Siemens SINAMICS G120 Operating Instructions Manual page 79

Special measures for wiring of a fail-safe input
The converter evaluates deviations in the two signals of the fail-safe input. The converter
thus detects, for example the following faults:
● Cable break
● Defective sensor
The converter cannot detect the following faults:
● Cross-circuit of the two cables
● Short-circuit between signal cable and 24 V power supply
You have the following options to reduce the risk of damaged cables during operation of your
machine or plant:
● Use shielded cables with grounded shield.
● Lay signal cables in steel pipes.
These special types of cable routing are normally required only if the cables are laid over
larger distances, e.g. between remote control cabinets.
Examples of connecting a fail-safe input can be found in Section: Connecting fail-safe digital
inputs (Page 336).
SINAMICS G120C frequency converter
Operating Instructions, 03/2012, FW V4.5, A5E02999804B AB
Adapting the terminal strip
7.2 Fail-safe digital input
77