What is the recommended minimum clearance above a flat roof for overhead conductors?

The recommended minimum clearance above a flat roof for overhead conductors is 18 feet. This clearance is outlined in the National Electrical Code (NEC) to ensure safety and proper functioning of electrical systems. Overhead conductors must be elevated sufficiently to prevent accidental contact and to minimize risks during maintenance activities or potential physical disturbances like snow accumulation or other weather conditions.

Maintaining an 18-foot clearance allows for safe access for workers and equipment, reducing the chance of electrical hazards. This distance also helps safeguard the wiring against potential obstructions and environmental factors, ensuring that the conductors remain reliable and effective under various conditions.