The Jump frequency is a function that sets the dead band to a specified frequency band. If a machine that operated at constant speed is operated with variable speed, it can make resonance. To operate the machine without resonance from the natural frequency of the machinery mechanical system, use a frequency band jump.

You can program the drive to have three different Jump frequencies. Set d3-01 [Jump Frequency 1] to d3-03 [Jump Frequency 3] to the center value for the frequency to avoid and set d3-04 [Jump Frequency Width] to be 1/2 of the total band to avoid.

When you input a frequency reference that is the same as or near the Jump frequency width, the frequency reference changes automatically.

The drive accelerates or decelerates the motor smoothly until the frequency reference is not in the range of the Jump frequency band. The drive will use the active accel/decel time to go through the specified dead band range. If the frequency reference is not in the range of the Jump frequency band, switch to constant speed operation.

Figure 1. Jump Frequency
Note:

  • When you set Jump Frequencies 1 to 3, make sure that the parameters do not overlap. The drive will not indicate this condition.

  • When the drive is in the range of the Jump frequency, the frequency reference changes automatically. When the drive jumps frequencies, the output frequency changes smoothly as specified by the values set in C1-01 [Acceleration Time 1] and C1-02 [Deceleration Time 1].