Siemens SIRIUS 3RW55 Equipment Manual page 21

Loss of the safety function due to restricted diagnostics.
Can cause death or serious injury.
For diagnostics, the 3RW55 Failsafe soft starter must always be directly connected to the main
supply voltage (operational voltage).
For diagnostics, always connect the 3RW55 Failsafe soft starter directly to the main supply
voltage (operational voltage). Additional contact elements (e.g. a redundant contactor) must
only be connected in series behind the 3RW55 Failsafe soft starter.
Loss of the safety function due to a failed thyristor.
Can cause death or serious injury.
The 3RW55 Failsafe soft starter is no longer ready for operation if it contains a failed thyristor.
Replace the 3RW55 Failsafe soft starter if a thyristor fails.
Loss of the safety function due to a short-circuit.
Can cause death or serious injury.
• Short-circuit protection for coordination type 1
• Short-circuit protection for coordination type 2
Note
Function test
In continuous operation, the key safety values apply in the case of a function test interval for
SIL 1 ≤ 1 year and for SIL 3 ≤ 1 month. The function check is part of the self-test (user-test)
(Page 264).
Note
Safe state
The basis of the safety function is the definition of the safe state. On the 3RW55 Failsafe soft
starter, the safe state is an open load circuit.
Note
Safety function
With the 3RW55 Failsafe soft starter, applications can be implemented with the safety function
"Safe Torque Off" (STO) acc. to EN 61800‑5‑2 and stop category 0 acc. to EN 60204‑1.
SIRIUS 3RW55 and 3RW55 Failsafe Soft Starters
Equipment Manual, 02/2022, A5E35630887002A/RS-AF/006
WARNING
WARNING
WARNING
The 3RW55 Failsafe soft starter is defective after a short-circuit.
Replace the defective 3RW55 Failsafe soft starter.
The 3RW55 Failsafe soft starter is still fully functional after a short-circuit.
Run the self-test (user-test) (Page 264) to check the safety function before continuing to use
the 3RW55 Failsafe soft starter.
Safety information
2.7 Failsafe
21