Safety Input - Siemens SINAMICS G120 Operating Instructions Manual

Installing
4.6 Installing Control Unit
4.6.4.3

Safety input

Which devices are you allowed to connect?
The safety-related input is designed for the following devices:
● Connection of safety sensors, e.g. emergency stop command devices or light curtains.
● Connection of pre-processing devices, e.g. fail-safe control systems and safety relays.
Signal state
The inverter expects signals with the same state at its safety-related input:
● High signal: The safety function is deselected.
● Low signal: The safety function is selected.
Connect P/P and P/M-switching safe outputs
PP-switching output
Fault detection
The inverter evaluates deviations in the two signals of the safety-related input. The inverter
thus detects, for example the following faults:
● Cable break
● Defective sensor
The inverter cannot detect the following faults:
● Cross-circuit of the two cables
● Short-circuit between signal cable and 24 V power supply
Special measures to prevent cross-circuits and short-circuits
The routing of cables over longer distances, e.g. between remote control cabinets, increases
the risk of damaging cables. Damaged cables raise the risk of an undetected cross-circuit
with power-conducting cables laid in parallel. A cross-circuit can cause interruption to the
transfer of safety-related signals.
To reduce the risk of cable damage, you need to lay signal lines in steel pipes.
Bright and dark test
The inverter filters signal changes using bright and dark tests at its safe input using an
adjustable software filter.
114
PM-switching output
Connecting the safety-related input (Page 499)
It is permissible to connect PP and PM-
switching safe outputs to a safe input.
Converter with the CU240B-2 and CU240E-2 Control Units
Operating Instructions, 01/2016, FW V4.7 SP6, A5E34259001B AC