Feeder Sizing Basis
The wire size for a given ampacity is set in the Wire Ampacities command.
The default wire sizes are based upon NEC Table 310.16. These wire sizes are used when the wire size is chosen automatically. By default, the 60°C Copper column is used for wires up to #1, and the 75°C Copper column is used for wires 1/0 and larger.
Wire sizing adjustments due to ambient temperature are based upon NEC 310.15(B). The variable Ta in the equation is assumed to be 30.