Product Description

Siemens 3RH2921-1DA11 Auxiliary Contact Block – Lateral Mounting

The Siemens 3RH2921-1DA11 is a laterally mountable auxiliary contact block from the Siemens SIRIUS accessory range, designed for compatible contactors and contactor relays. It provides additional auxiliary switching contacts for control, signalling, interlocking and feedback applications without changing the main power-switching function of the connected contactor.

Its lateral mounting arrangement allows the accessory to be installed on the left and/or right side of compatible devices, making it suitable for compact industrial control-panel configurations.

Siemens SIRIUS Auxiliary Contact Block

The 3RH2921-1DA11 is designed to expand the auxiliary-contact functionality of compatible Siemens SIRIUS contactors and contactor relays.

Auxiliary contacts provide additional electrical switching paths that can be used independently from the main power contacts for control and monitoring functions.

Typical applications include:

• Contactor status feedback

• PLC input signals

• Electrical interlocking

• Control-circuit logic

• Machine sequencing

• Auxiliary signalling

• Motor-control circuits

• Industrial automation

Laterally Mountable Design

A key feature of the 3RH2921-1DA11 is its lateral mounting design.

The auxiliary contact block can be installed on the left and/or right side of compatible SIRIUS devices, allowing panel builders to add auxiliary functionality without significantly increasing the front-panel footprint.

This can be particularly useful in:

• Compact control panels

• Motor starters

• Machine-control cabinets

• Automation panels

• OEM equipment

• Industrial control assemblies

Compatibility should always be checked against the exact contactor or contactor-relay article number before installation.

Additional Auxiliary Switching

The purpose of the 3RH2921-1DA11 is to provide additional contacts for control and signalling functions.

Depending on the complete circuit configuration, auxiliary contacts can be used for:

• Contactor ON/OFF feedback

• PLC monitoring

• Electrical interlocking

• Relay logic

• Machine sequencing

• Status indication

• Alarm signalling

• Control-system feedback

The auxiliary contacts should only be used within their specified electrical ratings.

Industrial Automation Integration

The 3RH2921-1DA11 can form part of a complete industrial control system alongside:

• Siemens contactors

• Contactor relays

• PLCs

• HMIs

• Overload relays

• Circuit breakers

• Pushbuttons

• Selector switches

• Control relays

• Motor-protection devices

For example, an auxiliary contact can provide a status signal from a contactor to a PLC without interrupting the main load circuit.

Applications

The Siemens 3RH2921-1DA11 can be used in:

• Industrial automation

• Motor-control panels

• Machine-control systems

• Production machinery

• Conveyor systems

• Pumping systems

• Packaging machines

• Process automation

• Electrical control cabinets

• OEM machinery

• PLC-based control systems

• Industrial operator panels

For related Siemens industrial electrical and automation products, customers can explore the Siemens product range at SB Smart.

Suitable for OEMs and Panel Builders

The 3RH2921-1DA11 is suitable for OEM machine manufacturers, electrical panel builders, automation integrators and industrial maintenance professionals.

Its lateral mounting arrangement provides flexibility when additional auxiliary switching functionality is required within a compact control-panel design.

Key Features

• Siemens SIRIUS accessory

• Article number 3RH2921-1DA11

• Laterally mountable auxiliary contact block

• Mounting on left and/or right side

• Designed for compatible Siemens contactors and contactor relays

• Suitable for auxiliary control circuits

• Suitable for PLC feedback

• Suitable for electrical interlocking

• Suitable for machine sequencing

• Suitable for industrial automation

• Suitable for OEM machinery

• Suitable for electrical control panels

Benefits

• Lateral mounting: Allows auxiliary contacts to be added from the side of compatible devices.

• Space-efficient design: Helps optimize control-panel layouts.

• Additional control functionality: Provides extra switching paths for signalling and automation.

• PLC integration: Can be used for contactor-status feedback.

• Interlocking support: Suitable for control-system interlocking arrangements.

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

• OEM-friendly: Suitable for standardized machine-control designs.

• Industrial suitability: Designed for Siemens SIRIUS control assemblies.

Why Choose Siemens 3RH2921-1DA11?

The Siemens 3RH2921-1DA11 provides a practical way to expand the auxiliary functionality of compatible Siemens SIRIUS contactors and contactor relays.

Its laterally mountable design allows additional control and signalling capability to be integrated on the left and/or right side of compatible devices, helping panel builders maintain a compact and organized control-panel layout.

It is suitable for applications requiring PLC feedback, interlocking, auxiliary signalling and machine-control logic.

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 3RH2921-1DA11?

It is a laterally mountable auxiliary contact block from the Siemens SIRIUS accessory range.

2. Where is it mounted?

It is designed for lateral mounting on the left and/or right side of compatible Siemens devices.

3. What is an auxiliary contact block used for?

It provides additional switching paths for feedback, signalling, interlocking and control-circuit functions.

4. Can it be used for PLC feedback?

Yes. Suitable auxiliary contacts can be connected to PLC digital inputs for status monitoring.

5. Can it be used for electrical interlocking?

Yes. Auxiliary contacts can be incorporated into suitable interlocking circuits.

6. Does it switch the main motor power?

No. An auxiliary contact block provides control and signalling contacts; the main load is switched by the compatible contactor.

7. Is it suitable for compact control panels?

Yes. Its lateral mounting arrangement is useful where panel space and organized device layout are important.

8. Is it suitable for OEM machinery?

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

9. What should be checked before installation?

The exact compatibility, contact configuration, mounting arrangement and electrical ratings should be verified against the connected Siemens device and the manufacturer's documentation.

10. Where can I buy Siemens 3RH2921-1DA11 in India?

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