Journeyman Electrician Exam (NEC)Wiring Methods and MaterialsMedium
A journeyman electrician is installing a temporary power pole for a construction site. The overhead conductors from the utility drop will be attached to the pole. What is the minimum clearance required for these service drop conductors above a public street, alley, or public road, that is subject to truck traffic?
- A18 feet
- B19 feet
- C15.5 feet
- D12 feet
Show answer & explanationAnswer & explanation
Correct answer: A. 18 feet
According to NEC Table 230.9, for service drop conductors not over 600 volts, the minimum clearance above public streets, alleys, roads, or parking areas subject to truck traffic is 18 feet.
Why the other options are wrong
- B. Incorrect. 19 feet is not a standard minimum clearance specified in NEC Table 230.9 for this scenario.
- C. Incorrect. 15.5 feet is the minimum clearance over residential driveways and commercial areas not subject to truck traffic.
- D. Incorrect. 12 feet is the minimum clearance over areas accessible to pedestrians only.
Service Drop Clearances
NEC Article 230 specifies minimum clearances for overhead service drop conductors from various surfaces and structures to ensure safety.
- Clearances vary based on the voltage and the type of area (pedestrian, residential driveway, public street, etc.).
- These clearances prevent accidental contact with vehicles, equipment, or people.
- Table 230.9 (now 230.24(B) and 230.24(D) in newer codes) details these requirements.
Memory trick: Clear the way, or a truck might sway!