Turn off the power to the fluorescent light fixture.
  • Step Two: Carefully remove the casing of the light.
  • Step Three: Take out the fluorescent lightbulbs.
  • Step Four: Locate the ballast and use a screwdriver to remove it from the light fixture.
  • Step Five: Visually inspect the ballast. If it looks burned out, then it likely needs to be replaced.
  • Step Six: If you’re not sure, you can then set your multimeter to the ohm setting and insert the first probe of the multimeter into the wire connecting the red wires.
  • Step Seven: Touch the second probe to the green and yellow wires.

If the multimeter doesn’t give you a reading, then the ballast is dead and must be replaced before the fluorescent light can be safely turned on again.

If you do get a reading off the multimeter, it means that the ballast is good, and you might simply need to replace your fluorescent tube or other components of your lighting.

Can I Replace a Ballast Myself?

It is possible to replace a ballast yourself. Though it’s not always advisable. If you aren’t sure what type of ballast it is, or if it’s the correct one for that particular fixture, you could accidentally create an electrical fire hazard. When you weigh this risk against the small cost of having a professional electrician replace the ballast in one or more of your fluorescent lights at the same time, it’s a small price to pay.