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n5-02: Motor Inertia Acceleration Time

No.

(Hex.)

Name

Description

Default

(Range)

n5-02

(05B1)

Motor Inertia Acceleration Time

Sets the length of time for the motor to accelerate from the stopped to the maximum frequency with a single motor at the rated torque. Inertia Tuning automatically sets the motor acceleration time.

Determined by C6-01, E5-01, and o2-04

(0.001 - 10.000 s)

If you cannot do Inertia Tuning, calculate the motor acceleration time as shown here or measure the motor acceleration time and set n5-02 to this value.

Calculate the Motor Acceleration Time

Use this formula to find the motor acceleration time:

  • JMotor = Moment of inertia of motor (kg m2)

  • nrated = Motor rated speed (min-1, r/min)

  • Trated = Motor rated torque (N m)

You can also use this formula to find the motor acceleration time:

  • frated = Motor rated frequency (Hz)

  • P = Number of motor poles

Calculate the Motor Acceleration Time

Use this procedure to calculate the motor acceleration time:

  1. Use A1-02 [Control Method Selection] to set the control method.

  2. Disconnect the motor and load.

  3. Run Auto-Tuning to set motor parameters.

    When you cannot do Auto-Tuning, manually set motor parameters with the information on the motor nameplate or test reports. Set the E2 parameters for induction motors. Set the E5 parameters for PM motors.

  4. Set C5 parameters [Automatic Speed Regulator (ASR)].

  5. Set C1-01 [Acceleration Time 1] = 0.

  6. Set L7-01 [Forward Torque Limit] to 100%.

  7. Set the frequency reference to the same value as the motor rated speed.

  8. Measure the length of time for the motor to reach the rated speed.

    Show U1-05 [Motor Speed] on the keypad and enter the Run command (forward run).

  9. Stop the motor.

  10. Set n5-02 to the measured motor acceleration time value.

Reset all of the parameters that you changed to the previous setting values.