Connecting Pre-Processing Devices; Permissible Pre-Processing Devices; 3Tk28 Safety Relay - Siemens SINAMICS G120 Function Manual

3.2.3

Connecting pre-processing devices

3.2.3.1

Permissible pre-processing devices

If you use safety relays with electronic enabling circuits, the relays must feature outputs that
switch to P potential. The safety relay switches the 24 V supply line to the inverter but not the
ground return line.
Safety relays with relay enabling circuits are only permitted if they have an internal dual-
channel configuration.
The following pages describe a number of typical circuits for various types of safety relay.
Exactly how these are interconnected depends on whether the safety relay and the inverter
are housed in the same or separate control cabinets.
3.2.3.2

3TK28 safety relay

The typical circuits described on the following pages are based on safety relays with relay
enabling circuits. Safety relays with semiconductor enabling circuits can also be used.
The diagrams only show how the safety relay and inverter are interconnected. Information
providing full details of how the safety relay is wired can be found in the product-specific
documentation: SIRIUS 3TK28 safety relays
(http://support.automation.siemens.com/WW/view/en/26414637/133300).
Safety Integrated Function Manual, SINAMICS G120
Function Manual, 07/2010, FW 4.3.2, A5E03052391B AA
Activation
3.2 Activation via F-DI
49