[ VD = \sqrt3 \times K \times I \times L / A ]

#1/0 AWG: 0.98 ohms/1000 ft → R = 0.29 ohms → VD = 5.8V (4.8%) – acceptable.

[ VD = 2 \times K \times I \times L / A ]

: 120V single-phase, 20A load, 150 ft one-way, copper, target VD <3% (3.6V).

[ R = \rho \fracLA ]