Product Description

Siemens 3RB3046-2XB0 Electronic Overload Relay – 32–115 A, Class 20E

The Siemens 3RB3046-2XB0 is a microprocessor-based electronic overload relay from the Siemens SIRIUS 3RB3 series, designed for reliable motor protection against overload, phase failure and phase asymmetry. It provides an adjustable current range of 32 to 115 A, a Class 20E trip characteristic, S3 size, and contactor mounting. Siemens specifies screw terminals for both the main and auxiliary circuits and manual/automatic reset for this exact article.

Siemens SIRIUS 3RB3 Electronic Overload Relay

The 3RB3046-2XB0 is part of the Siemens SIRIUS electronic overload-relay family, developed for motor protection applications where electronic current monitoring and a defined overload characteristic are required.

The relay is designed for use with compatible Siemens SIRIUS 3RT contactors and is suitable for industrial motor starters and control systems.

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 3RB3046-2XB0 provides an adjustable current-setting range of 32 to 115 A. Siemens specifies 115 A as the thermal current for the device.

The current setting should be adjusted according to the protected motor's rated current and the requirements of the complete motor-protection system.

This wide setting range makes the relay suitable for a variety of larger industrial motor applications.

Class 20E Trip Characteristic

The 3RB3046-2XB0 uses a Class 20E overload characteristic. Siemens identifies the exact article as a Class 20E electronic overload relay.

The Class 20E characteristic is suitable for applications where the motor requires a corresponding longer starting tolerance than lower trip classes.

The selected overload characteristic should always be matched to the motor starting time and application requirements.

Electronic Overload Protection

The primary function of the 3RB3046-2XB0 is electronic motor-overload protection.

The relay monitors motor current and evaluates excessive current conditions electronically. When the configured overload characteristic is exceeded, the auxiliary contacts can initiate the associated contactor-control response.

This helps protect motors against:

• Prolonged overcurrent

• Excessive mechanical loading

• Motor overheating caused by overload

• Abnormal operating conditions

• Excessive starting duration

Correct current adjustment is essential for effective motor protection.

Phase-Failure and Phase-Asymmetry Protection

The Siemens 3RB30 electronic overload relay family provides overload, phase-failure and phase-asymmetry protection. These functions help protect three-phase motors against abnormal current conditions that can cause excessive heating.

Phase-failure protection is especially important because operating a three-phase motor with a missing phase can result in abnormal current and thermal stress.

1 NO + 1 NC Auxiliary Contacts

The 3RB3046-2XB0 provides auxiliary contacts for the motor-control circuit. Siemens identifies the 3RB30 range with 1 NO + 1 NC auxiliary contacts for control and signalling functions.

These auxiliary contacts can be used for:

• Contactor control

• Trip indication

• PLC feedback

• Alarm signalling

• Motor fault monitoring

• Control-system interlocking

The auxiliary contacts provide a convenient interface between the overload relay and the associated contactor/control circuit.

Contactor Mounting

The 3RB3046-2XB0 is designed for contactor mounting and is intended for S3-size contactor assemblies. Siemens specifies the compatible contactor size as S3.

This allows the overload relay to be installed directly with compatible SIRIUS contactors, helping create a compact motor-starter arrangement.

Screw-Terminal Connections

The 3RB3046-2XB0 uses screw terminals for the main and auxiliary circuits. Siemens explicitly specifies screw connections for both circuits.

This provides a conventional connection method for industrial panel builders and maintenance teams.

Manual and Automatic Reset

The exact 3RB3046-2XB0 supports manual and automatic reset. Siemens specifies the reset capability in the official product description.

Manual reset can be selected where operator intervention is required after an overload trip, while automatic reset can be used where permitted by the overall control-system design.

Siemens specifies a typical recovery time of approximately 3 minutes after an overload trip with automatic reset, while manual reset has a typical recovery time of 0 minutes.

TEST Function and Self-Monitoring

The Siemens 3RB30 electronic overload-relay family incorporates diagnostic functions including TEST functionality, switch-position indication and self-monitoring.

