Cable Rating And Derating Factor Site

Using NEC method for 90°C cable at 55°C ambient: $K_temp = 0.71$ (from table above)

$$I_adjusted = I_standard \times F_total$$ cable rating and derating factor

$$I_actual = I_base \times K_1 \times K_2 \times K_3 \times K_4 \times K_5$$ Using NEC method for 90°C cable at 55°C

Always design with derating first, voltage drop second, and mechanical strength third. When in doubt, measure the real-world conditions and consult the latest NEC or IEC tables. voltage drop second