VS II ...-17...45 9
7.3 Parameter settings
On the front panel there are 3 potentiometers by means of which the following settings can be
made.
Default setting of potentiometers:
Adjusting soft start
To adjust an optimum starting behavior, you should carry out a test run. Contrary to the default
settings, you should make the following basic potentiometer-settings.
Switch on the supply voltage and start acceleration. Watch the starting behavior and adapt the
approporiate parameters to your drive. At any rate, the starting voltage should be adjusted with
the potentiometer UStart so that the motor starts immediately. At the same time, unnecessary
humming with the motor being at rest is to be avoided.
The potentiometer is to be adjusted so that the requested acceleration time or starting
characteristics is achieved. The acceleration time should always be chosen as short as
possible, in order to keep the thermal stress acting on device and motor as small as possible.
This leads to short times until the bypass relays pull in and ensures good acceleration
characteristics while the power semiconductors and motor are less heated. This is of special
importance in the case of high-inertia starting or high switching frequencies. The acceleration
time, however, has to be adjusted so that the motor reaches nominal speed before the internal
bypass relays close.
Warning:
If the adjusted acceleration time is too short, the internal bypass relays close
before the motor has reached nominal speed. This can cause damage to
the bypass relays.
Parameter Poti Setting range
Acceleration time Acceleration time adjustable from 0.5...10sec
Starting voltage UStart 40…80% of rated voltage
Deceleration time adjustable from 0.5...10sec
Potentiometer (acceler. time) = mid-position
Potentiometer UStart (starting voltage) = left stop (counter-clockwise)
Potentiometer (deceler. time) = left stop (counter-clockwise)
Fans, roller tracks, conveyor belts, etc. 50%, UStart 0%, 0%
Centrifuges, conveyor screws, mixers,
compressors, etc.
50%, UStart 50%, 50%
Pressure pumps, etc. 50%, UStart 50%, 50%
