Introduction Parameter x.00
Parameter
description format
Keypad and
display
CT Modbus
RTU
User
programming
CT Soft Menu 0
Advanced parameter
descriptions
Menu 2
Commander SK Advanced User Guide 35
Issue Number: 2 www.controltechniques.com
Figure 9-8
In modes 0 and 1 the motor voltage is correctly set according to the motor rated voltage parameter, while in modes 2 and 3 the motor voltage is
allowed to go up to a factor of 1.2 times its normal value during deceleration. This higher voltage saturates the motor which increases the losses in the
motor and therefore reduces the amount of energy transferring from the motor to the DC bus for a given deceleration rate. For a given amount of
energy being dissipated by the drive at the regulated DC bus level, modes 2 and 3 will allow a faster deceleration than modes 0 and 1, providing that
the motor can stand the extra losses being dissipated in it.
Mode 0 is normally selected when using a braking resistor (mode 3 can be selected if desired but will cause the motor to heat up more due to the
higher losses in the motor when compared to mode 0)
0: S ramp disabled
1: S ramp enabled
Setting this parameter enables the S ramp function. S ramp is disabled during deceleration when the standard ramp voltage controller is active. When
the motor is accelerated again after decelerating in standard ramp the acceleration ramp used by the S ramp function is reset to zero.
The S ramp function is only available if the acceleration and deceleration rates are specified in s/100Hz (Pr 2.39 = 1).
This parameter defines the maximum rate of change of acceleration that the drive will operate with.
The default values have been chosen such that for the default ramps and maximum speed, the curved parts of the S will be 25% of the original ramp
if S ramp is enabled.
2.05 Unused parameter
2.06 S ramp enable
Coding
Bit SP FI DE Txt VM DP ND RA NC NV PT US RW BU PS
111
Default 0
Update rate Background
2.07 S ramp acceleration limit
Coding
Bit SP FI DE Txt VM DP ND RA NC NV PT US RW BU PS
1 111
Range
0.0 to 300.0s
2
/100Hz
Default 3.1
Update rate Background
DC Bus voltage
Motor Speed
Programmed
deceleration
rate
t
Controller
operational
NOTE
NOTE