Siemens SIRIUS 3RK3 Equipment Manual page 142

Description of the hardware
5.3 Connecting / wiring
Connection options for the 3RK3 central units
Single-channel actuator wiring
QA/QB contactors
Q1.1, Q1.2 safety-related relay outputs
Note
* SIL 2/3 per EN 61508 or PL d/e per EN ISO 13849-1
)
To achieve SIL 2/3 per IEC 61508 or PL d/e per EN ISO 13849-1, a fault exclusion such as a short-
circuit to a power cable or ground is required. This can be implemented, for example, within a
cabinet and by installing the connection cables in such a way that they are protected.
If this is not possible, the actuators must be wired via two safety-related outputs; see the right-
hand image. For this purpose, separate cables must be laid to actuators/contactors. In the
associated function element "F output," the output type "F output redundant" must be chosen.
142
Two-channel actuator wiring via
1 safety-related output*
SIRIUS 3RK3 Modular Safety System
Equipment Manual, 07/2020, NEB926253002000/RS-AC/006
)