Star Delta Motor Current Calculator

Calculate motor full load, star, and delta currents for 3-phase AC motors

Star Delta Motor Current Calculator

Compliant with IEC 60034 Standards

Results:

Motor Full Load Current (A): 0.00

Delta Current (A): 0.00

Star Current (A): 0.00

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How to Use the Calculator

3-Phase AC Motor Current Calculation

  1. Enter the motor's power (in kW or HP).
  2. Enter the system voltage in Volts.
  3. Input the power factor (PF) (typically 0.8 for motors).
  4. The calculator will first determine the Motor Full Load Current (FLC).
  5. Then, it will calculate the Delta Current (58% of FLC) and Star Current (33% of FLC).

Motor Current Fundamentals

Motor Full Load Current (FLC)

The Full Load Current (FLC) is the current drawn by the motor when operating at its rated power output and voltage.

  • FLC is crucial for sizing protective devices and cables.
  • It depends on motor power, voltage, and power factor (efficiency is assumed in standard calculations).

Star Delta Currents

Star-Delta (Y-Δ) starters are used to reduce the starting current of induction motors. This applies to 3-phase AC motors.

  • Delta Current: The current drawn by the motor when connected in Delta (Δ). It is 58% of the motor's FLC.
  • Star Current: The current drawn by the motor when connected in Star (Y). It is 33% of the motor's FLC, providing a reduced starting current.

Key Formulas:

AC Three Phase FLC (A) = (Power (W)) / (√3 × Voltage (V) × PF)

Delta Current (A) = FLC (A) × 0.58

Star Current (A) = FLC (A) × 0.33

Calculation Formulas

Motor Full Load Current (FLC):

AC Three Phase:
I_FLC = (P_W) / (√3 × V × PF)


Star Delta Currents:

Delta Current (A):
I_delta = I_FLC × 0.58

Star Current (A):
I_star = I_FLC × 0.33

Example Calculation (3-Phase AC Motor):

Power: 10 kW

Voltage: 400V

PF: 0.85

FLC = (10 * 1000) / (√3 * 400 * 0.85) ≈ 16.98 A

Delta Current = 16.98 A × 0.58 ≈ 9.85 A

Star Current = 16.98 A × 0.33 ≈ 5.60 A

Results: FLC = 16.98A | Delta = 9.85A | Star = 5.60A

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