1363.03 INSULATION OF CONDUCTORS.
All metallic conductors forming parts of such current-carrying electric circuits shall be insulated from the ground wherever practicable or if, in the case of any particular metallic conductors such insulation shall be impracticable, then particular metallic conductors which cannot be insulated shall be constructed and maintained to afford as high a resistance to the ground as practicable.
(1979 Code 91.72)