Derating Calculator ((install)) -

7 total conductors (you + 6 others) → factor of 0.70 (from NEC Table 310.15(C)(1)).

Download a trusted derating app (e.g., Southwire’s Conduit Fill & Derating, or ETAP’s cable calculator) and always verify your results against the latest NEC or local electrical code. Your safety—and your equipment’s lifespan—depends on it. derating calculator

You need to run 10 AWG copper wire (rated 30A at 30°C) through a conduit in a 50°C ambient environment. The conduit will contain 6 other current-carrying wires. 7 total conductors (you + 6 others) → factor of 0

30 A × 0.80 (temp) × 0.70 (bundling) = 16.8 amps . Southwire’s Conduit Fill & Derating

For 50°C ambient with 90°C wire: Many tables show a factor of 0.80 .