Final Answer:
Fluorescent luminaires surface mounted on low-density fiberboard must have a minimum spacing of at least 3/8 inch from the fiberboard.
Step-by-step explanation:
When surface mounting fluorescent luminaires on low-density fiberboard, it is crucial to maintain proper spacing to prevent overheating and ensure safety. The National Electrical Code (NEC) specifies that these luminaires must be spaced at least 3/8 inch from the fiberboard surface. This requirement is designed to minimize the risk of heat buildup, reducing the potential for fire hazards. Proper spacing allows for adequate ventilation and dissipation of heat generated by the luminaires during operation. Compliance with these spacing regulations is essential for maintaining electrical safety standards and preventing potential fire risks associated with overheating.