Safely Limited Speed, Sls; Basic Principle Of Operation; Selecting Sls When The Motor Is Switched On - Siemens SINAMICS G120 Function Manual

Description

2.6 Safely Limited Speed, SLS

2.6 Safely Limited Speed, SLS
2.6.1

Basic principle of operation

The SLS safety function continuously monitors the load speed.
SLS also limits the motor speed setpoint internally to ensure that the load speed remains
within the monitoring thresholds.
SLS does not monitor the direction of rotation.
Figure 2-5
2.6.2

Selecting SLS when the motor is switched on

The inverter monitors the load speed. To enable the inverter to calculate the load speed from
the motor speed, you have to parameterize the gear ratio and the number of motor pole
pairs.
SLS functions as follows:
● The operator selects the SLS safety function via a fail-safe input or via PROFIsafe (safe
24
Basic principle of operation of SLS
bus communication).
– If the motor torque has already been cut off when SLS is selected, you must switch on
the motor within 5 seconds. Further information can be found in the section Switching
on the motor when SLS is active (Page 27).
– If the motor has already been switched on when SLS is selected, the motor behaves
differently depending on the load speed. These two scenarios are described below.
Safety Integrated Function Manual, SINAMICS G120
Function Manual, 07/2010, FW 4.3.2, A5E03052391B AA