How long of overhead service conductors operating at less than 300 V is permitted with 18" of clearance above the roof?

The correct answer reflects the regulations surrounding the clearance requirements for overhead service conductors. When overhead service conductors operate at less than 300 volts, there are specific guidelines that ensure safety and accessibility in relation to buildings and structures.

In this context, if there is 18 inches of clearance above the roof, the permitted length for overhead service conductors in such a situation is 6 feet. This requirement is intended to prevent any potential hazards caused by electrical lines coming into close proximity with rooftops, where maintenance activities might occur or where people may be present.

It's important to adhere to these standards as they are designed to ensure safety for both the occupants of the building and for anyone working on or around the roof area. Maintaining the appropriate clearance helps to minimize the risk of accidental contact and electrical hazards.

Understanding these regulations is crucial for anyone working in the field, as it ensures compliance with safety standards and regulations in electrical installations.