Motor No Load Current Calculator

Calculate no-load current for AC (Star/Delta) and DC motors

Motor No Load Current Calculator

Compliant with IEC 60034 Standards

Results:

No Load Current (A): 0.00

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How to Use the Calculator

Star Connection

  1. Enter the Motor Full Load Current in Amps.
  2. Select "Star Connection" from the dropdown.
  3. Click "Calculate" to get the no-load current.

Delta Connection

  1. Enter the Motor Full Load Current in Amps.
  2. Select "Delta Connection" from the dropdown.
  3. Click "Calculate" to get the no-load current.

DC Motor

  1. Enter the Motor Full Load Current in Amps.
  2. Select "DC Motor" from the dropdown.
  3. Click "Calculate" to get the no-load current.

No Load Current Fundamentals

AC Motor No Load Current

For AC motors, the no-load current is primarily the magnetizing current required to establish the magnetic field in the stator and rotor, plus a small component for core losses and friction/windage losses.

  • Star Connection: Typically lower no-load current due to higher impedance per phase.
  • Delta Connection: Higher no-load current compared to star, as each phase winding receives full line voltage.

DC Motor No Load Current

  • For DC motors, the no-load current is mainly consumed to overcome friction, windage, and core losses.
  • It's essential for assessing motor efficiency and identifying potential mechanical issues.

Key Formulas:

No load current at star connection = 0.1 × Motor Full load current

No load current at delta connection = 0.3 × Motor Full load current

No load current for DC motor = 0.25 × Motor Full load current

Calculation Formulas

Star Connection:
I_no_load = 0.1 × I_full_load

Delta Connection:
I_no_load = 0.3 × I_full_load

DC Motor:
I_no_load = 0.25 × I_full_load

Example Calculation

Motor Full Load Current: 100A

Star Connection:

No Load Current = 0.1 × 100A = 10A

Delta Connection:

No Load Current = 0.3 × 100A = 30A

DC Motor:

No Load Current = 0.25 × 100A = 25A

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