BASIC NEC CODE RULES AND DESIGN PRACTICE

Load: Unit Heater 10 KW, 230V, 3 phase, find I, wire size, circuit breaker size. Conduit Size. I = 10 KW = 25.1 Amp .23 KV (3. Wire Size- 25.1A = 31.3 Amp.8 NEC 310-16 Use #8 good for 45 amp, 3 #8 + 1 #8 ground in 1" RGC Table 3A . Circuit Breaker = 25.1A = 31.3 Amp so use 35A.8 Conduit Size if different size wires are used ................
................