Siemens 3RH2911-1HA20 Auxiliary Switch, Front-Mounted, 2 NO for 3RT2 & 3RH2 Contactors Original Brand New

Overview

The Siemens 3RH2911-1HA20 is an essential front-mounted auxiliary switch block designed to expand the control and signaling capabilities of SIRIUS 3RT2 power contactors and 3RH2 contactor relays. Featuring two (2) Normally Open (NO) instantaneous contacts with secure screw terminals, this compact and reliable switch easily snaps onto the front of compatible contactors (Sizes S00, S0, S2) for quick installation and wiring clarity.

Key Features & Specification

• Product Type: Auxiliary Switch Block
• Mounting: Front snap-on installation
• Contacts: 2 NO (Normally Open) instantaneous contacts
• Terminal Type: Screw Terminal connections
• Compatibility: Designed for use with Siemens 3RT2 Contactors and 3RH2 Contactor Relays
• Current Path: 1 NO, 1 NO (Contacts: .3/.4, .3/.4)
• Protection Class: IP20 (on the front)
• Brand Series: SIRIUS
• Operating Voltage (Rated): 690 V AC
• Mechanical Service Life: Typical 10,000,000 operating cycles

Function

The 3RH2911-1HA20 auxiliary switch is used to provide feedback (status signaling) or to enable control logic in motor control circuits. When the main contactor coil is energized, this auxiliary switch changes state (the 2 NO contacts close simultaneously), allowing its contacts to be used for:

• Signaling: Illuminating an indicator light to show the contactor is closed.
• Interlocking: Providing a signal to the control system (e.g., PLC or relay logic) confirming the contactor’s operational status.
• Self-holding Circuits: Creating a latching or “seal-in” function for the control circuit.

Benefit

• Quick & Easy Installation: Front mounting with a simple snap-on mechanism saves time during assembly and maintenance.
• Reliable Performance: Part of the trusted Siemens SIRIUS family, ensuring high mechanical and electrical endurance (10 million/200,000 cycles typical).
• Enhanced Control: Easily expands the number of available auxiliary contacts on a contactor for more complex control applications.
• Secure Connection: Screw terminals ensure a robust and reliable electrical connection, critical for industrial environments.
• Broad Compatibility: Perfectly matched for the popular 3RT2 and 3RH2 series contactors across multiple sizes (S00, S0, S2).

Application

This auxiliary switch block is ideal for a wide range of industrial control applications, including:

• Motor Control Centers (MCCs)
• Heating, Ventilation, and Air Conditioning (HVAC) systems
• Pump and Fan Control
• Conveying Systems
• Any industrial setup requiring remote status indication or control logic integration with Siemens 3RT2 contactors or 3RH2 contactor relays.

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