Wire size depends on three main factors: current load (amps), circuit distance, and voltage drop requirements. Always size wire to handle 125% of the continuous load. Check for proper IP/NEMA ratings and material quality. Ensure safe placement: install in dry, accessible areas with good ventilation and at appropriate height (typically ~1. Practice good wiring: secure. Calculate the minimum wire gauge (AWG) for your electrical circuit based on amperage, voltage, distance, and conductor material. NEC compliant electrical wire sizing calculator for safe installations. three phase lines a, B and C (generally yellow, green and red), one zero line (light blue) and one ground line (yellow with green stripes).