Calculadora de Corriente de Arranque de Motor Gratis
Calcula la corriente de arranque de motores eléctricos y el impacto en el sistema de alimentación.
DOL=6-8x, Soft start=2-3x, VFD=1-1.5x
Full Load Current (FLA)
11.7 A
Full Load Current (FLA) vs Motor Horsepower
Fórmula
## Motor Starting Current Electric motors draw significantly more current during startup than at full speed. This inrush can be 6-8 times the full-load current. ### Formulas **FLA (3-phase) = HP x 746 / (sqrt(3) x V x Eff x PF)** **Starting Current = FLA x Multiplier** ### Starting Methods and Multipliers - Direct-On-Line (DOL): 6-8x FLA - Star-Delta: 2-3x (reduced torque) - Soft Starter: 2-4x (adjustable) - VFD: 1-1.5x (best control)
Ejemplo Resuelto
10 HP motor, 480 V 3-phase, 90% efficient, PF 0.85, DOL start (6x).
- 01Motor watts: 10 x 746 = 7,460 W
- 02FLA: 7460 / (1.732 x 480 x 0.90 x 0.85) = 7460 / 635.6 = 11.7 A
- 03Starting current: 11.7 x 6 = 70.4 A
- 04Starting kVA: 70.4 x 1.732 x 480 / 1000 = 58.5 kVA
Preguntas Frecuentes
Why is starting current so high?
At standstill, the motor's back-EMF is zero, so impedance is very low. As the motor accelerates, back-EMF rises and current drops to normal.
How does inrush affect the electrical system?
Large inrush can cause voltage dips, nuisance breaker trips, and flicker. Size feeders and breakers for the starting current.
When should I use a soft starter or VFD?
For motors above 10 HP on weak supplies, frequent starts, or when gradual acceleration is beneficial for the driven equipment.
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