Service-drop conductors shall have a minimum of ___ feet vertical clearance from final grade over residential property and driveways and commercial areas not subject to truck traffic where the voltage is limited to 300 volts to ground.

Service-drop conductors shall have a minimum of ___ feet vertical clearance from final grade over residential property and driveways and commercial areas not subject to truck traffic where the voltage is limited to 300 volts to ground.

• A. 10
• B. 12
• C. 15
• D. 18

Answer: (B)

Overhead service conductors must be kept high enough above the ground to prevent accidental contact and to allow for sag from heat, wind, and ice. For service-drop conductors with a voltage up to 300 volts to ground, the minimum vertical clearance above final grade over residential property and driveways and commercial areas not subject to truck traffic is 12 feet. This height provides a safe margin for people and typical activities while avoiding unnecessary height. If the area were subject to truck traffic, the minimum would be higher (18 feet) to accommodate tall vehicles. The other options don’t fit this scenario because 10 feet is too low for 300 V, 15 feet is higher than required for non-truck areas, and 18 feet applies to truck-traffic zones.

Overhead service conductors must be kept high enough above the ground to prevent accidental contact and to allow for sag from heat, wind, and ice. For service-drop conductors with a voltage up to 300 volts to ground, the minimum vertical clearance above final grade over residential property and driveways and commercial areas not subject to truck traffic is 12 feet. This height provides a safe margin for people and typical activities while avoiding unnecessary height. If the area were subject to truck traffic, the minimum would be higher (18 feet) to accommodate tall vehicles. The other options don’t fit this scenario because 10 feet is too low for 300 V, 15 feet is higher than required for non-truck areas, and 18 feet applies to truck-traffic zones.