Siemens SIRIUS Auxiliary Contact Block 1NO+3NC, Front Mounting, Screw Terminals, 3RH2911-2HA13

Industrial electricians and panel builders use the Siemens SIRIUS auxiliary contact block to expand the signaling and interlocking capabilities of contactors and contactor relays. The 3RH2911-2HA13 block clips onto the front of a 3RT2 contactor or 3RH2 contactor relay without tools, adding one normally open and three normally closed contacts. This configuration suits control circuits that need a mix of status feedback and safety interlocks, such as motor starters, conveyor systems, and machine tools.

Key specifications

• Contact configuration: 1 NO + 3 NC
• Mounting type: front mounting
• Rated insulation voltage (Ui): 690 V
• Rated impulse withstand voltage (Uimp): 6 kV
• Rated operating current (AC-15, 230 V): 6 A
• Rated operating current (DC-13, 24 V): 10 A
• Degree of protection: IP20 (terminals), IP40 (front)
• Ambient operating temperature: -25 to +60 °C
• Terminal type: screw terminals
• Conductor cross-section (solid): 0.5 - 4 mm²
• Conductor cross-section (fine-strand with end sleeve): 0.5 - 2.5 mm²
• Mechanical endurance: 30 million switching cycles
• Electrical endurance: 10 million switching cycles
• Number of poles: 4-pole
• Product series: SIRIUS
• Standards: IEC 60947-5-1, EN 60947-5-1

Why choose it

The block is part of the SIRIUS modular system, so it integrates mechanically and electrically with existing Siemens switching devices. Front mounting saves wiring time during installation and maintenance, and the screw terminals accept a wide range of conductor sizes for flexible panel wiring. The high mechanical endurance reduces replacement frequency in high-cycle applications.

Ideal use cases

• Adding auxiliary contacts to contactors in motor control circuits
• Providing status feedback to PLC inputs
• Implementing electrical interlocks for safety circuits
• Expanding contactor relays in automation panels

Good to know

The 3RH2911-2HA13 is a 4-pole auxiliary contact block. It is designed for use with SIRIUS 3RT2 contactors and 3RH2 contactor relays. The front mounting mechanism ensures a secure fit without additional accessories.