For luminaires installed under metal-corrugates sheet roof decking, what is the minimum distance from the lowest surface of the roof decking to the top of the luminaire?

The minimum distance required from the lowest surface of the metal-corrugated sheet roof decking to the top of the luminaire is essential for ensuring safety and preventing overheating. A clearance of 1 ½ inches allows for adequate ventilation around the luminaire, which helps maintain its operating temperature. This distance is also designed to ensure compliance with electrical safety codes, minimizing the risk of electrical hazards such as short circuits or fire that may arise from insufficient spacing between electrical fixtures and structural elements.

Choosing a distance that is too small could lead to heat buildup, negatively impacting the performance and lifespan of the luminaire, as well as posing safety risks. Conversely, distances significantly larger than 1 ½ inches may not only be unnecessary but could also impact the aesthetic alignment and installation requirements of the fixtures. Thus, maintaining this specific clearance strikes a balance between operational safety and installation practicality.