Current-carrying service conductors must be:
- At least 8 AWG if copper, 6 AWG if aluminum [230.23(B)].
- Of sufficient ampacity to carry the load as calculated per Article 220 [230.23(A)].
- Of adequate mechanical strength [230.23(A)].
That last requirement seems redundant. If you’re using conductors of sufficient ampacity and permissible type, they will have adequate mechanical strength.
Important: Do a thoro