Siemens 3TK2821-1CB30 Industrial Control Relay

Siemens 3TK2821-1CB30 is a SIRIUS safety relay with relay enabling circuits (EC) designed for machine safety applications such as emergency stops and protective doors. It operates from a 24 V AC/DC coil and provides three normally open contacts plus one normally closed signaling contact (MK), all packaged in a 22.5 mm-wide unit intended for DIN-rail mounting with screw-terminal connections. The safety relay is UL-listed (UL E44653) and can be used in IP20 configurations or IP40 when enclosed, with SIL3 capability for formal safety circuits; RC input logic offers instantaneous (3 s) and delayed (0 s) operating modes for enabling signals, and autostart is supported.