For a 120/240-volt, 1Ø, 3-wire service, what is the minimum clearance required above the nearest point accessible to automobiles?

For a 120/240-volt, single-phase, three-wire service, the minimum clearance of 12 feet above the nearest point accessible to automobiles is specified due to safety concerns and to ensure that there is adequate space for vehicles to pass underneath without risking contact with the electrical service drop. This clearance is mandated by the National Electrical Safety Code (NESC) and local electrical codes to protect both the people operating vehicles and the integrity of the electrical infrastructure.

The intent of maintaining this minimum distance is to prevent accidental contact with the service conductors, which could result in electrical hazards such as shocks or short circuits. Additionally, it allows for variations in vehicle height and encourages safe practices in areas where vehicles might maneuver.

While other clearances may apply in different contexts, such as near roads or in certain types of installations, the specific requirement for 12 feet is crucial for this scenario to ensure compliance with safety regulations and to promote public safety around electrical installations.