Product Description

Siemens 3RH2911-1FA40 Auxiliary Contact Block – 4 NO, Front Mounting

The Siemens 3RH2911-1FA40 is a front-mountable auxiliary contact block from the Siemens SIRIUS accessory range, designed for compatible 3RT2 contactors and 3RH2 contactor relays. It provides 4 normally open (4 NO) instantaneous auxiliary contacts with screw-terminal connections. Siemens currently lists this article as an active product.

The accessory is designed to add additional control, signalling, feedback and interlocking capabilities to a compatible contactor without changing its main power-switching function.

Siemens SIRIUS Auxiliary Contact Block

The 3RH2911-1FA40 provides four additional auxiliary switching paths for industrial control and automation circuits.

These auxiliary contacts can be used for:

• Contactor status feedback

• PLC input signals

• Auxiliary signalling

• Machine sequencing

• Electrical interlocking

• Control-circuit logic

• Motor-control circuits

• Industrial automation

Siemens specifies this auxiliary switch for compatible 3RT2.1, 3RT2.2, 3RT2.3, 3RT2.4 and 3RH2 devices.

4 NO Instantaneous Auxiliary Contacts

The 3RH2911-1FA40 provides 4 normally open auxiliary contacts, all operating instantaneously.

The four contact paths are identified as:

• .3/.4

• .3/.4

• .3/.4

• .3/.4

This configuration provides multiple additional NO switching paths for control, feedback and signalling circuits.

Typical uses include:

• Contactor ON feedback

• PLC monitoring

• Auxiliary relay logic

• Machine sequencing

• Status indication

• Control-system feedback

• Auxiliary signalling

• Interlocking circuits

The connected electrical circuits should always remain within the applicable contact ratings.

Front-Snap Mounting

The 3RH2911-1FA40 is designed for snapping onto the front of compatible Siemens SIRIUS contactors and contactor relays.

This allows four additional auxiliary contacts to be added directly to the front of the compatible device while maintaining a compact control-panel arrangement. Siemens identifies the article specifically as a front auxiliary switch for the compatible SIRIUS devices.

The front-mount design is useful for:

• Motor starters

• Machine-control panels

• Automation cabinets

• OEM control systems

• Industrial electrical assemblies

Screw-Terminal Connections

The 3RH2911-1FA40 uses screw terminals for its auxiliary-contact connections. This provides a familiar wiring method for electrical panel builders and maintenance teams.

Screw-terminal wiring can support straightforward installation, commissioning and maintenance of control and signalling circuits.

Instantaneous Auxiliary Switching

All four contacts in this configuration are instantaneous NO contacts. There are no NC or changeover contacts in the standard configuration. Siemens product data specifies 4 instantaneous NO contacts and 0 NC contacts.

This makes the block suitable when multiple auxiliary outputs need to follow the operating state of the connected contactor or contactor relay without an intentional timing delay.

Compatibility with 3RT2 and 3RH2 Devices

The 3RH2911-1FA40 is designed for compatible Siemens SIRIUS devices, including:

• 3RT2.1 contactors

• 3RT2.2 contactors

• 3RT2.3 contactors

• 3RT2.4 contactors

• 3RH2 contactor relays

The exact compatibility should be verified against the complete contactor or contactor-relay article number before installation.

Industrial Automation Applications

The 3RH2911-1FA40 can expand the auxiliary functionality of compatible SIRIUS contactors and contactor relays.

Motor Control

The four NO contacts can provide contactor-state feedback and additional control paths in motor starters.

PLC Systems

Multiple auxiliary contacts can be connected to PLC digital inputs for monitoring, sequencing and signalling.

Machine Control

The additional NO contacts can support machine logic, status indication and sequence control.

Industrial Control Panels

The front-snap mounting arrangement provides a compact method of adding several auxiliary switching paths directly to a compatible device.

Automation Systems

The four separate NO contact paths can provide multiple feedback and control signals within automated equipment.

