Safe Standstill (Sh) - Siemens SINAMICS S120 Installation And Start-Up Manual

SINAMICS Safety Integrated (Booksize)

Safe standstill (SH)

5.2 Safe standstill (SH)
General description
In conjunction with a machine function or in the event of an error, the "Safe stand-
still (SH)" function is used to safely disconnect the torque-generating motor power
supply.
When the function is selected, the drive unit is in a "safe status". The power-on
disable function prevents the drive unit from being restarted.
The pulse disable integrated in the Motor Modules is a prerequisite for this func-
tion.
Features of "safe standstill"
S This function is drive autonomous, that is, no higher-level controller is required.
S The function is drive specific, that is, it must be commissioned individually on a
drive-by-drive basis.
S The function must be enabled via the appropriate parameters.
S The terminals for the "safe standstill" function can be grouped together.
S When the "safe standstill" function is selected:
– The motor cannot be started accidentally.
– The pulse disable safely disconnects the torque-generating motor power
supply.
– The Motor Module and motor are not electrically isolated.
Caution
!
Appropriate measures must be taken to ensure that the motor does not move
once the motor power supply has been disconnected ("coast down") (e.g. enable
the "Safe brake control" function with a vertical axis).
Caution
!
If two power transistors in the Motor Module (one in the upper and one in the lower
bridge) fail at the same time, this can cause a momentary movement.
The maximum movement can be:
Synchronous rotary motors: max. movement = 180_ / no. of pole pairs
Synchronous linear motors: max. movement = pole width
S The status of the "Safe standstill" function is displayed via the appropriate
parameters.
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E Siemens AG, 2004. All rights reserved
SINAMICS S120 Installation and Start-Up Manual, 12/04 Edition