Delta VFD-BW Series, User Manual

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Chapter 5 Parameters
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VFD-BW Series
Revision May 2009, BWE0, SW V1.05 5-37
With Auto acceleration / deceleration it is possible to reduce vibration and shocks during
starting/stopping the load.
During Auto acceleration the torque is automatically measured and the drive will accelerate to
the set frequency with the fastest acceleration time and the smoothest start current.
During Auto deceleration, regenerative energy is measured and the motor is smoothly stopped
with the fastest deceleration time.
But when this parameter is set to 04, the actual accel/decel time will be equal to or more than
parameter Pr.01-09 to Pr.01-12 and Pr.01-18 to Pr.01-21.
Auto acceleration/deceleration makes the complicated processes of tuning unnecessary. It
makes operation efficient and saves energy by acceleration without stall and deceleration
without brake resistor.
In applications with brake resistor or brake unit, Auto deceleration shall not be used.
01 - 16 Acceleration S-Curve
01 - 17 Deceleration S-Curve
Factory Setting: 00
Settings 00 S-curve disabled
01 to 07 S-curve enabled (07 is smoothest)
This parameter is used to ensure smooth acceleration and deceleration via S-curve.
The S-curve is disabled when set to 00 and enabled when set to 01 to 07.
Setting 01 gives the quickest and setting 07 the longest and smoothest S-curve.
The AC motor drive will not follow the Accel/Decel Times in Pr.01-09 to Pr.01-12 and Pr.01-18
to Pr.01-21 when S-curve is enabled.
The diagram below shows that the original setting of the Accel/Decel Time is only for reference
when the S-curve is enabled. The actual Accel/Decel Time depends on the selected S-curve
(01 to 07).
3
1
2
4
1
3
4
2
1 2
Disable S curve
3 4
Enable S curve
Acceleration/deceleration Characteristics