Which of the following ballasts are required to have thermal protection?

  1. The ballast of a fluorescent luminaire installed indoors, including a replacement ballast for this type of luminaire
  2. A simple reactance ballast in a fluorescent luminaire with straight tubular lamps
  3. A ballast in a fluorescent exit luminaire
  4. A ballast in a fluorescent luminaire used for egress lighting, and energized only during a failure of the normal supply
  5. All of the above

Answer: A

The special provisions for electric-discharge lighting systems of 1,000V or less can be found in Part XII of Art. 410. As noted in 410.130(E), "The ballast of a fluorescent luminaire installed indoors shall have integral thermal protection. Replacement ballasts shall also have thermal protection integral with the ballast."

A simple reactance ballast in a fluorescent luminaire with straight tubular lamps, a ballast in a fluorescent exit luminaire, and a ballast in a fluorescent luminaire used for egress lighting and energized only during a failure of the normal supply are not required to have thermal protection.

Owen is the owner and president of National Code Seminars and the holder of master electrician certifications in 46 states. He can be reached at necexpert@aol.com.