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).
Example circuits
A.4 3RW55 Failsafe soft starter
SIRIUS 3RW55 and 3RW55 Failsafe Soft Starters
Equipment Manual, 02/2022, A5E35630887002A/RS-AF/006
345