Rockwell Automation GV3000/SE AC Gen. Purpose and Vector Drive Software Start-Up and Ref. Manual - Manual (Page 146)

4-60 GV3000/SE AC Drive Software Reference, Version 6.06
.
With DC braking enabled (H.005 = ON), braking will be activated after a stop
command when the decelerating drive reaches a speed corresponding to DC Braking
Start Frequency (H.006). The braking period ends after the programmed time
regardless of the actual motor speed. The value should be set to a level that avoids
activation at rest.
Operating a motor continuously at a particular frequency may cause vibrational
resonance within some machines. Three independent parameter pairs can be
configured for avoidance frequency and frequency band to prevent motor vibration by
preventing the drive output frequency from operating within the selected band(s).
Refer to figure 4.12.
The actual avoidance frequency selection is limited by Minimum Speed (P.003) and
Maximum Speed (P.004). Normal acceleration and deceleration is not affected by this
function.
H.008 DC Braking Time
This parameter sets
the time period for
which DC braking will
be applied.
Parameter Range: 0.1 to 20.0 seconds
Default Setting: 3.0
Parameter Type: Tunable
Refer also to parameters: H.005 DC Braking Enable
H.006 DC Braking Start Frequency
H.007 DC Braking Current
H.009 Avoidance Frequency Enable
This parameter
enables the
avoidance frequency
bands selected in
H.011, H.013, and
H.015.
Parameter Range: OFF = Disable avoidance frequency processing
ON = Enable avoidance frequency processing
Default Setting: OFF
Parameter Type: Tunable
Refer also to parameters: P.003 Minimum Speed
P.004 Maximum Speed
H.010 to H.015 Avoidance Frequency Midpoint and
Band 1, 2, and 3