Contactor Relays (Auxiliary Contactors), 3RH2 (S00) with “Mechanically linked contact elements”, DC Coil@ - 3RH2122-1BF408K

Product Description

Siemens 3RH2122-1BF408K Auxiliary Contactor Relay – 110V DC Control Relay with Mechanically Linked Contact Elements

The Siemens 3RH2122-1BF408K Auxiliary Contactor Relay is a premium industrial switching device designed for reliable control, signaling, monitoring, interlocking, and automation applications. Part of the globally recognized Siemens SIRIUS 3RH2 Series, this auxiliary contactor combines compact design, high switching performance, and advanced mechanically linked contact technology to deliver exceptional reliability in demanding industrial environments. Featuring a 110V DC coil, 2 Normally Open (2NO) contacts, 2 Normally Closed (2NC) contacts, and mechanically linked contact elements, the 3RH2122-1BF408K is an ideal choice for machine builders, OEMs, control panel manufacturers, automation engineers, and industrial maintenance professionals.

The Siemens 3RH2122-1BF408K is specifically engineered with mechanically linked contact elements, a critical safety feature in industrial automation systems. This design ensures that normally open and normally closed contacts cannot simultaneously indicate conflicting switching positions. As a result, the relay provides highly accurate feedback signals for safety circuits, interlocking systems, machine control applications, and process monitoring functions. Mechanically linked contacts are widely used in applications where operational safety and reliable status indication are essential.

The relay features a balanced 2NO + 2NC contact configuration, making it highly versatile for industrial control applications. The two normally open contacts can be utilized for PLC interfacing, control commands, signaling circuits, machine sequencing, and motor control logic. Meanwhile, the two normally closed contacts are ideal for interlocking circuits, emergency shutdown systems, fault indication, monitoring functions, and safety-related control applications. This versatile configuration allows engineers to implement complex control functions while minimizing the need for additional switching devices.

Operating on a 110V DC control supply, the 3RH2122-1BF408K Auxiliary Contactor Relay is particularly suitable for industrial systems utilizing DC control architectures. DC-operated contactors are commonly used in process industries, power plants, substations, railway applications, battery-backed control systems, and industrial automation environments where stable DC control voltages are preferred. Siemens has engineered this relay to deliver reliable operation across a broad control voltage range while maintaining consistent switching performance.

Built within the compact S00 frame size, the Siemens SIRIUS 3RH2122-1BF408K provides excellent space efficiency for modern control panels and automation cabinets. Despite its compact dimensions, the relay delivers industrial-grade switching performance capable of handling demanding control tasks. Its space-saving design enables panel builders and OEMs to maximize available cabinet space while maintaining easy access for installation, maintenance, and future system modifications.

The relay utilizes durable screw terminal connections, which continue to be the preferred wiring technology in many industrial control systems. Screw terminals provide secure conductor retention, excellent vibration resistance, and dependable long-term electrical performance. This connection technology simplifies installation while ensuring stable operation in harsh industrial environments where reliability is critical.

As a member of the Siemens SIRIUS control portfolio, the 3RH2122-1BF408K Auxiliary Contactor supports compatibility with a broad range of Siemens accessories, including auxiliary contact blocks, surge suppressors, mounting adapters, and labeling systems. This modular design philosophy simplifies engineering, reduces spare parts inventory requirements, and enables flexible customization according to specific application requirements.

The Siemens 3RH2122-1BF408K is designed to meet demanding industrial standards and performance requirements. With a rated insulation voltage of 690V, impulse withstand voltage of 6kV, and high mechanical durability, the relay provides dependable operation even under challenging electrical and environmental conditions. Its robust construction ensures long service life and minimizes downtime in critical industrial applications.

Industrial automation professionals rely on the Siemens 3RH2122-1BF408K Auxiliary Contactor Relay for applications including control panel construction, machine automation, PLC interfacing, industrial signaling, process control systems, material handling equipment, water treatment facilities, power distribution systems, and manufacturing automation. The combination of mechanically linked contacts, reliable DC coil operation, compact dimensions, and Siemens engineering excellence makes it a trusted solution across multiple industries.

The relay is particularly suitable for safety-related control systems where accurate contact feedback and dependable switching performance are required. Its mechanically linked contact design enhances operational integrity and supports the implementation of reliable interlocking and monitoring circuits.

At SBsmart.in, we supply genuine Siemens industrial automation and control products trusted by OEMs, electrical contractors, panel builders, system integrators, and industrial buyers throughout India. When you purchase the Siemens 3RH2122-1BF408K, you receive an authentic Siemens SIRIUS auxiliary contactor engineered for superior reliability, long service life, and seamless integration into modern industrial automation systems.

Whether you are designing a new automation project, upgrading an existing control panel, implementing safety interlocking circuits, or expanding machine control functionality, the Siemens 3RH2122-1BF408K Auxiliary Contactor Relay delivers the performance, durability, and quality expected from Siemens industrial control products.