Product Description

Siemens 3RH2911-1HA20 Auxiliary Contact Block – 2 NO

The Siemens 3RH2911-1HA20 is a front-mountable auxiliary contact block from the Siemens SIRIUS accessory range, designed for compatible 3RT2 contactors and 3RH2 contactor relays. It provides 2 normally open (2 NO) instantaneous auxiliary contacts with screw-terminal connections. Siemens product data identifies it specifically as a front auxiliary switch for these compatible devices.

The accessory adds extra control and signalling contacts to a compatible contactor without changing the main power-switching function.

Siemens SIRIUS Auxiliary Contact Block

The 3RH2911-1HA20 is designed to expand the auxiliary-contact functionality of compatible Siemens SIRIUS devices.

Auxiliary contacts can be used for:

• Contactor status feedback

• PLC input signals

• Electrical interlocking

• Control-circuit logic

• Machine sequencing

• Auxiliary signalling

• Motor-control circuits

• Industrial automation

Siemens identifies this model for compatible 3RT2 contactors and 3RH2 contactor relays.

2 NO Auxiliary Contacts

The 3RH2911-1HA20 provides 2 normally open auxiliary contacts.

The two NO contact paths are identified as .3/.4 and .3/.4 in the Siemens product data.

These contacts can be used for:

• Contactor ON feedback

• PLC monitoring

• Auxiliary relay logic

• Electrical interlocking

• Machine sequencing

• Status indication

• Control-system feedback

Because both contacts are normally open, they provide additional switching paths that close when the associated contactor operates.

Front-Snap Mounting

The 3RH2911-1HA20 is designed for snapping onto the front of compatible SIRIUS contactors and contactor relays.

Siemens lists this device as a front-mounted auxiliary switch for sizes S00 to S3, making it suitable for compatible contactor and contactor-relay configurations.

This arrangement is useful for:

• Motor starters

• Machine-control panels

• Compact automation cabinets

• OEM control systems

• Industrial electrical assemblies

Screw-Terminal Connections

The auxiliary contact block uses screw terminals, providing a conventional and familiar wiring method for industrial control-panel applications.

This supports practical installation, commissioning and maintenance of auxiliary control circuits.

Instantaneous Auxiliary Contacts

The 3RH2911-1HA20 has 2 instantaneous NO contacts. The auxiliary contacts operate with the associated contactor rather than providing a separate time-delay function.

This makes the block suitable for immediate feedback, signalling and interlocking applications.

Compatibility with Siemens SIRIUS Devices

The accessory is intended for compatible Siemens SIRIUS devices, including suitable:

• 3RT2 contactors

• 3RH2 contactor relays

• S00/S0/S2/S3-size compatible assemblies

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

Industrial Automation Applications

The 3RH2911-1HA20 can expand the control and monitoring functionality of a compatible contactor or contactor relay.

Motor Control

The two NO contacts can be used for contactor-status feedback and additional control logic in motor starters.

PLC Systems

The auxiliary contacts can provide digital feedback to PLC inputs for monitoring contactor operation.

Machine Control

They can be used for sequencing, status signalling and control logic.

Industrial Control Panels

The front-snap design provides a compact method of adding auxiliary switching capability directly to a compatible contactor.

Automation Systems

The additional contacts can provide separate control and feedback paths within automated machinery.

Suitable for OEMs and Panel Builders

The 3RH2911-1HA20 is suitable for OEM machine manufacturers, electrical panel builders, automation integrators and industrial maintenance professionals.

Its 2 NO configuration, front-snap mounting and screw-terminal connections make it a practical accessory for expanding compatible Siemens SIRIUS contactor assemblies.

Key Features

• Siemens SIRIUS auxiliary contact block

• Article number 3RH2911-1HA20

• Front-mountable design

• Snap-on mounting

• 2 NO auxiliary contacts

• Instantaneous contacts

• Screw terminals

• Compatible with selected 3RT2 contactors

• Compatible with 3RH2 contactor relays

• Suitable for PLC feedback

• Suitable for electrical interlocking

• Suitable for machine-control applications

• Suitable for industrial automation

Benefits

• 2 NO contacts: Provides two additional normally open switching paths.

• Front mounting: Allows convenient installation directly onto compatible devices.

• Screw terminals: Provides a familiar industrial wiring method.

• PLC integration: Supports contactor-status monitoring.

• Control flexibility: Provides additional contacts for signalling and machine logic.

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

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

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

Why Choose Siemens 3RH2911-1HA20?

The Siemens 3RH2911-1HA20 provides a simple and effective way to add two normally open auxiliary contacts to compatible Siemens SIRIUS contactors and contactor relays.

Its front-snap mounting, instantaneous 2 NO contact arrangement and screw terminals make it suitable for applications requiring additional contactor feedback, signalling, interlocking or control functions. Siemens product information confirms the 2 NO configuration and compatibility with 3RT2/3RH2 devices.

For OEMs, panel builders and automation integrators, it provides a compact solution for expanding auxiliary control functionality.

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 3RH2911-1HA20?

It is a Siemens SIRIUS front-mountable auxiliary contact block with 2 normally open contacts.

2. How many auxiliary contacts does it provide?

It provides 2 NO auxiliary contacts.

3. Are the contacts instantaneous?

Yes. Both auxiliary 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 designed for compatible 3RT2 contactors and 3RH2 contactor relays, including the relevant S00/S0/S2/S3 device sizes.

7. What can the NO contacts be used for?

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

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 3RH2911-1HA20 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.