Product Description

Siemens 3RB3143-4XW1 Electronic Overload Relay – 32–115 A, Class 5E–30E

The Siemens 3RB3143-4XW1 is a microprocessor-based electronic overload relay from the Siemens SIRIUS 3RB3 series, designed for reliable motor protection in industrial electrical and automation systems. It provides an adjustable current range of 32 to 115 A and selectable trip classes 5E, 10E, 20E and 30E. The device is designed for stand-alone installation, with a straight-through transformer on the main circuit and screw terminals for the auxiliary circuit.

The electronic design provides overload, phase-failure and asymmetry protection, with additional internal ground-fault detection capability. Siemens also specifies manual and automatic reset, an integrated electrical remote-reset function, switch-position indication, TEST functionality and self-monitoring.

Siemens SIRIUS 3RB3 Electronic Overload Relay

The 3RB3143-4XW1 is part of the Siemens SIRIUS 3RB electronic overload relay family, developed for protecting three-phase motors and compatible industrial loads against excessive current conditions.

Unlike traditional thermal overload relays, electronic overload relays use electronic measurement and microprocessor-based evaluation to provide more precise motor protection and configurable trip characteristics.

Typical applications include:

• Industrial motor control

• Pumps

• Fans and blowers

• Compressors

• Conveyors

• Machine tools

• Production machinery

• Process equipment

• Industrial automation

• OEM control panels

Adjustable 32–115 A Current Range

The 3RB3143-4XW1 has a broad adjustable current range of 32–115 A, allowing the relay to be set according to the rated operating current of the motor being protected. Siemens identifies this exact current range for the 3RB3143-4XW1.

The current setting should be selected according to the motor nameplate data and the requirements of the complete motor-protection system.

Selectable Class 5E–30E

One of the key features of the relay is its selectable trip class.

The 3RB3143-4XW1 supports:

• Class 5E

• Class 10E

• Class 20E

• Class 30E

These adjustable trip classes allow the overload relay to be matched more closely to different motor starting characteristics and applications. Siemens lists these four selectable trip classes for the 3RB31 range.

This flexibility is particularly useful for applications with different starting times and motor-load characteristics.

Overload Protection

The primary purpose of the 3RB3143-4XW1 is to protect motors against overload conditions.

The electronic relay continuously monitors the motor current and trips when the measured condition exceeds the configured protection characteristics.

This can help protect the motor against:

• Prolonged overcurrent

• Excessive mechanical loading

• Abnormal operating conditions

• Motor overheating caused by overload

The relay should be correctly set according to the actual motor full-load current.

Phase-Failure and Asymmetry Protection

The 3RB3 electronic overload relay family provides protection against phase failure and phase asymmetry in addition to overload protection. Siemens lists these functions as standard features of the 3RB31 range.

These functions are important in three-phase motor applications because an abnormal phase condition can result in increased current and overheating.

The relay can therefore provide broader motor protection than a simple overload-only device.

Internal Ground-Fault Detection

The 3RB31 family also provides internal ground-fault detection, which Siemens identifies as an activatable function.

This can help detect certain ground-fault conditions without requiring a separate external ground-fault detection device in suitable applications.

The complete protection scheme should nevertheless be designed according to the application's electrical and safety requirements.

Manual, Automatic and Remote Reset

The 3RB3143-4XW1 supports flexible reset options.

The Siemens 3RB31 range provides:

• Manual RESET

• Automatic RESET

• Integrated electrical remote RESET

This allows the relay to be incorporated into different machine-control strategies.

Manual reset can be useful where operator intervention is required after a trip, while automatic or remote reset can be incorporated into suitable automated control systems.

TEST Function and Self-Monitoring

The relay includes a TEST function and self-monitoring capability. Siemens identifies both as features of the 3RB31 electronic overload relay family.

These functions can be useful during:

• Commissioning

• Preventive maintenance

• Troubleshooting

• Functional checks

• Control-panel servicing

Self-monitoring can help identify certain internal device conditions and improve diagnostic capability.

1 NO + 1 NC Auxiliary Contacts

The 3RB3143-4XW1 provides 1 normally open and 1 normally closed auxiliary contact.

These contacts can be incorporated into the motor-control circuit for:

• Contactor control

• Fault signalling

• Motor trip indication

• PLC feedback

• Alarm circuits

• Control-system interlocking

This allows the overload relay to communicate its operating state to other control components.

Stand-Alone Installation

The 3RB3143-4XW1 is designed for stand-alone installation rather than direct contactor mounting. Siemens identifies it as a stand-alone S3 overload relay with a straight-through transformer in the main circuit.

This configuration can be useful when the overload relay needs to be installed separately from the contactor or integrated into a customized control-panel arrangement.

Screw-Terminal Auxiliary Connection

The auxiliary and control circuit uses screw-type terminals. The product data identifies the auxiliary connection as a screw-terminal configuration.

