Siemens SINUMERIK 840D sl Function Manual page 135

03.06
Caution
!
During "normal" operation, speed overshoot should not unintentionally initiate the
SBR. Speed overshoot should therefore be checked by making the appropriate
measurements.
Warning
!
If the "safe standstill" function or "STOP A" is activated, the motor can no longer
generate any torque. This is the reason that potentially hazardous motion can
occur, e.g. for the following:
S When an external force acts on the drive axes
S Vertical and inclined axes without weight equalization
S Axes that are moving (coasting down)
S Direct drives with low friction and low self-locking
S Notching torques (depending on the motor type, bearing design and friction
characteristics, up to half a pole pitch in a direction that cannot be predicted)
Possible hazards must be clearly identified using a risk analysis that must be
carried-out by the manufacturer. With an assessment, based on this risk analysis,
it should be defined as to which additional measures are required, e.g. external
brakes.
© Siemens AG, 2006. All rights reserved
SINUMERIK 840D sl/SINAMICS S120 SINUMERIK Safety Integrated (FBSI sl) – 03.2006 Edition
Safety Functions Integrated in the System/Drive
6.4 Safe braking ramp (SBR)
6-135