Yaskawa AC Drive P1000 Bypass Technical Manual - Manual (Page 139)

5.9 n: Special Adjustments
These parameters control a variety of specialized adjustments and functions, including Hunting Prevention and High Slip
Braking.
u n1: Hunting Prevention
Hunting Prevention prevents the drive from hunting as a result of low inertia and operating with light load. Hunting often
occurs with a high carrier frequency and an output frequency below 30 Hz.
n n1-01: Hunting Prevention Selection
Enables or disables the Hunting Prevention function.
Note: This function is available only when using V/f Control. Disable Hunting Prevention when drive response is more important than suppressing
motor oscillation. This function may be disabled without problems in applications with high inertia loads or relatively heavy loads.
No. Name Setting Range Default
n1-01 Hunting Prevention Selection 0, 1 1
Setting 0: Disabled
Setting 1: Enabled
n n1-02: Hunting Prevention Gain Setting
Sets the gain for the Hunting Prevention Function.
No. Name Setting Range Default
n1-02 Hunting Prevention Gain Setting 0.00 to 2.50 1.00
Although this parameter rarely needs to be changed, it may require adjustment in the following situations:
• If the motor vibrates while lightly loaded and n1-01 = 1, increase the gain by 0.1 until vibration ceases.
• If the motor stalls while n1-01 = 1, decrease the gain by 0.1 until the stalling ceases.
u n3: High Slip Braking (HSB) and Overexcitation Braking
n High Slip Braking (V/f)
HSB works in V/f Control only and decreases the stopping time compared to normal deceleration without using dynamic
braking options. HSB reduces the output frequency in large steps to stop the motor and produce a high slip, which dissipates
the regenerative energy created from decelerating the load in the motor windings. Due to the increased temperature of the
motor windings, do not use HSB to frequently stop the motor. The duty cycle should be around 5% or lower.
Notes on Using High Slip Braking
• The set deceleration time is ignored during HSB. Use Overexcitation Deceleration 1 (L3-04 = 4) to stop the motor within a
specified time.
• Braking time varies based on the load inertia and motor characteristics.
• Enabling HSB and KEB Ride-Thru simultaneously will trigger an oPE03 error.
• HSB must be triggered by a digital input set to H1-oo = 68. After the HSB command is given, the drive will not restart
until the motor is completely stopped and the Run command is cycled.
• Use parameters n3-01 through n3-04 to adjust HSB.
n n3-04: High Slip Braking Overload Time
Sets the time required for an HSB overload fault (oL7) to occur when the drive output frequency does not change during an
HSB stop due to excessive load inertia or the load rotating the motor. To protect the motor from overheat, the drive trips with
an oL7 fault if these conditions last longer than the time set in n3-04.
No. Name Setting Range Default
n3-04 High Slip Braking Overload Time 30 to 1200 s 40 s
5.9 n: Special Adjustments
YASKAWA SIEP YAIP1B 01A YASKAWA AC Drive – P1000 Bypass Technical Manual 139
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Programming