CG emotron TSA Series, Instruction Manual

Page: 152 / 204

148 Softstarter theory CG Drives & Automation 01-5980-01r2
10.4 Use of softstarters with
torque control
To determine if a specific application benefits from using a
softstarter at all, the correlation between the motor’s torque
characteristic during the start and the load’s requirements
has to be evaluated. As it can be seen from the examples
above, the application will only benefit from using a
softstarter if the load torque during the start is clearly below
the motor’s starting capacity. However, loads with a high
initial release torque may also benefit from a softstarter. In
this case an initial torque boost can be used, thereafter the
start ramp is continued reducing the starting current
considerably.
The benefit can be maximised when using a softstarter with
torque control. To be able to configure the torque control
parameters for optimal performance, the load characteristics
(linear, square or constant load, need of initial release
torque) must be known. In this case a proper torque control
method (linear or square) can be chosen and torque boost
can be enabled if needed.