Product Description

Siemens 3RB3133-4WB0 Electronic Overload Relay – 20–80 A, Class 5E–30E

The Siemens 3RB3133-4WB0 is a microprocessor-based electronic overload relay from the Siemens SIRIUS 3RB3 series, designed for reliable motor protection in industrial automation and motor-control systems. It provides an adjustable current setting of 20–80 A, selectable trip classes 5E, 10E, 20E and 30E, and is designed for contactor mounting in Size S2. Siemens specifies screw terminals for both the main and auxiliary circuits, along with manual/automatic reset and internal ground-fault detection.

The relay provides electronic overload, phase-failure and asymmetry protection, making it suitable for protecting three-phase motors against common abnormal operating conditions. Siemens also specifies integrated electrical remote reset, a TEST function, switch-position indication and self-monitoring for the 3RB31 family.

Siemens SIRIUS 3RB3 Electronic Overload Relay

The 3RB3133-4WB0 belongs to the Siemens SIRIUS 3RB3 electronic overload relay family, which is designed for motor protection applications where accurate electronic current monitoring and adjustable trip characteristics are required.

Unlike conventional thermal overload relays, electronic overload relays use electronic measurement and processing to determine overload conditions and provide configurable protection 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 20–80 A Current Range

The 3RB3133-4WB0 provides an adjustable current range of 20 to 80 A.

This allows the relay to be configured according to the rated current of the protected motor.

The current setting should be selected using the motor nameplate current and the requirements of the complete motor-protection system. Correct adjustment is important to provide effective overload protection without causing unnecessary trips during normal operation.

Selectable Class 5E–30E

The relay supports four selectable trip classes:

• Class 5E

• Class 10E

• Class 20E

• Class 30E

Siemens identifies these classes as adjustable features of the 3RB31 electronic overload relay range.

The selectable trip class allows the overload relay to be matched to different motor starting characteristics and application requirements. A suitable class should be selected based on the motor's starting time and operating conditions.

Electronic Overload Protection

The main purpose of the 3RB3133-4WB0 is to protect motors against overload conditions.

The relay continuously evaluates motor current and initiates a trip when the measured condition exceeds the configured overload characteristics.

This can help protect against:

• Prolonged overcurrent

• Excessive mechanical loading

• Motor overheating caused by overload

• Abnormal operating conditions

• Extended motor starting conditions when the selected class is inappropriate

Phase-Failure and Asymmetry Protection

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

Phase-related abnormalities can create unbalanced current and additional motor heating. Electronic monitoring therefore provides broader motor protection than overload-only operation.

This makes the 3RB3133-4WB0 suitable for three-phase motor applications in industrial equipment.

Internal Ground-Fault Detection

The 3RB3 electronic overload relay family includes activatable internal ground-fault detection. Siemens specifically lists internal ground-fault detection among the protection functions of the 3RB31 range.

This can provide an additional layer of motor protection in compatible applications.

The complete protection system should still be selected and designed according to the installation's electrical protection requirements.

Manual, Automatic and Remote Reset

The 3RB3133-4WB0 supports flexible reset options as part of the 3RB31 product family.

Available functions include:

• Manual RESET

• Automatic RESET

• Integrated electrical remote RESET

These options allow the relay to be incorporated into different control strategies, from operator-controlled resetting to suitable automated reset systems.

TEST Function and Self-Monitoring

The 3RB31 range includes a TEST function and self-monitoring capability.

These features can assist during:

• Commissioning

• Troubleshooting

• Preventive maintenance

• Functional testing

• Control-panel servicing

The switch-position indication also provides a useful visual reference for the relay's operating state.

1 NO + 1 NC Auxiliary Contacts

The 3RB3133-4WB0 incorporates 1 normally open (NO) and 1 normally closed (NC) auxiliary contact.

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

• Contactor disconnection

• Trip indication

• PLC feedback

• Alarm signalling

• Control-system interlocking

• Motor fault monitoring

The NO contact is used for the tripped indication, while the NC contact can be used for the appropriate contactor-disconnection/control function.

Contactor Mounting

The 3RB3133-4WB0 is designed for contactor mounting in Size S2. Siemens' current datasheet explicitly identifies the relay as a 20–80 A electronic overload relay for motor protection with S2 contactor mounting.

