Product Description

Siemens 3RB3026-2SB0 Electronic Overload Relay – 3–12 A, Class 20E

The Siemens 3RB3026-2SB0 is a microprocessor-based electronic overload relay from the Siemens SIRIUS 3RB3 series, designed for reliable motor protection against overload, phase failure and asymmetry. It provides an adjustable current range of 3 to 12 A, a Class 20E trip characteristic, Size S0 construction, and contactor mounting. Siemens specifies screw terminals for both the main and auxiliary circuits, with manual and automatic reset.

Siemens SIRIUS 3RB3 Electronic Overload Relay

The 3RB3026-2SB0 belongs to the Siemens SIRIUS 3RB30 electronic overload relay family, designed for electronic monitoring and protection of three-phase motors.

Its microprocessor-based electronic design provides a defined overload response and additional motor-protection functions. The compact S0 contactor-mounted design allows the relay to be integrated into compatible Siemens SIRIUS motor-starter assemblies.

Typical applications include:

• Industrial motor control

• Pumps

• Fans and blowers

• Compressors

• Conveyors

• Machine tools

• Production machinery

• Process equipment

• Industrial automation

• OEM control panels

Adjustable 3–12 A Current Range

The 3RB3026-2SB0 provides an adjustable current-setting range of 3 to 12 A, with a 12 A thermal current. Siemens' exact datasheet confirms these values.

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

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

Class 20E Trip Characteristic

The exact 3RB3026-2SB0 is a Class 20E electronic overload relay. Siemens identifies this article within the 3RB30 Class 20E range.

The Class 20E characteristic provides a defined overload tripping response for motors with corresponding starting requirements. The selected trip class should be matched to the motor's starting time and application conditions.

Electronic Overload Protection

The primary function of the 3RB3026-2SB0 is electronic motor-overload protection.

The relay continuously evaluates motor current and responds when the configured overload characteristic is exceeded.

This helps protect motors against:

• Prolonged overcurrent

• Excessive mechanical loading

• Motor overheating caused by overload

• Abnormal operating conditions

• Extended motor starting duration

Correct adjustment of the current setting is important for dependable motor protection.

Phase-Failure and Asymmetry Protection

The Siemens 3RB30 Class 20E range provides overload, phase-failure and asymmetry protection. These functions help protect three-phase motors against abnormal current conditions that can cause excessive heating.

Phase-failure protection is particularly useful because operation with a missing phase can lead to unbalanced current and additional thermal stress.

1 NO + 1 NC Auxiliary Contacts

The 3RB3026-2SB0 uses the standard 1 NO + 1 NC auxiliary-contact arrangement of the Siemens 3RB30 Class 20E range. The auxiliary contacts can be used for contactor control, trip indication, PLC feedback and signalling.

Typical applications include:

• Contactor-control circuits

• Trip indication

• PLC feedback

• Alarm signalling

• Motor fault monitoring

• Control-system interlocking

These contacts provide a convenient interface between the overload relay and the associated control system.

Contactor Mounting

The 3RB3026-2SB0 is designed for contactor mounting and belongs to Size S0. Siemens identifies the product as an S0 overload relay for contactor mounting.

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

The exact contactor compatibility should be verified before installation.

Screw-Terminal Connections

The 3RB3026-2SB0 uses screw terminals for both the main and auxiliary circuits. Siemens' exact datasheet specifies screw connections for both circuits.

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

Manual and Automatic Reset

The exact 3RB3026-2SB0 supports manual and automatic RESET. Siemens specifies both reset modes for this article.

The datasheet specifies a typical recovery time of approximately 3 minutes after an overload trip with automatic reset, while manual and remote reset conditions have a typical recovery time of 0 minutes under the applicable conditions.

The reset mode should be selected according to the motor-control and machine requirements.

TEST Function and Self-Monitoring

The Siemens 3RB30 Class 20E range includes TEST functionality, switch-position indication and self-monitoring.

