Siemens Auxiliary switch on the front, 3NO + 1NC, spring-loaded terminal Part number 3RH2911-2HA31

Product Overview

The Siemens 3RH2911-2HA31 is a front-mount auxiliary switch block designed for the SIRIUS system, with a contact configuration of 3 normally-open (NO) and 1 normally-closed (NC) contacts. It is intended for snap-on installation onto compatible contactors and relays of the SIRIUS 3RT2 and 3RH2 series, providing additional auxiliary contact functionality for monitoring and signalling tasks.

Key Features

• Auxiliary switch block with 3 NO + 1 NC contacts in one current path
• Front snap-on mounting for quick retrofit on the SIRIUS contactor/relay frames
• Spring-loaded terminal connections for reliable wiring and easy installation
• Rated for an insulation voltage of 690 V and surge withstand of 6 kV, making it suitable for robust industrial control environments

Technical Specifications

• Product Series: Siemens SIRIUS 3RH2 Auxiliary Switch Blocks
• Article Number: 3RH2911-2HA31
• Contact Configuration: 3 NO + 1 NC instantaneous contacts
• Rated Insulation Voltage (Ui): 690 V AC (pollution degree 3)
• Rated Impulse Withstand Voltage (Uimp): 6 kV
• Mechanical Service Life: Typical 10 000 000 operations
• Electrical Endurance (AC-15, 230 V): Typical 200 000 operations
• Operational Current of Auxiliary Contacts: – At AC-15/230 V: 6 A – At AC-15/400 V: 3 A – At AC-12 (24 V/230 V): 10 A
• Operating Ambient Temperature: –25 °C to +60 °C
• Storage Temperature: –55 °C to +80 °C
• Dimensions (H × W × D): 41.5 mm × 36 mm × 47.7 mm
• Net Weight (Approx.): 0.065 kg
• Connection Type: Spring-loaded terminals; solid/stranded 0.5–2.5 mm², finely stranded up to 1.5 mm²
• Protection Class Front: IP20 (with connected conductors)

Compliance & Certifications

• Designed and manufactured to Siemens SIRIUS system standards for contactor accessories
• Complies with IEC/EN standards for auxiliary contact blocks (e.g., IEC 60947-5-1)
• RoHS-compliant; document indicates environmental product declaration (EPD) available

Applications

The 3RH2911-2HA31 is ideal for use in control gear, motor-starter systems and industrial automation panels where additional auxiliary contact functionality is required for monitoring, feedback, interlocking or signalling. Its compact size, high durability and reliable contact performance enable integration with SIRIUS contactors and relays in factory automation, machinery, and process installations.