3TK2805-0AC02 - Safety block - SIEMENS

SIRIUS 3TK28 safety logic blocks are mainly used in stand-alone safety applications, not connected to a safety bus system. They provide sensor analysis and safety cut-off in the event of danger. In addition, they control and monitor the sensors, actuators and safety functions of the safety logic block.

Depending on the external circuit of the device, it is possible to realize, with sensors and actuators, applications up to category 4 according to EN 954-1 or SILCL 3 according to IEC 62061 / PLe according to EN ISO 13849-1. In these applications, 3TK28 safety logic blocks provide the following functions:

● monitoring sensor safety functions

● monitoring of sensor cables

● monitoring the proper functioning of the safety logic block

● monitoring of actuator shutdown

● safety cut-off of dangers

Device properties

● PLe according to EN ISO 13849-1; SIL 3 according to IEC 61508 / IEC 62061

● Wire break detection in the measuring circuit

● positively operated safety output contacts: 3 NO contacts, 1 NC contact for AC 250 V

● 2 solid-state signaling outputs

● 1 two-way signaling contact

● Adjustable voltage threshold Uan

● Adjustable stopping time ts

● LED indicators for motor stop, wire break and operating voltage

● suitable for use in conjunction with frequency converters

A frequency converter generates an offset (DC share) when braking. This can be identified and recorded by the stop detector as a wire break. The same thing also happens for direct current braking. The validation circuit is only released:

● when braking is finished, that is to say when the stop detector no longer identifies a CC part (-> the motor is stopped) and the control terminals X2 - X3 are shunted.

● or that a manual Reset is carried out from these terminals. If using the 3TK2810 with a frequency converter, it would be advisable to shunt terminals X2 - X3 or carry out a manual reset before restarting.