Siemens Sinamics S120 Function Manual page 63

● When the "Safe Torque Off" function is selected, the following applies:
– The motor cannot be started accidentally.
– The pulse suppression safely disconnects the torque-generating energy supply to the
– The power unit and motor are not electrically isolated.
● The selection/deselection of the STO function also acknowledges the safety faults when
the Basic Functions are used. The standard acknowledgment mechanism must also be
performed.
● Extended acknowledgement:
The selection/deselection of STO can also acknowledge the safety messages of the
extended safety functions. This requires that the extended message acknowledgement is
configured (p9507.0 = 1).
If in addition to the "Extended Functions", the "Basic Functions via terminals" are also
enabled, in addition to selection/deselection of STO via PROFIsafe or TM54F,
acknowledgement is also possible by selection/deselection of STO via terminals.
● The status of the "Safe Torque Off" function is displayed using parameters (r9772, r9872,
r9773 and r9774).
Danger to life as a result of undesirable motor movement
After the energy feed has been disconnected (STO active) the motor can undesirably move
(e.g. the motor can coast down), therefore presenting risk to persons.
• Take suitable measures to prevent undesirable movement, e.g. by using a brake with
Danger to life as a result of undesirable motor movement
Undesirable motor motion can occur if 2 power transistor simultaneously become defective
(breakdown of the depletion layer). This can result in accidents leading to death or severe
injury.
• Take suitable measures to prevent undesirable movement, e.g. by using a brake with
The maximum movement can involve:
1)
● Synchronous rotary motors: Max. movement = 180° / no. of pole pairs
● Synchronous linear motors: Max. movement = pole width
Safety Integrated
Function Manual, (FHS), 07/2016, 6SL3097-4AR00-0BP6
motor.
WA RNING
safety-relevant monitoring. For additional information, see Section "Safe Brake Control
(SBC) (Page 71)".
WA RNING
safety-relevant monitoring. For additional information, see Section "Safe Brake Control
(SBC) (Page 71)".
Description of Safety Integrated functions
4.1 Safety Integrated basic functions
63