Single Phase: I = kW × 1000 / (V × PF × η) Three Phase: I = kW × 1000 / (√3 × V × PF × η)
7.5 kW 3-phase, 415V, PF=0.85, η=90%: I = 7500/(1.732×415×0.85×0.90) = 13.6 A
Frequently Asked Questions
FLA (Full Load Amperes) is the current drawn by a motor at rated load, voltage and frequency. It is the basis for selecting cable size, fuse, MCB and overload relay.
Induction motors draw 5–8× full load current during starting (DOL). This high inrush lasts 2–10 seconds. Star-delta and soft starters reduce this to 1.5–3× FLA.