Siemens SINAMICS G120 Operating Instructions Manual page 186

Functions
9.5 Setpoint preparation
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 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 9- 26
Parameter
p1120
p1121
p1135
Note
Excessively short ramp-up and ramp-down times mean that the motor reaches its current
limit when accelerating or braking. In this case, the set times are exceeded.
Extended ramp-function generator
In the extended ramp-function generator, the acceleration process can be made "softer"
using initial and final rounding via parameters p1130 ... p1134. Here, the ramp-up and ramp-
down times of the motor are increased by the rounding times.
Rounding does not affect the ramp-down time in the event of a quick stop (OFF3).
You can find more information in function diagram 3070 and in the parameter list of the List
Manual.
184
Parameters for minimum and maximum speed
Description
Ramp-function generator, ramp-up time (factory setting: 10 s)
Accelerating time in seconds from zero speed up to the maximum speed p1082
Ramp-function generator, ramp-down time (factory setting: 10 s)
braking time in seconds from the maximum speed down to standstill
OFF3 ramp-down time (factory setting: 0 s)
The quick stop (OFF3) has its own ramp-down time.
SINAMICS G120C frequency converter
Operating Instructions, 03/2012, FW V4.5, A5E02999804B AB