Siemens SIRIUS 3SK1 Manual page 111

Configuration notes for using device connectors
3ZY12 device connectors can only be used with devices of the Advanced device series.
Further configuration notes:
NOTICE
Only one 3SK1 Advanced basic unit is permitted in each system
The safety function is not guaranteed when more than one basic unit is used.
Supply voltage must only be fed in on the basic unit
The supply voltage of 24 V DC must only be fed in on the basic unit, otherwise the safety
function is bypassed.
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.
Power supply by means of the 3SK1230 power supply
● When device connectors are used, only one 3SK1230 power supply is permitted in each
system.
● The 3SK1230 power supply must always be located on the extreme left.
● If a 3SK1230 power supply is used, an additional (external) 24 V DC connection is not
permitted (this also applies to the cascading input, as well as to non-floating sensors).
24 V DC supply voltage from an external power supply unit
● It is only permitted to connect a voltage of 24 V DC to the terminals on the basic unit.
● It is not permitted to supply 24 V DC to an expansion component or 3RM1 Failsafe motor
starter.
SIRIUS 3SK1 safety relays
Manual, 06/2018, A5E02526190021A/RS-AD/004
WARNING
System configuration
6.3 System configuration rules
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