Siemens SINAMICS S120 Function Manual page 95

Extended Functions
Extended Functions SS1, SLS, SDI, and SSM "without encoder" do not require safety-
related speed actual value sensing. If an encoder is used for the drive control, this has no
influence on the sensorless safety functions. You can use Extended Functions "without
encoder" with the following motor types:
● Induction motor in all control modes
● SIMOTICS A-1FU synchronous motors (previously: SIEMOSYN) with U/f control
● Synchronous-reluctance motors in vector control
The Safety Integrated Functions "without encoder" are also permitted for group drives
(multiple motors connected to one power unit).
Note
The slip of an induction motor must be taken into account
For Safety Integrated without encoder (depending on the drive load), as a result of slip for
induction motors (deviations between electrical and mechanical speed), deviations can occur
between the safely determined electrical speed and the mechanical speed at the motor
shaft.
When using Extended Functions, observe the following restrictions:
Synchronous reluctance motors with Safety Integrated Functions "without encoder"
SINAMICS S120 supports synchronous reluctance motors with Safety Integrated Functions
"without encoder". Note the following information for this application case:
● Synchronous reluctance motors may only be operated with vector control.
● From the perspective of Safety Integrated, synchronous reluctance motors fall into the
"asynchronous motor" category.
● Safety Integrated supported synchronous reluctance motors in the 0.55 to 98 kW range.
Support of devices in "Chassis" format is intended for later firmware versions.
● Technical details:
– Synchronous reluctance motors have no slip: The note "Slip of an induction motor
– If you activate the function "Closed-loop controlled operation down to f = 0 Hz with test
– Compared to induction motors, synchronous reluctance motors require a shorter time
Safety Integrated
Function Manual, 12/2018, 6SL3097-5AR00-0BP1
must be taken into account" mentioned above does not apply to synchronous
reluctance motors.
signal" (p1750.5 = 1), synchronous reluctance motors do not require current injection.
for magnetization: This reduces the wait time when starting with active encoderless
safety monitoring, e.g. for SLS.
Description of Safety Integrated functions
4.2 Safety Integrated Extended Functions
93