Product Description

Siemens 3RH2911-1HA11 Auxiliary Contact Block – 1 NO + 1 NC

The Siemens 3RH2911-1HA11 is a front-mountable auxiliary contact block from the Siemens SIRIUS accessory range, designed for compatible 3RT2 contactors and 3RH2 contactor relays. It provides 1 normally open (NO) and 1 normally closed (NC) instantaneous auxiliary contact with screw-terminal connections. Siemens currently lists the article as an active product.

The accessory is used to expand the control, signalling, feedback and interlocking functionality of compatible contactors without changing their main power-switching function.

Siemens SIRIUS Auxiliary Contact Block

The 3RH2911-1HA11 provides additional auxiliary switching paths for industrial control and automation circuits.

These 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 specifies this auxiliary switch for compatible 3RT2.1, 3RT2.2, 3RT2.3, 3RT2.4 contactors and 3RH2 contactor relays.

1 NO + 1 NC Auxiliary Contacts

The 3RH2911-1HA11 provides two instantaneous auxiliary contacts:

1 NO + 1 NC

The contact paths are .1/.2 for the NC contact and .3/.4 for the NO contact.

This combination gives flexibility for control and monitoring circuits.

Typical uses include:

• Contactor ON feedback

• PLC monitoring

• Electrical interlocking

• Auxiliary signalling

• Machine sequencing

• Status indication

• Control-system logic

• Relay circuits

Front-Snap Mounting

The 3RH2911-1HA11 is designed to snap onto the front of compatible Siemens SIRIUS contactors and contactor relays.

Its front-mounted design allows additional auxiliary contacts to be added directly to the device while maintaining a compact control-panel layout. Siemens identifies the product specifically as an auxiliary switch for snapping onto the front.

It is suitable for:

• Motor starters

• Machine-control panels

• Automation cabinets

• OEM control systems

• Industrial electrical assemblies

Screw-Terminal Connections

The 3RH2911-1HA11 uses screw terminals for its auxiliary connections.

This provides a conventional and familiar wiring method for electrical panel builders and maintenance teams.

The screw-terminal arrangement supports practical installation and servicing when wiring is carried out according to the manufacturer's requirements.

Instantaneous Auxiliary Contacts

Both auxiliary contacts in this configuration are instantaneous:

• 1 instantaneous NC

• 1 instantaneous NO

There is no delayed switching function in this auxiliary block.

This makes it suitable when auxiliary contacts 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 3RH2911-1HA11 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 checked against the complete contactor or contactor-relay article number before installation.

Industrial Automation Applications

The auxiliary contact block can expand the control functionality of compatible SIRIUS devices.

Motor Control

The NO and NC contacts can be used for contactor-state feedback and interlocking in motor starters.

PLC Systems

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

Machine Control

The 1 NO + 1 NC arrangement can support machine sequencing, control logic and interlocking functions.

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 control and signalling paths within automated machinery.

Suitable for OEMs and Panel Builders

The 3RH2911-1HA11 is suitable for OEM machine manufacturers, electrical panel builders, automation integrators and industrial maintenance professionals.

Its 1 NO + 1 NC contact configuration, front mounting and screw terminals make it a practical accessory for expanding compatible Siemens SIRIUS contactor and contactor-relay assemblies.

Key Features

• Siemens SIRIUS auxiliary contact block

• Article number 3RH2911-1HA11

• Front-snap mounting

• 1 NO + 1 NC auxiliary contacts

• All contacts instantaneous

• 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

• 1 NO + 1 NC contacts: Provides two additional auxiliary switching paths.

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

• Screw terminals: Provides a familiar industrial wiring method.

• PLC integration: Supports contactor-status monitoring.

• Interlocking support: The NC contact can be used in suitable interlocking circuits.

• Flexible control logic: NO and NC contacts support different signalling and control functions.

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

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

Why Choose Siemens 3RH2911-1HA11?

The Siemens 3RH2911-1HA11 provides a simple and practical way to add one normally open and one normally closed auxiliary contact to compatible Siemens SIRIUS contactors and contactor relays.

Its front-snap mounting, instantaneous 1 NO + 1 NC arrangement and screw-terminal connections make it suitable for applications requiring additional contactor feedback, signalling, interlocking and machine-control functions. Siemens currently lists the product as an active product.

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 3RH2911-1HA11?

It is a Siemens SIRIUS front-mountable auxiliary contact block with 1 NO and 1 NC contact.

2. How many auxiliary contacts does it provide?

It provides 1 normally open and 1 normally closed auxiliary contact.

3. Are the contacts instantaneous?

Yes. Both contacts are instantaneous.

4. How is it mounted?

It is designed to snap onto the front of 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 auxiliary contacts be used for?

They can be used for PLC feedback, signalling, interlocking, control logic 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 3RH2911-1HA11 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.