A light ballast is a device that regulates the electrical current going to certain types of light fixtures, most commonly fluorescent and HID (high-intensity discharge) lighting. Its job is to provide the proper starting voltage and then limit the current to prevent the light from overheating or failing.

If a ballast is failing, you may notice flickering lights, buzzing or humming sounds, delayed startup, dim lighting, or lights that won’t turn on at all. In many cases, upgrading to modern LED fixtures eliminates the need for a ballast altogether, improving energy efficiency and reducing maintenance.

If you’re experiencing lighting issues or aren’t sure whether your fixture uses a ballast, a licensed electrician can inspect the system and recommend repair or replacement options.