Causes

Possible Solutions

The load is too heavy.

  • Decrease the load.

  • Increase the acceleration and deceleration times.

  • Examine the values set in L1-01 [Motor Overload (oL1) Protection], L1-02 [Motor Overload Protection Time], and E2-01 [Motor Rated Current (FLA)].

  • Use a larger motor.

    Note:

    The motor also has a short-term overload rating. Examine this rating carefully before setting drive parameters.

The motor is running continuously at a very low speed.

  • Change the run speed.

  • Use a drive-dedicated motor.

The drive is operating in a vector control mode, but Auto-Tuning has not been done.

  • Do Auto-Tuning.

  • Calculate motor parameter and set motor parameters.

  • Set A1-02 = 0 [Control Method Selection = V/f Control].

The voltage insulation between motor phases is not sufficient.

  • Use a motor with a voltage tolerance that is higher than the maximum voltage surge.

  • Use a drive-dedicated motor that is rated for use with AC drives for applications that use a motor on drives rated higher than 400 V class.

  • Install an AC reactor on the output side of the drive and set C6-02 = 1 [Carrier Frequency Selection = 2.0 kHz].

    Note:

    When the motor is connected to the drive output terminals U/T1, V/T2, and W/T3, surges occur between the drive switching and the motor coils. These surges can be three times the drive input power supply voltage (600 V for a 200 V class drive, 1200 V for a 400 V class drive).

The air around the motor is too hot.

  • Measure the ambient temperature.

  • Decrease the temperature in the area until it is in the specified temperature range.

The motor fan stopped or is clogged.

  • Clean the motor fan.

  • Make the drive environment better.