New York State Master Electrician Practice Exam

What should be the minimum clearance for conductors above roofs of a building?

1. 3 feet

2. 10 feet

3. 12 feet

4. 18 feet

The correct answer is: 18 feet

The correct answer is based on the National Electrical Code (NEC), which provides clear guidelines regarding the minimum clearance of conductors above roofs to ensure safety and compliance. The NEC specifies that conductors must maintain a minimum vertical clearance of 18 feet above the roofs of buildings to prevent accidental contact, especially in areas where maintenance workers or other personnel may be operating. This distance helps to minimize the risk of electrical shock or other hazards that could arise from unintentional contact with power lines. It also takes into account the potentially varied environmental conditions that could affect clearances, such as snow accumulation or equipment placement on roofs. While other options may seem plausible, they do not meet the NEC requirements established to offer adequate protection and safety for both the electrical systems and the individuals working around them. Thus, 18 feet is established as the minimum clearance for conductors above roofs to ensure safety and compliance with the established standards.