3Sk1 Output Expansions; Applications; Function Description - Siemens SIRIUS 3SK1 Equipment Manual

5.3

3SK1 output expansions

5.3.1

Applications

The 3SK1 output expansions are used to expand the safety-related outputs. The maximum
achievable Performance Level PL/Cat. in accordance with ISO 13849-1, SILCL in accordance with
IEC 62061, SIL in accordance with IEC 61508 corresponds to the Performance Level PL and SIL
of the basic unit when the external wiring (connection between basic unit and output
expansion) is configured as fail-safe (e.g. basic unit and output expansion are connected
using 3ZY12 device connector).
The output expansions can be controlled via the supply voltage (A1/A2) or using 3ZY12 device
connectors
For 24 V DC variant only
1)
Note
If expansion units are controlled via the 3ZY12 device connector, additional feeding of the
control supply voltage (A1/A2) at one of the output expansions leads to a fault in the system
configuration.
Note
Use of the output expansions on 3ZY12 device connectors
You can switch between instantaneous or delayed control of the basic unit using the slide switch
of the output expansion (see also the chapter "System configuration rules (Page 120)").
Note
Using the output expansions with conventional wiring
The slide switch has no function here.
If you require Stop category 1 outputs for the output expansion, terminals A1/A2 of the output
expansion must be connected to outputs 38 or 48 on 3SK1 basic units with relay outputs or to
Q1t/Q2t (in the case of 3SK1 with semiconductor outputs).
5.3.2

Function description

The operating state of the 3SK1 output expansions is displayed on the DEVICE LED.
The 3SK1211 output expansions (4RO) have four safety-related outputs as NO circuits, and the
3SK1213 output expansions (3RO) have three. They each have one positively-driven NC circuit.
The output expansions can be activated via any output of the basic unit via (A1). The NC circuit
51/52 of 3SK1211 (4RO) or 41/42 of 3SK1213 (3RO) is used for monitoring the output
expansions.
In the 24 V DC variants, the expansion units can be activated and evaluated via the 3ZY12 device
connectors.
SIRIUS 3SK1 Safety Relays and 3RQ1 Positively-Driven Coupling Relays
Equipment Manual, 05/2021, A5E02526190021A/RS-AE/005
.
1)
3SK1 / 3RQ1 devices
5.3 3SK1 output expansions
89