What is a Ballast Light

What is a Ballast Light, and is it Really Necessary?

Ian Mutuli
Updated on

You may sometimes hear a fluorescent lamp buzzing and wonder what is happening there. That sound may be a result of a faulty ballast. Fluorescent lamps operated on ballasts may become dim or flicker when the ballast needs a replacement. So, what is a ballast light? It is a device that regulates the current flowing to the lamps in a lighting system. Keep reading ti more about

What is a Ballast?

A ballast is simply the functional part of a fluorescent or HID light source. It controls, regulates and stabilizes the light output of the fluorescent lamp. In addition, it ensures that the lamps stay lit by managing the distribution of energy in the fixture.

Ballasts come in different types and may need to provide a certain amount of energy to heat the fluorescent lamps. However, this is determined by the conditions your lighting system operates.

Types of Lighting Ballasts

There are different lighting ballasts, ranging from simple parts of the power loop to a more complex piece of the circuit. Some of these lighting ballasts are discussed below.

a). Standard Lighting Ballasts

Standard light ballasts enable the luminaire's basic, safe, and consistent operation and power circuit at lower power draw levels, switching on and in extended usage. Like the ones used in some LED or neon lamps, simple ballasts serve solely as a resistor, limiting the amount of current that passes through the light circuit.

b). Fluorescent Lighting Ballasts

When a lighting circuit relies on gas discharge, such as the ones found in many fluorescent light ballasts in the workplace, the luminaires to which it is connected require substantially more power in operation. This is because the ballast may serve as a reactance element on the inside circuit in these circuits.

This is required to allow for the voltage drop across a completed circuit without causing a runaway to rise the inflowing current, which would fast damage the lamp or the power supply that feeds it.

A fluorescent light may use either magnetic or electronic ballast. However, magnetic ballasts are outdated and only found in older lights as manufacturers no longer use them.

i). Magnetic Ballasts

A magnetic ballast is based on electromagnetic principles, which state that as an electrical current passes through a wire, it generates a magnetic pull around it.

A copper wire coil is contained in a magnetic ballast (also known as a choke). The magnetic field created by the wire retains the majority of the current, allowing only a small amount to reach the fluorescent light.

Depending on the length and thickness of the copper wire, this amount can change. This fluctuating flow of current is what causes your light to buzz or flicker from time to time.

Some magnetic ballasts require a starter since their design is less sophisticated than electronic ballasts.

ii). Electronic Ballasts

Ballasts can manage the current flowing through fluorescent lights with greater precision thanks to increasingly complex circuitry and components. They're smaller, lighter, and more efficient than magnetic equivalents, and they're less likely to generate flickering or buzzing sounds because they supply power at a much higher frequency.

c). LED Light Ballasts

LED light circuitry (and its related driver) is typically simple due to the LED lamp's low power draw, which is only a basic resistor to govern the flow of mains electricity through its circuitry. However, there are some things to consider when it comes to ballasts with LEDs, especially if you're upgrading by retrofitting LEDs into an old fixture or system.

How Does a Fluorescent Ballast Work?

Having seen the different types of ballasts, it is also important to know how they operate. For example, some electronic ballasts can explicitly modify the light output of your fluorescent or HID bulbs for dimming, and others can adjust to the conditions imposed on them.

The ballast must momentarily produce high voltage during lamp startup to establish an arc between the two lamp electrodes. The ballast lowers the voltage and regulates the electric current once the arc is generated, resulting in steady light output. The secret to a long bulb life is to keep the electrode temperature comfortable.

Magnetic ballasts control electrical current at a low cycle rate, resulting in apparent flicker. Low-frequency vibrations are also possible with magnetic ballasts. This source has an audible humming sound that people associate with fluorescent lighting.

Modern ballasts are designed with advanced electronics for more precise current flow through the electrical circuit. As a result, an electronic ballast does not produce a flicker or humming noise since it operates at a greater cycle rate.

Importance of Electronic Ballasts in Fluorescent Lamps

a). Saves Energy

The real benefit of electronic ballasts is that they consume less energy and save money. As a result of the lower power consumption, the ballast generates less heat, resulting in lower operating temperatures. In addition, the lights themselves work up to 10% more efficiently due to the reduced fixture temperatures and high-frequency operation; that is, the ballast factor improves.

b). Lamp Dimmability

The "dimmability" of full integrated circuit electronic ballasts is one of the most important qualities for future lighting system designs. Electronic ballasts can offer optimum power to the fluorescent lamp with the addition of light-level sensors to maintain a steady level of light as daylight grows and declines throughout the day.

Daylight dimming can save up to half the lighting energy in daylit perimeter zones. Dimming functions can also automatically raise or decrease light levels as the lights age or new lamps are fitted. In addition, because fluorescent lighting may be dimmed, light "control" is possible.

c). Reduced Flicker and Noise

Electronic ballasts are also advantageous in fluorescent lighting systems. Magnetic ballasts powered by a low frequency 60 Hz input can produce a distinctive flicker.

