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E4 Help Desk

Commissioning a Permanent Magnet Motor

Note

This guide covers information related to Permanent Magnet Motors only.

Before commissioning, ensure that :

  • The drive has been mechanically and electrically installed.

  • A Control Source and Speed reference source has been selected. !!!!!(Insert link here to landing page for control and speed sources)!!

Caution

The phase-to-phase back EMF (RMS) voltage must not exceed the applied AC supply voltage, Exceeding this limit may result in drive damage.

Ideally the motor Back EMF should be =/> 1 V / Hz, lower values may reduce low speed performance.

Maximum motor frequency 360Hz

Operation down to 10% of rated speed is typically possible. Performance may be reduced at lower speeds or when using motors with a low back EMF-to-frequency ratio.

Commissioning Procedure

  1. Obtain the motor back EMF from the motor nameplate, datasheet or motor manufacturer and enter it into P-07.

    Note

    Enter the phase-to-phase RMS back EMF at rated motor speed/frequency. Do not enter the motor rated voltage.

  2. Select Motor Control Mode

    Set P-51= 2 (Permanent Magnet Motor Control)

  3. Enter Motor Nameplate data

    Parameter

    Description

    P-08

    Rated Motor Current

    P-09

    Rated Motor Frequency

    P-10

    Rated Motor Speed (Optional)

  4. Run Autotune

    Set :

    P-52 > 1

    The autotune will start immediately and the display will show:

    Auto-t

    Caution

    The drive output will be enabled during the autotune process and the motor shaft may rotate. Ensure that it is safe to proceed before starting the autotune.

    Once the autotune is complete, the display will return to Stop.

  5. Run the Motor

    The motor can now be operated using the selected control source and speed reference.

Further Optimisation

Starting Performance

Several boost parameters are available to optimise starting, low-speed, and stopping performance.

Troubleshooting and FAQ's

Question

Answer/Solution

What measurements are taken during Autotune?

During Autotune, the drive measures and populates: P-56 Motor Stator Inductance (Lsd) and P-57 Motor Stator Inductance (Lsq).

Suitable Motor Types

Surface-mounted permanent magnet motors and Interior permanent magnet motors

Autotune Requirements

Motor must be unloaded where possible

Motor must be at standstill before starting

Correct motor data must be entered before autotune

Motor Will Not Start

  • Verify P-51 = 2 (Permanent Magnet Motor mode).

  • Check that the motor back EMF has been entered correctly in P-07.

  • Confirm the value entered is the phase-to-phase RMS back EMF, not the rated motor voltage.

  • Verify motor nameplate data has been entered:

    P-08 Motor Rated Current

    P-09 Motor Rated Frequency

    P-10 Motor Rated Speed (if available)

  • Confirm the drive has a valid Run Command.

  • Confirm a valid Speed Reference has been selected. Check for active drive faults or warnings.

Autotune Fails

  • Verify P-51 = 2 (Permanent Magnet Motor mode).

  • Verify the motor nameplate data is correctly entered.

Poor Low-Speed Performance

  • Check that:

  • P-56 Motor Stator Inductance (Lsd) has been populated.

  • P-57 Motor Stator Inductance (Lsq) has been populated.

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