Part II of NEC Art. 230 provides the requirements for overhead service conductors. The bulk of Part II is devoted to clearances and supports. Part II starts off by requiring that all overhead service conductors be insulated or covered [230.22]. The next set of requirements is for the size and rating [230.23]. Some minimum sizes are specified, and the conductor ampacity must be sufficient for carrying the load, as calculated per Art. 220.
Overhead Service Conductors, Part 1
Know whether the conductors have adequate mechanical strength for the support provided for a given span.