Parameterizing The Ramp-Function Generator - Siemens SINAMICS G120 Operating Instructions Manual

5.6.2

Parameterizing the ramp-function generator

Parameterizing the ramp-function generator
The ramp-function generator in the setpoint channel limits the speed of setpoint changes.
This causes the motor to accelerate and decelerate more smoothly, thereby protecting the
mechanical components of the driven machine.
Ramp-up/down time
The ramp-up and ramp-down times of the ramp-function generator can be set independently
of each other. The times that you select depend purely on the application in question and
can range from just a few 100 ms (e.g. for belt conveyor drives) to several minutes (e.g. for
centrifuges).
When the motor is switched on/off via ON/OFF1, the motor also accelerates/decelerates in
accordance with the times set in the ramp-function generator.
Table 5- 28
Parameters
P1120 = ...
P1121 = ...
The quick-stop function (OFF3) has a separate ramp-down time, which is set with P1135.
Note
If the ramp-up/down times are too short, the motor accelerates/decelerates with the
maximum possible torque and the set times will be exceeded.
CU240S and CU240E Control Units, FW 3.2
Operating Instructions, 03/2009, A5E02440075B AA
Parameters for ramp-up time and ramp-down time
Description
Ramp-up time
Duration of acceleration (in seconds) from
zero speed to the maximum frequency
(P1082).
Ramp-down time
Duration of deceleration (in seconds) from
the maximum frequency (P1082) to
standstill.
Functions
5.6 Setpoint preparation
107