Product Description

Siemens 3RB3046-1UB0 Electronic Overload Relay – 12.5–50 A, Class 10E

The Siemens 3RB3046-1UB0 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. The exact Siemens product listing specifies an adjustable current range of 12.5 to 50 A, Class 10E, Size S3, contactor mounting, screw terminals for the main and auxiliary circuits, and manual/automatic reset. Siemens currently lists this article as available for sale.

Siemens SIRIUS 3RB3 Electronic Overload Relay

The 3RB3046-1UB0 belongs to the Siemens SIRIUS 3RB30 electronic overload relay family, developed for protecting motors against overload, phase failure and current asymmetry.

Its electronic and microprocessor-based design continuously evaluates motor current and provides a defined overload response, making it suitable for industrial motor starters and automation 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 12.5–50 A Current Range

The 3RB3046-1UB0 provides an adjustable current-setting range of 12.5 to 50 A. Siemens specifies this exact range for the product.

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

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

Class 10E Trip Characteristic

The exact 3RB3046-1UB0 is a Class 10E electronic overload relay. Siemens identifies this article under the 3RB30 Class 10E range.

Class 10E provides a defined overload tripping characteristic for motors with corresponding starting requirements.

The selected trip class should always be matched to the motor starting time, load characteristics and application requirements.

Electronic Overload Protection

The primary function of the 3RB3046-1UB0 is electronic protection against motor overload.

The relay monitors motor current and responds when the measured condition exceeds the configured overload characteristic.

This can help protect motors against:

• Prolonged overcurrent

• Excessive mechanical loading

• Motor overheating caused by overload

• Abnormal operating conditions

• Excessive motor starting duration

Correct current adjustment is essential for effective motor protection.

Phase-Failure and Asymmetry Protection

The Siemens 3RB30 Class 10E range provides overload, phase-failure and asymmetry protection.

Phase failure or significant current imbalance can cause increased motor heating and operating stress. Electronic monitoring therefore provides broader three-phase motor protection than overload protection alone.

1 NO + 1 NC Auxiliary Contacts

The Siemens 3RB30 Class 10E family provides 1 normally open (NO) and 1 normally closed (NC) auxiliary contact. The auxiliary contacts are used for functions such as contactor disconnection and the “tripped” indication.

These contacts can be incorporated into:

• Contactor-control circuits

• Trip indication

• PLC feedback

• Alarm signalling

• Motor-fault monitoring

• Control-system interlocking

This provides a practical interface between the overload relay and the associated control system.

Contactor Mounting

The 3RB3046-1UB0 is designed for contactor mounting and belongs to Size S3. Siemens explicitly identifies the device as a Size S3, Class 10E electronic overload relay for mounting onto contactors.

This allows it to be integrated with compatible Siemens SIRIUS contactors to form a compact motor-starter assembly.

Typical applications include:

• Motor starters

• Industrial control panels

• Automation cabinets

• OEM machinery

• Process-control systems

Screw-Terminal Connections

The 3RB3046-1UB0 uses screw connections for the main and auxiliary circuits. Siemens identifies both the main circuit and auxiliary circuit as screw-terminal configurations.

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

Manual and Automatic Reset

The exact 3RB3046-1UB0 supports manual and automatic RESET. Siemens specifies both reset options for this article.

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

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

• Control-panel servicing

S3 Compact Design

The 3RB3046-1UB0 is a Size S3 overload relay. The available Siemens datasheet specifies approximately 106 mm height, 70 mm width and 124 mm depth.

The S3 construction is suitable for larger motor-control assemblies where adequate panel space is available.

Electrical and Thermal Characteristics

The product datasheet specifies a 1,000 V insulation voltage and 8 kV surge-voltage resistance for the S3 3RB30 configuration. The device is designed for industrial applications with the corresponding wiring, protection and thermal requirements.

Actual installation should follow Siemens' specified mounting, conductor, protection and operating-temperature requirements.

Industrial Motor-Control Applications

Pumps

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

Fans and Blowers

The Class 10E characteristic can be selected for suitable motors with corresponding starting requirements.

Compressors

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

Conveyors

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

Production Machinery

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

Process Automation

The overload relay can be integrated into automated process systems for motor protection, trip indication and contactor control.

Suitable for OEMs and Panel Builders

The 3RB3046-1UB0 is suitable for OEM machine manufacturers, electrical panel builders, automation integrators and industrial maintenance professionals.

Its combination of 12.5–50 A adjustable current range, Class 10E protection, S3 construction, contactor mounting, screw-terminal 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 3RB3046-1UB0

• Microprocessor-based electronic overload protection

• 12.5–50 A adjustable current range

• Class 10E

• Size S3

• Contactor mounting

• Screw terminals for main and auxiliary circuits

• Overload protection

• Phase-failure protection

• Asymmetry protection

• 1 NO + 1 NC auxiliary contacts

• Manual RESET

• Automatic RESET

• TEST function

• Self-monitoring

• Switch-position indication

• 1,000 V insulation voltage

• 8 kV surge-voltage resistance

Benefits

• 12.5–50 A adjustable range: Suitable for a broad range of industrial motor currents.

• Class 10E: Provides a defined overload characteristic for suitable motor-starting requirements.

• Electronic monitoring: Provides continuous motor-current evaluation.

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

• 1 NO + 1 NC contacts: Provides useful control, signalling and trip-feedback paths.

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

• Screw terminals: Provides a familiar industrial wiring method.

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

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

• S3 construction: Suitable for larger industrial motor-control applications.

Why Choose Siemens 3RB3046-1UB0?

The Siemens 3RB3046-1UB0 is a robust electronic overload relay designed for motor protection in the 12.5–50 A range with a Class 10E trip characteristic. Siemens' current product listing identifies it as a Size S3, contactor-mounted electronic overload relay with screw connections and manual/automatic reset.

Its combination of overload, phase-failure and asymmetry protection, 1 NO + 1 NC auxiliary contacts, TEST/self-monitoring functions and compact S3 construction makes it suitable for industrial motor starters, OEM machinery, automation panels and process equipment.

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 3RB3046-1UB0?

It is a Siemens SIRIUS 3RB3 electronic overload relay with a 12.5–50 A adjustable current range and Class 10E overload characteristic.

2. What is the current setting range?

The adjustable current range is 12.5–50 A.

3. What is the trip class?

The exact 3RB3046-1UB0 is Class 10E.

4. Does it provide phase-failure protection?

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

5. How many auxiliary contacts does it have?

It provides 1 NO + 1 NC auxiliary contacts for control and signalling functions.

6. Is it contactor-mounted?

Yes. The 3RB3046-1UB0 is designed for S3 contactor mounting.

7. Does it use screw terminals?

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

8. What reset options are available?

It supports manual and automatic RESET.

9. Does it have diagnostic functions?

Yes. The 3RB30 family includes TEST functionality, switch-position indication and self-monitoring.

10. Where can I buy Siemens 3RB3046-1UB0 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.