Enter your Motor Voltage, Phase, Power Rating, Power Factor (cos φ), and Motor Efficiency to calculate the Full Load Amps (FLA) your motor draws at peak load — along with Power (kW) and Apparent Power (kVA) so you can size wiring, fuses, and protection devices with confidence.
Full Load Amps (FLA)
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Power (kW)
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Apparent Power (kVA)
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Full Load Amperage (FLA) is the amount of current a motor draws when operating at its rated load and voltage. It's determined through laboratory testing and is typically shown on the motor nameplate.
For 3-phase motors: I = P / (√3 × V × cos φ × η). For single-phase motors: I = P / (V × cos φ × η). The √3 factor accounts for the three-phase power distribution.
FLA (Full Load Amps) is the maximum current at rated load, while RLA (Running Load Amps) is the actual current during normal operation. FLA is typically RLA plus a safety margin of about 25%.
Power factor represents the phase relationship between voltage and current in AC circuits. Motors typically have power factors between 0.8-0.9, affecting the actual current draw and efficiency calculations.
Motor nameplates show voltage, current (FLA), power rating, phase, frequency, power factor, and efficiency. These values are essential for accurate amperage calculations and proper circuit protection sizing.
Modern motors typically have efficiencies between 90-96%. Older motors may be 85-90%. Premium efficiency motors can reach 96%+ efficiency. Check the nameplate or manufacturer specifications for exact values.
Motor amperage is inversely proportional to voltage. Higher voltage results in lower current for the same power output, which is why industrial applications often use higher voltages to reduce current and conductor sizes.