Causes

Possible Solutions

The analog input gain and bias for the frequency reference input are set incorrectly.

Examine the gain and bias settings for the analog inputs that set the frequency reference.

  • Terminal A1: H3-03 [Terminal A1 Gain Setting], H3-04 [Terminal A1 Bias Setting]

  • Terminal A2: H3-11 [Terminal A2 Gain Setting], H3-12 [Terminal A2 Bias Setting]

  • Terminal A3: H3-07 [Terminal A3 Gain Setting], H3-08 [Terminal A3 Bias Setting]

The drive is receiving frequency bias signals from analog input terminals A1 to A3 and the sum of all signals makes the frequency reference.

  • Examine parameters H3-02, H3-10, H3-06 [MFAI Function Select]. If two or more of these parameters are set to 0, change the settings.

  • Use U1-13 to U1-15 [Terminal A1, A2, A3 Input Voltage] to make sure that the analog input values set to terminals A1, A2, and A3 are applicable.

The motor rotates faster than the frequency reference at low speed.

  • Decrease the value set in n4-70 [Speed Command Comp @ Low Freq] in increments of 0.1 Hz.

    Note:

    If you set the value too low, the motor can rotate in reverse.

  • Set E1-09 > 0 [Minimum Output Frequency].

    Note:

    • The recommended setting for E1-09 is 0.5 Hz.

    • When frequency reference < E1-09, the drive output will turn OFF.

PID control is enabled.

If PID control is not necessary, set b5-01 = 0 [PID Mode Setting = Disabled].

Note:

When PID control is enabled, the drive adjusts the output frequency as specified by the target value. The drive will only accelerate to the maximum output frequency set in E1-04 [Maximum Output Frequency] while PID control is active.