Siemens SINAMICS S120 Function Manual page 97

● Current limiting of the power unit
When the current limiting of the power unit responds, then it can be assumed that this will
result in errors in the encoderless safe actual value sensing and in turn with an
associated stop response.
Note
When engineering the drive and when the parameterizing the current and torque limits, it
must be ensured that the power unit current limiting does not respond.
● Operation with pulling loads
It is not permissible that the converter is forced into regenerative operation as a result of
external forces.
Note
If a coupled drive comprises an electric drive that motors and one that regenerates (e.g. a
test stand), and the speeds of both drives are safely monitored, safety functions without
encoder can be used. This is because in the case of a fault, the motoring drive
recognizes when a limit value is violated. If, in this example, the motoring drive is an
internal combustion engine, which is not safely monitored, use of safety functions without
an encoder for the braking drive is not permissible.
Winders with a motoring and a braking drive can be assessed in the same way (both
drives are monitored).
● Motor data identification
When using the measuring functions (stationary and rotating measurement) to determine
the motor data, then it can be assumed that the encoderless safe actual value sensing
will have an error.
Note
The motor data identification should always be performed before commissioning the
Safety Integrated Functions.
● Data set switchover
The motor and drive data switchover can always be used for safety functions without
encoder. It is not possible to switch over between induction and synchronous motors (this
is interlocked). For several motor data sets it must be ensured that all motors have the
same number of pole pairs. If the number of pole pairs in r0313 is not the same value that
was taken into account when configuring the safe actual value sensing (gearbox), then
the calculated, safe actual speed no longer corresponds to the mechanical speed of the
shaft.
When SLS is activated, the shaft can rotate faster than the configured limits.
● Alternating acceleration/deceleration
For alternating acceleration and deceleration, it must be ensured that the following
conditions are maintained.
– Within 1 s, only one acceleration and one braking ramp are permitted.
Safety Integrated
Function Manual, 12/2018, 6SL3097-5AR00-0BP1
Therefore, for a cycle 0 → +n
Description of Safety Integrated functions
4.2 Safety Integrated Extended Functions
→ -n → 0 – one period of at least 2 s is required.
set set
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