Siemens 3TK2825-1BB40 Safety Relay

The Siemens 3TK2825-1BB40 safety relay provides reliable shutdown and safety circuit monitoring for industrial machines, commonly used in emergency stop circuits, safety interlocks, and guard monitoring. Operating from 24 V DC, it includes 3 normally open safety contacts plus 1 NC auxiliary contact with a switching capacity up to 5 A per contact and a fast typical response time under 30 ms. Mount it on a DIN rail with screw terminals, IP20 protection, and an operating temperature range of -25°C to +55°C, suitable for Category 3 / PL d safety applications per EN ISO 13849-1 and IEC 62061. It supports manual or automatic reset, and provides integrated monitoring for emergency stop and safety circuits. Common replacements include Siemens 3SK1111-1AB30, 3TK2827-1BB40, and 3SK1121-1AB30.