Emergency Stop Shutdown To Sil 1 Sto With A 3Rw55 Failsafe Soft Starter - Siemens SIRIUS 3RW55 Equipment Manual

Note
Inside a cabinet, the cabling between the safety relay and the 3RW55 Failsafe soft starter and
between the safety relay and the redundant switching element (motor contactor) can be
installed in 1 duct. This is also permissible up to SIL 3 / PL e because the cable installation inside
the cabinet is short-circuit to power cable/short-circuit proof (fault exclusion according to EN
ISO 13849‑2).
A.4.1

EMERGENCY STOP shutdown to SIL 1 STO with a 3RW55 Failsafe soft starter

With the 3RW55 Failsafe soft starter, STO applications up to integrity level SILCL 1 according to
IEC 62061 and PL c / Cat. 2 according to EN ISO 13849 can be implemented without having to
use further devices (one-channel shutdown by the 3RW55 Failsafe soft starter). The shutdown
command at the failsafe digital input F‑DI of the 3RW55 Failsafe soft starter can come from a
directly connected EMERGENCY STOP command device or from a safe output of a higher-level
safety relay.
Note the requirements in chapter 3RW55 Failsafe soft starter (Page 343).
SIRIUS 3RW55 and 3RW55 Failsafe Soft Starters
Equipment Manual, 02/2022, A5E35630887002A/RS-AF/006
Example circuits
A.4 3RW55 Failsafe soft starter
345