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A VFD is sized on current, not motor kilowatts, because it must supply the motor's actual full load current plus the overload the application needs. Above 40 degrees C ambient most drives derate about 2% per degree, and switching frequency above the default derates them further.
VFD sizing
drive current >= motor FLC / ambient derating; overload capability >= FLC x required overload
Because kW ratings assume a standard 4-pole motor at a standard power factor. High-pole-count, high-slip or older motors draw more current for the same kW.
110% for pumps and fans (variable torque), 150% for conveyors and positive displacement pumps, and up to 200% for high-breakaway loads.