What Is a Ballast?
A ballast is an electrical device that controls current through certain lamps, including fluorescent lamps. It also provides the electrical conditions needed to start the lamp. Inside a light fixture, the ballast works with the lamp to keep the light operating as intended.
Quick Facts About Ballast
- Category
- Lighting control component
- Used for
- Fluorescent and other discharge lamps
- Common confusion
- Lamp starter
- Also called
- Lighting Ballast, Lamp ballast
- Often discussed with
- Commercial Electrical Repair, Electrical Troubleshooting
Key Takeaways About Ballast
- Magnetic and electronic ballasts use different control methods.
- Lamp and ballast compatibility affects replacement choices.
- A ballast isn't the same part as a lamp starter.
How Ballast Works
A ballast manages the current that flows through a discharge lamp. The lamp produces light as current passes through gas inside its tube. Without current control, the lamp could draw too much current. Related service: Commercial Electrical Repair.
Related glossary terms: Light Fixture, Electrical Load, Electrical Short.
A magnetic ballast uses a coil to limit that current. An electronic ballast uses electronic parts to control the current. These designs can affect how a fixture starts and operates.
The ballast must match the lamp type and the fixture's electrical supply. Its label gives details that help identify a suitable replacement. Some fixtures also use a separate starter, while others handle starting within the ballast.
LED tubes come in different designs. Some work with a compatible ballast, while others need a fixture wired for direct power. The tube's instructions identify the intended setup.
From the Chris Miller Electric team
When we investigate a commercial fixture, we look beyond the ballast for the source of the problem. Our team checks the lamp and fixture connections as part of the diagnosis. We also use the ballast label to check replacement compatibility.
Ballast in Practice: A Real-World Example
A fluorescent fixture in a Fort Wayne shop stops lighting even after the lamp is changed. During a commercial electrical repair, an electrician checks the fixture and finds that its ballast needs replacement.
Related Terms
Light Fixture
A light fixture is an electrical device that holds or contains a light source and directs its light.
Electrical Load
Electrical load is the demand for electric power placed on a circuit or electrical system by connected equipment.
Electrical Short
An electrical short is a fault that lets current follow an unintended path with little resistance.
Chris Miller Electric
Have Questions About Ballast?
Contact Chris Miller Electric for practical guidance on Ballast and related 24 hour electrician work in Fort Wayne.