Master Electrician Exam (NEC)Services, Feeders, and Branch CircuitsHard
A master electrician is installing a new 100A, 120/240V, single-phase service for a dwelling unit. The service raceway is 1 1/4-inch PVC conduit. The service drop conductors are 2 AWG aluminum. What is the minimum vertical clearance required for the service drop conductors over a residential driveway that is not accessible to commercial vehicles?
- A12 feet
- B10 feet
- C15 feet
- D18 feet
Show answer & explanationAnswer & explanation
Correct answer: A. 12 feet
According to NEC 230.24(B)(2), the vertical clearance of service drop conductors over residential driveways and those commercial areas not subject to truck traffic shall be not less than 12 feet (3.66 m) for service-drop conductors exceeding 300V to ground, or 120/240V, 120/208V, 208Y/120V, 240/120V, 277/480V, 480Y/277V, or 600V to ground.
Why the other options are wrong
- B. 10 feet is for areas accessible to pedestrians only, not driveways.
- C. 15 feet is for areas accessible to trucks but not exceeding 14 feet in height.
- D. 18 feet is for areas accessible to trucks exceeding 14 feet in height, or public streets.
Service Drop Clearance (Residential Driveway)
The minimum vertical distance required for service drop conductors above a residential driveway not subject to commercial truck traffic, as specified in NEC 230.24(B)(2).
- Minimizes accidental contact.
- Specific clearances based on location and voltage.
- Refer to NEC 230.24(B).
Memory trick: Clearance: 'Driveway's Dozen' (12 feet) for 'No Trucks'!