Residual Risk - Siemens SINAMICS S120 Function Manual

1.3

Residual risk

The fault analysis enables machine manufacturers to determine the residual risk at their
machine with regard to the drive unit. The following residual risks are known:
Danger due to short, limited movements
If two power transistors simultaneously fail in the power unit (one in the upper and one in
the lower inverter bridge), then this can cause cause brief, limited movement.
The maximum movement can be:
• Synchronous rotary motors: Max. movement = 180° / no. of pole pairs
• Synchronous linear motors: Max. movement = pole width
NOTICE
Material damage due to overshooting the speed or position that briefly violates the limit
value.
Violation of limits may briefly lead to a speed higher than the speed setpoint, or the axis
may pass the defined position to a certain extent, depending on the dynamic response of
the drive and on parameter settings.
• Design your machine appropriately.
Safety Integrated
Function Manual, 12/2018, 6SL3097-5AR00-0BP1
WARNING
Fundamental safety instructions
1.3 Residual risk
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