This provides a conventional connection method for industrial electrical panels and simplifies integration with contactors, PLCs and signalling circuits.

S3 Compact Industrial Design

The 3RB3143-4XW1 is a Size S3 overload relay. Its stand-alone housing is suitable for industrial control cabinets and motor-control panels.

The specified dimensions are approximately:

• Height: 106 mm

• Width: 70 mm

• Depth: 124 mm

These dimensions provide a compact solution for the 32–115 A protection range while allowing the necessary electrical connections and thermal design.

Industrial Motor-Control Applications

The 3RB3143-4XW1 can be used in a wide range of industrial motor-protection applications.

Pumps

It can protect motors driving industrial and process pumps against overload and phase-related operating conditions.

Fans and Blowers

The adjustable trip class can be selected according to the motor starting characteristics and application requirements.

Compressors

Electronic overload protection is useful for motors operating under variable mechanical load conditions.

Conveyors

The relay can protect conveyor motors against excessive loading and abnormal phase conditions.

Machine Tools

It can be incorporated into motor-control panels for industrial machine tools and production machinery.

Process Automation

Its electronic protection and auxiliary signalling functions make it suitable for automated process equipment.

Suitable for OEMs and Panel Builders

The 3RB3143-4XW1 is suitable for OEM machine manufacturers, electrical panel builders, automation integrators and industrial maintenance professionals.

Its combination of 32–115 A adjustable current range, Class 5E–30E selection, overload protection, phase-failure protection, asymmetry protection, ground-fault detection, flexible reset options and stand-alone installation makes it suitable for demanding industrial motor-protection systems.

Key Features

• Siemens SIRIUS 3RB3 electronic overload relay

• Article number 3RB3143-4XW1

• Microprocessor-based electronic overload protection

• 32–115 A adjustable current range

• Class 5E, 10E, 20E and 30E adjustable

• Overload protection

• Phase-failure protection

• Asymmetry protection

• Activatable internal ground-fault detection

• 1 NO + 1 NC auxiliary contacts

• Manual and automatic RESET

• Electrical remote RESET

• TEST function

• Self-monitoring

• Switch-position indication

• Size S3

• Stand-alone installation

• Straight-through transformer main circuit

• Screw terminals for auxiliary circuit

Benefits

• Microprocessor-based protection: Provides electronic evaluation for accurate motor protection.

• Wide 32–115 A range: Suitable for a broad range of industrial motor currents.

• Adjustable Class 5E–30E: Allows selection according to motor starting characteristics.

• Phase protection: Helps protect motors from phase failure and asymmetry.

• Ground-fault detection: Provides an additional protection function when activated.

• Flexible reset: Supports manual, automatic and remote reset strategies.

• Diagnostic functions: TEST and self-monitoring support commissioning and maintenance.

• Auxiliary signalling: 1 NO + 1 NC contacts provide useful control and fault-feedback signals.

• Stand-alone installation: Suitable for customized motor-control panel layouts.

Why Choose Siemens 3RB3143-4XW1?

The Siemens 3RB3143-4XW1 is a versatile electronic overload relay for industrial motor protection where adjustable current settings and flexible trip characteristics are required.

Its 32–115 A adjustable range and Class 5E, 10E, 20E and 30E settings allow the protection characteristics to be matched to different motor starting requirements. It also combines overload, phase-failure and asymmetry protection with activatable ground-fault detection, flexible reset modes and diagnostic functions.

For OEMs, panel builders and automation integrators, the relay provides a comprehensive protection solution for stand-alone motor-control applications.

Delivery Across India

SB Smart supplies Siemens industrial electrical and automation products across Faridabad, Gurgaon/Gurugram, Delhi NCR, Haryana, Noida, Punjab, Mumbai and 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 3RB3143-4XW1?

It is a Siemens SIRIUS 3RB3 electronic overload relay designed for motor protection, with a 32–115 A adjustable current range and Class 5E–30E selectable trip classes.

2. What is the current setting range?

The adjustable current range is 32–115 A.

3. Which trip classes are available?

The relay supports Class 5E, 10E, 20E and 30E with selectable settings.

4. Does it provide phase-failure protection?

Yes. The 3RB31 family provides phase-failure and asymmetry protection in addition to overload protection.

5. Does it have ground-fault protection?

It provides internal ground-fault detection, which can be activated when required.

6. How many auxiliary contacts does it have?

It provides 1 NO + 1 NC auxiliary contacts.

7. What reset options are available?

The 3RB31 range supports manual, automatic and electrical remote RESET.

8. Is the relay contactor-mounted?

The 3RB3143-4XW1 is designed for stand-alone installation and uses straight-through transformers in the main circuit.

9. What type of terminals are used?

The auxiliary and control circuit uses screw-type terminals.

10. Where can I buy Siemens 3RB3143-4XW1 in India?

You can explore the Siemens industrial electrical and automation product range at SB Smart for electronic overload relays, contactors, motor-protection devices and related control components.