Siemens 3TK2806-0BB4 Time Delay Relay Module 24VDC

Siemens 3TK2806-0BB4 is a safety contactor/relay combination designed for safety circuits in machine control. It features a 24 V DC coil and a 5 NO plus 1 NC contact arrangement, with a self-latching mechanism (K1) to maintain the safe state after actuation. This DC-operated device is intended for enabling and signaling in safety circuits, providing a robust interface between control logic and main safety contacts. When wired as a safety relay, the 3TK2806-0BB4 supports interlocking and start/stop signaling required for dependable machine protection; its five normally open contacts allow controlled load switching while the one normally closed contact can be used for auxiliary signaling. The product was listed by Siemens with article number 3TK28060BB4 and is described in Siemens' catalog as a 24 V DC safety relay/contactor combination. Note that Siemens Industry Mall lists this model as discontinued without a direct replacement, so users designing new panels may need to evaluate current equivalents. Typical uses include safety interlocks and control logic where a latched safety state is required, ensuring that a fault condition leaves the machine in a safe state until a reset. With its compact form factor and DC coil, the 3TK2806-0BB4 integrates into standard control cabinets alongside contactors and circuit breakers, providing a consolidated safety solution from Siemens.