These functions can support:

• Commissioning

• Functional testing

• Troubleshooting

• Preventive maintenance

• Motor-control panel servicing

S3 Size and Electrical Characteristics

The 3RB3046-2XB0 is a Size S3 overload relay. Siemens specifies 1,000 V insulation voltage, 8 kV surge-voltage resistance, and approximately 4.6 W total power loss at rated current in the hot operating state.

These electrical and thermal characteristics should be considered when designing the motor-control panel and selecting associated equipment.

The product is specified for operation from -25 °C to +60 °C under the relevant temperature-compensation conditions.

Industrial Motor-Control Applications

Pumps

The relay can protect compatible pump motors against overload, phase failure and current asymmetry.

Fans and Blowers

The Class 20E characteristic can be applied to suitable motors according to their starting requirements.

Compressors

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

Conveyors

It can protect conveyor motors against excessive mechanical loading and phase-related abnormalities.

Production Machinery

The S3-size construction makes it suitable for larger industrial motor-control assemblies.

Process Automation

The relay can be integrated into automated motor-control systems where overload monitoring and contactor shutdown are required.

Suitable for OEMs and Panel Builders

The 3RB3046-2XB0 is suitable for OEM machine manufacturers, electrical panel builders, automation integrators and industrial maintenance professionals.

Its combination of 32–115 A adjustable current, Class 20E protection, phase-failure and asymmetry protection, S3 construction, contactor mounting, screw connections and manual/automatic reset makes it suitable for a wide range of industrial motor-protection applications.

Key Features

• Siemens SIRIUS 3RB3 electronic overload relay

• Article number 3RB3046-2XB0

• Microprocessor-based electronic overload protection

• 32–115 A adjustable current range

• Class 20E

• S3 size

• Contactor mounting

• Screw terminals for main and auxiliary circuits

• Overload protection

• Phase-failure protection

• Phase-asymmetry protection

• 1 NO + 1 NC auxiliary contacts

• Manual RESET

• Automatic RESET

• TEST functionality

• Self-monitoring

• Switch-position indication

• 1,000 V insulation voltage

• 8 kV surge-voltage resistance

Benefits

• Microprocessor-based electronic protection: Provides continuous electronic monitoring of motor current.

• 32–115 A adjustable range: Suitable for larger industrial motor applications.

• Class 20E: Provides an appropriate overload characteristic for suitable motor-starting conditions.

• Phase protection: Helps protect against phase failure and asymmetry.

• 1 NO + 1 NC auxiliary contacts: Provides control and trip-feedback functions.

• Contactor mounting: Supports compact S3 motor-starter assemblies.

• Screw connections: Provides a familiar industrial wiring method.

• Manual/automatic reset: Supports different motor-control strategies.

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

Why Choose Siemens 3RB3046-2XB0?

The Siemens 3RB3046-2XB0 is a robust electronic overload relay for motor protection in the 32–115 A range with a Class 20E trip characteristic.

Its combination of electronic overload protection, phase-failure and asymmetry protection, S3 contactor mounting, 1 NO + 1 NC auxiliary contacts and manual/automatic reset makes it suitable for industrial motor starters, automation panels and OEM machinery.

Siemens currently lists the 3RB3046-2XB0 as an active product, making it suitable for procurement where this exact configuration is required.

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 3RB3046-2XB0?

It is a Siemens SIRIUS 3RB3 electronic overload relay for motor protection with a 32–115 A adjustable current range and Class 20E characteristic.

2. What is the current setting range?

The adjustable current range is 32–115 A.

3. What is the trip class?

The exact 3RB3046-2XB0 is Class 20E.

4. Does it provide phase-failure protection?

Yes. The 3RB30 range provides phase-failure and asymmetry protection in addition to overload protection.

5. How many auxiliary contacts does it have?

The 3RB30 range provides 1 NO + 1 NC auxiliary contacts for control and signalling functions.

6. Is it contactor-mounted?

Yes. The 3RB3046-2XB0 is designed for S3 contactor mounting.

7. Does it use screw terminals?

Yes. Siemens specifies screw connections for both the main and auxiliary circuits.

8. What reset options are available?

It supports manual and automatic reset.

9. Where can the 3RB3046-2XB0 be used?

It can be used in industrial motor starters, pumps, fans, compressors, conveyors, production machinery, process equipment and automation panels.

10. Where can I buy Siemens 3RB3046-2XB0 in India?

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