Calculated estimate8 AWG
voltage-drop basis
Next common copper size by resistance model
Required conductor area14,333 circular mils
Allowed drop3.6 V
Modeled drop with 8 AWG3.13 V
Modeled drop percentage2.6%
Voltage drop is only one conductor-sizing check. A qualified electrician must separately verify allowable ampacity, temperature and terminal ratings, insulation, installation method, adjustment factors, overcurrent protection, fault duty, neutral loading, and the adopted code.