Flicker is eliminated with high-frequency ballasts.

Light flicker reduction enhances the overall light quality and can increase work performance1. Magnetic ballasts are also heavier than electronic ballasts. Finally, the magnetic ballast's characteristic hum is erased.

d). Increases Lamp Life

An electronic ballast operates at lower temperatures than a magnetic one. This increases lamp life and reduces general air conditioning and maintenance costs.

e). Provides Enough Voltage

When turning on the luminaire for the first time, make sure enough electricity is available. Allowing mains voltage to provide this first 'boost' once the user flips a switch allows enough current to leap across and complete an arc between the two electrodes in the lamp, resulting in light.

Know When to Replace Your Electrical Ballast

No matter how long your electronic ballast lasts, it will eventually need a replacement. So, you should know when it needs a replacement. Some of the signs you can look for include the following;

a). Does Your Light Need a Ballast?

Not all lamps use ballasts. Therefore, you need to be sure that your lights need a ballast. For example, LED bulbs, halogen, and incandescent bulbs do not use ballasts. In addition, there are other bulbs with integrated ballasts, which you cannot replace.

An internal ballast, for example, is found in many fluorescent bulbs. Compact fluorescent bulbs frequently have one built-in, as do some HID lights, although not always.

When single fluorescent tubes with an integrated ballast die or act erratically, they must be replaced like any other bulb. On the other hand, Larger light fixtures may require an external ballast.

b). Warning Signs

Some signs will let you know it's time to change the ballast. However, if only one fluorescent tube is out, you can replace it. Some of these signs include;

i). No Lights

If your bulbs aren't turning on, there's a good probability they've all gone out at the same time due to natural causes. On the other hand, your malfunctioning ballast likely burned them all out!

ii). Buzzing

If you hear a peculiar buzzing or humming noise coming from your bulbs or light fixture, your ballast is likely failing. It's fighting to keep the current flowing, generating audible voltage regulation issues. A failing ballast makes such noises, and that is enough warning.

iii). Changing Colors

There could be a problem with your lights if they take a long time to reach full brightness or if they strobe. In addition, ballasts that have been damaged by water or are malfunctioning have a hard time regulating current.

iv). Flickering/Dimming

Your lights should always be the same brightness and color. If you notice a change in hue, it's possible that your ballast is malfunctioning and sending varying voltage levels to your bulbs.

c). Check the ballast

You can check your ballast to examine if it has any obvious signs of needing a replacement.

i). Burn Masks

To see interior damage, you may need to shatter the ballast open. Also, replace the gadget if there are burn marks inside or on the wires. This is because it was unable to handle the current and became overloaded. If this is the case, your bulbs may need to be replaced as well.

ii). Leaking Oil

If you have the traditional magnetic ballast, it may leak oil and malfunction. This calls for an immediate replacement. You will also need to clean the area before replacing the lighting ballast.

iii). Water Damage

If you see water inside the ballast or in the panel, you can be sure that it caused damage to your ballast; this will force you to replace it.

iv). Swollen Casing

This is something you'll notice even before removing the casing cover. If the plastic on your ballast is bulging, it's time to replace it. Energy most likely overloaded it, causing harm to the box.

Meeting Energy Reduction Requirements on Lights that Require a Ballast

Dimmable ballast for energy efficiency

There are some efficient options through which you can use ballast-dependent lights. LED lights may be a good option in some scenarios, but you may need a light bulb that uses a ballast in others. You can consume energy efficiently by using;

a). Dimmable Ballasts

When combined with the appropriate controls, a dimmable ballast can allow you to alter light output according to the conditions seamlessly. According to a 2010 study, dimming controls for fluorescent lamps are an important feature

b). Multiple Ballasts

The light output of multi-lamp fixtures is controlled by two or more different ballasts working together. If you only need to turn off 50% of the bulbs in a single fixture, this solution is a cost-effective and easy-to-install option.

c). Low Ballast Factor

If you want to save energy but don't need precise lighting control, a low ballast factor device could be a good option. These low-cost solutions reduce a lamp's advertised wattage by 10% to 15% when turned on.

Frequently Asked Questions About Ballast Lights

1. Can I replace a ballast myself?

Yes, if you have some technical knowledge; but, if you're hesitant, it's advisable to hire an electrician to do it for you because it's a difficult job. In addition, cheaper ballasts will almost certainly necessitate more rewiring than a fitting with a branded ballast. Therefore, it's worth paying a little more now to save money and time later.

Branded ballasts can last a long time, so once you replace one, you won't have to replace it again for at least 10 years.

2. What causes fluorescent lights to flicker?

The ballast in your lighting system controls the current flowing to the fluorescent light and supplies the voltage required to turn them on. The ballast is a device that takes in electricity and then regulates the current flowing through the bulbs. This is why a degrading fluorescent ballast will cause the lights to flicker.

Ian Mutuli

About the author

Ian Mutuli

Founder and Managing Editor of Archute. He is also a graduate architect from The University of Nairobi, Kenya.