Contactor Relays (with Low power consumption coil), Auxiliary Contactor - Coupling Relays, Screw terminals - 3RH2140-1KB40

Product Description

Siemens 3RH2140-1KB40 Coupling Contactor Relay – Low Power Consumption Auxiliary Relay for PLC and Automation Applications

The Siemens 3RH2140-1KB40 Coupling Contactor Relay is a specialized industrial control component designed for reliable switching of auxiliary circuits in modern automation systems. Part of the globally trusted Siemens SIRIUS 3RH2 Series, this coupling relay is specifically engineered for use with PLC outputs, electronic control systems, and low-power automation applications. Featuring 4 Normally Open (4NO) contacts, a 24V DC low-power consumption coil, integrated suppressor diode protection, and robust screw terminal connections, the 3RH2140-1KB40 delivers exceptional reliability, energy efficiency, and long-term performance in industrial environments.

Unlike standard contactor relays, the Siemens 3RH2140-1KB40 is classified as a coupling contactor relay, specifically developed to interface electronic control devices with industrial switching circuits. Siemens designed this series to meet the special requirements of PLC-controlled applications where low power consumption, reliable operation, and compatibility with solid-state outputs are critical. The relay is suitable for switching auxiliary circuits while maintaining high contact reliability even at low voltages and currents.

One of the most important advantages of the 3RH2140-1KB40 is its low power consumption coil technology. Operating at only 2.8W with a 24V DC control supply, this relay significantly reduces the load on PLC outputs and electronic control circuits compared to conventional contactors. This makes it particularly suitable for automation systems where energy efficiency and direct PLC compatibility are important considerations.

The Siemens 3RH2140-1KB40 Coupling Relay features a 4NO contact configuration, providing four instantaneous normally open contacts for flexible switching applications. This contact arrangement is ideal for PLC signal expansion, control logic implementation, interlocking circuits, signaling systems, automation commands, machine control functions, and industrial process control applications. The four-contact configuration allows engineers to perform multiple switching operations from a single compact device, reducing panel complexity and installation costs.

A key feature of the 3RH2140-1KB40 is its integrated suppressor diode, which provides built-in protection against voltage spikes generated during coil switching operations. The suppressor diode helps protect sensitive PLC outputs, electronic control devices, and semiconductor switching components from damaging overvoltage conditions. This integrated protection improves system reliability and reduces the need for additional external suppression components.

The relay utilizes durable screw terminal connections, ensuring secure conductor retention and long-term electrical reliability. Screw terminals remain a preferred choice in industrial control systems due to their vibration resistance, maintenance-friendly design, and dependable electrical performance. This connection method makes installation simple while ensuring stable operation even in demanding industrial environments.

Designed in the compact S00 frame size, the Siemens 3RH2140-1KB40 offers excellent space efficiency for control panels, automation cabinets, and switchboards. Despite its compact dimensions, the relay provides robust switching performance and supports a wide operating range of 0.7 to 1.25 times the rated control voltage, ensuring reliable operation even under fluctuating supply conditions. This extended operating range is a major advantage of Siemens coupling relays and helps improve system stability.

The Siemens SIRIUS 3RH2140-1KB40 is particularly suitable for direct connection to PLC outputs. Siemens specifically developed the coupling relay range for electronic control systems where standard contactors may consume excessive coil current. The relay provides high contact reliability for solid-state circuits and can switch auxiliary loads while maintaining low control circuit power requirements.

The device complies with internationally recognized standards including IEC 60947-1, IEC 60947-4-1, and IEC 60947-5-1, ensuring reliable operation and compatibility with global industrial automation requirements. It supports a rated insulation voltage of 690V, impulse withstand voltage of 6kV, and offers industrial-grade durability for continuous operation in demanding environments.

The Siemens 3RH2140-1KB40 Coupling Relay is widely used in PLC control panels, machine automation systems, process control installations, material handling equipment, packaging machinery, HVAC controls, water treatment facilities, energy management systems, and industrial automation projects. Its combination of low power consumption, PLC compatibility, integrated protection, and Siemens reliability makes it a preferred solution for modern control systems.

At SBsmart.in, we supply genuine Siemens industrial automation and control products trusted by OEMs, panel builders, electrical contractors, automation engineers, and industrial buyers across India. When you choose the Siemens 3RH2140-1KB40, you receive an authentic Siemens SIRIUS coupling relay engineered for superior performance, energy efficiency, and long-term operational reliability.