Electrician's Licensing Practice Exam

In electrical installations, what is the minimum clearance above finished grade for overhead service drops?

1. 10 ft

2. 12 ft

3. 15 ft

4. 8 ft

The correct answer is: 12 ft

In electrical installations, the minimum clearance above finished grade for overhead service drops is 12 feet. This standard is essential for ensuring safety and accessibility. The required height helps to prevent accidental contact with the electrical conductors, which could result in severe electrical hazards, especially in areas where vehicles or pedestrians may come into contact with the overhead lines. Public safety is a primary concern in electrical installations. Maintaining a clearance of 12 feet ensures that there is ample space above structures, vehicles, and people, reducing the risk of electrical accidents. For example, if the service drop crosses over a driveway or a walkway, this height minimizes the chances of the wire being inadvertently struck by tall vehicles or equipment, as well as reducing the risk for individuals standing beneath. The other heights listed—10, 15, and 8 feet—either do not comply with the national electrical codes or do not provide adequate safety margins for typical installation environments. Specifically, 10 feet would be too low for many applications, especially in areas where larger vehicles are present. Conversely, while 15 feet provides an extra margin of safety, it exceeds the minimum requirement and may not be necessary for many residential applications, leading to potential inefficiencies or unnecessary costs in installation. An 8-foot clearance