Siemens 3RH2140-2BB40 Contactor

Siemens 3RH2140-2BB40 is a SIRIUS auxiliary contactor relay with four normally open contacts and a 24 V DC coil, designed in the compact frame size S00 for DIN-rail mounting in control panels. It features spring-loaded terminals for secure, vibration-resistant wiring and is rated for up to 10 A load, making it suitable for lightweight motor control and signaling duties in automation circuits. The coil operates at 24 V DC and the product is equipped with an integral option to add an auxiliary contact block, enabling additional signaling contacts as needed. Electrical ratings include an insulation voltage of 690 V and a pollution degree 3, with surge withstand of 6 kV, while typical coil power loss is around 4 W. In terms of durability, the base contactor offers up to about 30 million mechanical operating cycles, with auxiliary-block configurations offering typical life in the low to mid millions (5–10 million cycles depending on configuration). This compact 4NO auxiliary contactor is often used in control cabinets for interlocking, signaling, and interface tasks, and pairs with Siemens' 3RH2 family components for expanded functionality.