These functions can support:

• Commissioning

• Functional testing

• Troubleshooting

• Preventive maintenance

• Control-panel servicing

Electrical and Environmental Characteristics

The 3RB3026-2SB0 has an insulation voltage of 690 V and a surge-voltage resistance of 6 kV. Siemens specifies approximately 0.6 W total power loss at rated current in the hot operating state, or 0.2 W per pole.

The specified operating ambient temperature range is -25 °C to +60 °C, with temperature compensation across this range. The maximum installation altitude is 2,000 m under the specified conditions.

These parameters should be considered during motor-control-panel design and installation.

Compact S0 Design

The 3RB3026-2SB0 is a compact S0-size overload relay. Siemens' technical specifications place the S0 relay family at approximately 45 mm width, with dimensions depending on the exact mounting arrangement.

The compact construction is suitable for:

• Motor starters

• Automation cabinets

• Machine-control panels

• OEM electrical assemblies

• Industrial motor-control systems

Industrial Motor-Control Applications

Pumps

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

Fans and Blowers

The Class 20E characteristic can be used for motors with corresponding starting requirements.

Compressors

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

Conveyors

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

Machine Tools

Its compact S0 design is suitable for machine-control panels and motor starters.

Process Automation

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

Suitable for OEMs and Panel Builders

The 3RB3026-2SB0 is suitable for OEM machine manufacturers, electrical panel builders, automation integrators and industrial maintenance professionals.

Its combination of 3–12 A adjustable current range, Class 20E protection, S0 contactor mounting, 1 NO + 1 NC auxiliary contacts, screw-terminal connections and manual/automatic reset makes it suitable for compact industrial motor-protection systems.

Key Features

• Siemens SIRIUS 3RB3 electronic overload relay

• Article number 3RB3026-2SB0

• Microprocessor-based electronic overload protection

• 3–12 A adjustable current range

• Class 20E

• Size S0

• Contactor mounting

• Screw terminals for main and auxiliary circuits

• 1 NO + 1 NC auxiliary contacts

• Overload protection

• Phase-failure protection

• Asymmetry protection

• Manual RESET

• Automatic RESET

• TEST function

• Self-monitoring

• Switch-position indication

• 690 V insulation voltage

• 6 kV surge-voltage resistance

Benefits

• 3–12 A adjustable range: Suitable for motors within the specified current range.

• Class 20E: Provides a defined overload characteristic for compatible motor-starting requirements.

• Electronic monitoring: Provides continuous motor-current evaluation.

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

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

• Contactor mounting: Supports compact S0 motor-starter assemblies.

• Screw terminals: Provides a familiar industrial wiring method.

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

• TEST and self-monitoring: Support commissioning and maintenance.

• Compact S0 construction: Helps optimize control-panel space.

Why Choose Siemens 3RB3026-2SB0?

The Siemens 3RB3026-2SB0 is a compact electronic overload relay for motor protection in the 3–12 A range with a Class 20E trip characteristic.

Its combination of electronic overload, phase-failure and asymmetry protection, S0 contactor mounting, 1 NO + 1 NC auxiliary contacts, screw connections and manual/automatic reset makes it suitable for industrial motor starters, OEM machinery and automation panels.

The exact Siemens datasheet confirms the 3–12 A current range, Class 20E rating, S0 size, contactor mounting, screw terminals and manual/automatic reset, making this model suitable for compatible industrial motor-protection 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 3RB3026-2SB0?

It is a Siemens SIRIUS 3RB3 electronic overload relay for motor protection with a 3–12 A adjustable current range and Class 20E characteristic.

2. What is the current setting range?

The adjustable current range is 3–12 A.

3. What is the trip class?

The exact 3RB3026-2SB0 is Class 20E.

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.

6. Is it contactor-mounted?

Yes. The 3RB3026-2SB0 is designed for S0 contactor mounting.

7. Does it use screw terminals?

Yes. Siemens specifies screw-type terminals for both the main and auxiliary circuits.

8. What reset options are available?

It supports manual and automatic RESET.

9. Does it have diagnostic functions?

Yes. Siemens specifies TEST functionality, switch-position indication and self-monitoring for the 3RB30 Class 20E range.

10. Where can I buy Siemens 3RB3026-2SB0 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.