Where is thermal protection required for a ballast of a fluorescent luminaire?

Thermal protection for a ballast of a fluorescent luminaire is required indoors due to the potential for overheating within enclosed spaces. Indoor environments can experience various factors like poor ventilation or being situated in confined spaces, which can lead to accumulation of heat around the ballast. Adequate thermal protection ensures that the ballast does not reach temperatures that could compromise its functionality or safety.

While outdoor, basement, and attic locations may present their own challenges, the indoor environment is typically where the risk of overheating due to the combination of electrical load and the thermal characteristics of the space is most pronounced. Indoor installations are subject to building codes and safety regulations that mandate thermal protection features to safeguard both the luminaire and the occupants of the space.