This makes it suitable for integration into compatible Siemens SIRIUS contactor and motor-starter assemblies.

Screw-Terminal Connections

The 3RB3133-4WB0 uses screw terminals for both the main and auxiliary circuits.

This provides a conventional connection method for industrial panel builders and maintenance teams and supports integration into standard motor-control assemblies.

Size S2 Design

The relay is a Size S2 overload relay. Siemens specifies an approximate 4.6 W total power loss at rated current in the hot operating state, which is relevant when considering enclosure thermal conditions.

The relay is suitable for industrial motor-control panels where the overload relay is combined with a compatible contactor.

Industrial Motor-Control Applications

The 3RB3133-4WB0 can be used in a wide range of industrial motor-protection applications.

Pumps

It can protect compatible pump motors against overload, phase-failure and asymmetry conditions.

Fans and Blowers

The adjustable trip classes allow protection characteristics to be selected according to the motor starting and operating conditions.

Compressors

Electronic overload protection can help protect compressor motors from excessive operating current.

Conveyors

It can protect conveyor motors from overload and phase-related abnormalities.

Machine Tools

The relay can be incorporated into motor-control panels for industrial machinery and production equipment.

Process Automation

Its electronic protection, reset options and auxiliary signalling make it suitable for automated process equipment.

Suitable for OEMs and Panel Builders

The 3RB3133-4WB0 is suitable for OEM machine manufacturers, electrical panel builders, automation integrators and industrial maintenance professionals.

Its combination of 20–80 A adjustable current, Class 5E–30E selectable trip characteristics, phase-failure protection, asymmetry protection, internal ground-fault detection, flexible reset functions and contactor mounting makes it suitable for a wide range of industrial motor-protection applications.

Key Features

• Siemens SIRIUS 3RB3 electronic overload relay

• Article number 3RB3133-4WB0

• Microprocessor-based electronic overload protection

• 20–80 A adjustable current range

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

• Contactor mounting

• Size S2

• Overload protection

• Phase-failure protection

• Asymmetry protection

• Activatable internal ground-fault detection

• 1 NO + 1 NC auxiliary contacts

• Manual and automatic RESET

• Integrated electrical remote RESET

• TEST function

• Self-monitoring

• Switch-position indication

• Screw terminals for main and auxiliary circuits

Benefits

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

• 20–80 A adjustable range: Covers a broad range of compatible motor currents.

• Class 5E–30E selection: Allows the trip characteristic to be matched to motor starting requirements.

• Phase protection: Helps detect phase failure and asymmetry conditions.

• Ground-fault detection: Adds 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 control and trip-feedback signals.

• Contactor mounting: Allows integration into compatible SIRIUS motor-starter assemblies.

• Screw connections: Provides a familiar industrial wiring solution.

Why Choose Siemens 3RB3133-4WB0?

The Siemens 3RB3133-4WB0 is a versatile electronic overload relay for applications requiring adjustable motor protection in the 20–80 A range.

Its Class 5E, 10E, 20E and 30E selectable trip characteristics allow the protection settings to be adapted to different motor starting conditions. The relay also combines overload protection with phase-failure and asymmetry protection, plus activatable internal ground-fault detection.

With 1 NO + 1 NC auxiliary contacts, manual/automatic/remote reset, TEST functionality, self-monitoring and S2 contactor mounting, the relay provides a comprehensive protection and control solution for industrial motor starters.

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 3RB3133-4WB0?

It is a Siemens SIRIUS 3RB3 electronic overload relay for motor protection with a 20–80 A adjustable current range and Class 5E–30E selectable trip classes.

2. What is the current setting range?

The adjustable current range is 20–80 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 detection?

Yes. The 3RB31 family provides activatable internal ground-fault detection.

6. How many auxiliary contacts does it have?

It has 1 NO + 1 NC auxiliary contacts.

7. What reset options are available?

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

8. Is it contactor-mounted?

Yes. The 3RB3133-4WB0 is designed for S2 contactor mounting.

9. What type of terminals are used?

The product uses screw terminals for both the main and auxiliary circuits.

10. Where can I buy Siemens 3RB3133-4WB0 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.