Suitable for OEMs and Panel Builders

The 3RH2911-1FA40 is suitable for OEM machine manufacturers, electrical panel builders, automation integrators and industrial maintenance professionals.

Its 4 NO contact configuration, front-snap mounting and screw-terminal connections make it a practical accessory for applications requiring multiple auxiliary signalling or control paths.

Key Features

• Siemens SIRIUS auxiliary contact block

• Article number 3RH2911-1FA40

• Front-snap mounting

• 4 NO auxiliary contacts

• All contacts instantaneous

• Screw terminals

• Compatible with selected 3RT2 contactors

• Compatible with 3RH2 contactor relays

• Suitable for PLC feedback

• Suitable for machine sequencing

• Suitable for signalling and control

• Suitable for industrial automation

Benefits

• 4 NO contacts: Provides four additional normally open switching paths.

• Front mounting: Allows direct installation onto compatible Siemens SIRIUS devices.

• Instantaneous operation: Auxiliary contacts follow the operating state of the associated device.

• Screw terminals: Provides a familiar industrial wiring method.

• Multiple feedback paths: Useful for PLC monitoring and machine-control logic.

• Compact design: Helps maintain an organized control-panel layout.

• Easy expansion: Adds multiple auxiliary functions without replacing the main contactor.

• Industrial suitability: Designed for Siemens SIRIUS contactor and contactor-relay systems.

Why Choose Siemens 3RH2911-1FA40?

The Siemens 3RH2911-1FA40 provides a convenient way to add four instantaneous normally open auxiliary contacts to compatible Siemens SIRIUS contactors and contactor relays.

Its 4 NO configuration, front-snap mounting and screw-terminal connections make it suitable for applications requiring multiple contactor feedback, signalling, machine sequencing or control functions. Siemens currently identifies the article as an active product.

For OEMs, panel builders and automation integrators, it provides a compact solution for expanding auxiliary control functionality while keeping the main power-switching arrangement unchanged.

Delivery Across India

SB Smart supplies Siemens industrial electrical and automation products across Faridabad, Gurgaon/Gurugram, Delhi NCR, Haryana, Noida, Punjab, Mumbai and all major cities across India.

Major delivery locations include:

• Faridabad

• Gurgaon/Gurugram

• Delhi

• Delhi NCR

• Noida

• Greater Noida

• Haryana

• Punjab

• Mumbai

• Pune

• Ahmedabad

• Bengaluru

• Hyderabad

• Chennai

• Kolkata

• Jaipur

• Chandigarh

• Lucknow

• Indore

• Surat

• Vadodara

• Nagpur

• Coimbatore

• And other major cities across India

Frequently Asked Questions

1. What is Siemens 3RH2911-1FA40?

It is a Siemens SIRIUS front-mountable auxiliary contact block with 4 normally open instantaneous contacts.

2. How many auxiliary contacts does it provide?

It provides 4 NO auxiliary contacts.

3. Are the contacts instantaneous?

Yes. All four contacts are instantaneous NO contacts.

4. How is it mounted?

It is designed for snap-on front mounting on compatible Siemens SIRIUS devices.

5. What type of terminals does it use?

It uses screw terminals.

6. Which Siemens devices are compatible?

It is specified for compatible 3RT2.1, 3RT2.2, 3RT2.3, 3RT2.4 and 3RH2 devices.

7. What can the four NO contacts be used for?

They can be used for PLC feedback, signalling, machine sequencing, control logic and auxiliary switching.

8. Does it switch the main electrical load?

No. It provides auxiliary contacts for control and signalling; the main load remains switched by the compatible contactor.

9. Is it suitable for OEM machinery?

Yes. It is suitable for OEM machine builders, panel manufacturers, automation integrators and industrial maintenance applications.

10. Where can I buy Siemens 3RH2911-1FA40 in India?

You can explore the Siemens product range at SB Smart for Siemens auxiliary contact blocks, contactors, contactor relays and other industrial automation products.