5.8 n: Special AdjustmentsThe n parameters handle a variety of specialized adjustments and functions, including Hunting Prevention.u n1: Hunting PreventionHunting Prevention keeps the drive from hunting as a result of low inertia and operating with light load.n n1-02: Hunting Prevention Gain SettingSets the gain for the Hunting Prevention Function.No. Name Setting Range Defaultn1-02 Hunting Prevention Gain Setting 0.00 to 2.50 1.00Normally, n1-02 does not need to be changed, but adjustment may help under the following conditions:• If the motor vibrates while lightly loaded increase the gain by 0.1 until vibration ceases.• If the motor stalls decrease the gain by 0.1 until the stalling ceases.u n3: Overexcitation DecelerationOverexcitation deceleration increases the flux during deceleration and allows shorter deceleration time settings than withnormal deceleration without the use of a braking resistor. Enabled by setting L3-04 = 4.Notes on Overexcitation Deceleration• As regenerative energy is mainly dissipated as heat in the motor, the motor temperature will rise if overexcitation decelerationis applied frequently. In such cases, make sure the motor temperature does not exceed the maximum allowable value orconsider using a braking resistor option instead.• The drive decelerates at the active deceleration time. Make sure to set this time so that no overvoltage (ov) fault occurs.• When a Run command is entered during overexcitation deceleration, overexcitation operation is cancelled and the drive willreaccelerate to the specified speed.• Do not use overexcitation deceleration in combination with a braking resistor option.Use parameter n3-13 for adjusting overexcitation deceleration.n n3-13: Overexcitation Deceleration GainApplies a gain to the V/f pattern output value during overexcitation deceleration, thereby determining the level ofoverexcitation. The drive returns to the normal V/f value after the motor has stopped or when it is accelerating to the frequencyreference.No. Name Setting Range Defaultn3-13 Overexcitation Deceleration Gain 1.00 to 1.40 1.10The optimum setting for n3-13 depends on the motor flux saturation characteristics.• Increase the gain by 1.25 to 1.30 to improve the breaking power of overexcitation.• Reduce the value when the motor slip gets too high, which can trigger overcurrent (oC), motor overload (oL1), or driveoverload (oL2) faults.5.8 n: Special AdjustmentsYASKAWA ELECTRIC SIEP C710606 31B YASKAWA AC Drive – J1000 Technical Manual 1215 Parameter Detailshttp://nicontrols.com
