Product Description

Siemens 3RB3026-2QB0 Electronic Overload Relay – 6–25 A, Class 20E

The Siemens 3RB3026-2QB0 is a microprocessor-based electronic overload relay from the Siemens SIRIUS 3RB3 series, designed for motor protection against overload, phase failure and asymmetry. It provides an adjustable current range of 6 to 25 A, a Class 20E trip characteristic, Size S0 construction and contactor mounting. The exact Siemens datasheet specifies screw terminals for the main and auxiliary circuits and manual/automatic reset.

Siemens SIRIUS 3RB3 Electronic Overload Relay

The 3RB3026-2QB0 belongs to the Siemens SIRIUS 3RB30 electronic overload relay family, designed for electronic monitoring and protection of three-phase motors.

Its electronic design continuously evaluates motor current and provides a defined Class 20E overload response. The compact S0 contactor-mounted construction allows integration with 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 6–25 A Current Range

The 3RB3026-2QB0 provides an adjustable current-setting range of 6 to 25 A. Siemens' exact product datasheet confirms the 6–25 A range and S0 contactor-mounting configuration.

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 3RB3026-2QB0 is a Class 20E electronic overload relay. Siemens identifies the product under the 3RB30 Class 20E range.

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

Electronic Overload Protection

The primary function of the 3RB3026-2QB0 is electronic motor-overload protection.

The relay continuously monitors 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. Siemens lists these functions as core protection functions of the 3RB30 electronic overload-relay family.

Phase failure and current imbalance can increase motor heating and electrical stress. Electronic monitoring therefore provides broader protection for three-phase motors than overload protection alone.

1 NO + 1 NC Auxiliary Contacts

The Siemens 3RB30 Class 20E range provides 1 normally open (NO) and 1 normally closed (NC) auxiliary contact. These contacts can be used for contactor control, trip indication, PLC feedback, alarms and interlocking.

Typical uses include:

• Contactor-control circuits

• Trip indication

• PLC feedback

• Alarm signalling

• Motor fault monitoring

• Control-system interlocking

Contactor Mounting

The 3RB3026-2QB0 is designed for contactor mounting and belongs to Size S0. Siemens' current product data identifies S0 as both the overload-relay size and the compatible contactor size.

This arrangement allows the relay to form a compact motor-starter assembly with a compatible SIRIUS contactor.

Screw-Terminal Connections

The 3RB3026-2QB0 uses screw-type terminals for both the main current circuit and auxiliary/control circuit. Siemens also specifies a removable auxiliary/control terminal.

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

Manual and Automatic Reset

The exact 3RB3026-2QB0 supports manual and automatic RESET. Siemens specifies both reset modes for this product.

This provides flexibility for motor-control applications where either operator intervention or an appropriately designed automatic reset strategy is required.

TEST Function and Self-Monitoring

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

These functions can support:

• Commissioning

• Functional testing

• Troubleshooting

• Preventive maintenance

• Control-panel servicing

Electrical Characteristics

The exact 3RB3026-2QB0 has an insulation voltage of 690 V and a 6 kV surge-voltage resistance. Siemens specifies approximately 1.2 W total power loss at rated current in the hot operating state, or 0.4 W per pole.

The product is designed for industrial applications and should be installed according to Siemens' specified wiring, protection and environmental requirements.

Compact S0 Design

The 3RB3026-2QB0 is a compact S0-size electronic overload relay suitable for motor starters and industrial control panels.

Its contactor-mounted arrangement helps integrate overload protection directly into a compatible Siemens SIRIUS motor-starter assembly.

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 used for motors with corresponding starting requirements.

Compressors

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

Conveyors

The relay can protect 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 3RB3026-2QB0 is suitable for OEM machine manufacturers, electrical panel builders, automation integrators and industrial maintenance professionals.

Its combination of 6–25 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 3RB3026-2QB0

• Microprocessor-based electronic overload protection

• 6–25 A adjustable current range

• Class 20E

• Size S0

• Contactor mounting

• Screw terminals for main and auxiliary circuits

• Removable auxiliary/control terminal

• Overload protection

• Phase-failure protection

• Asymmetry protection

• 1 NO + 1 NC auxiliary contacts

• Manual RESET

• Automatic RESET

• TEST function

• Self-monitoring

• Switch-position indication

• 690 V insulation voltage

• 6 kV surge-voltage resistance

Benefits

• 6–25 A adjustable range: Suitable for a broad range of medium-current industrial motors.

• 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 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 3RB3026-2QB0?

The Siemens 3RB3026-2QB0 is a compact electronic overload relay for motor protection in the 6–25 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 6–25 A range, Class 20E rating, S0 size, contactor mounting and screw-terminal configuration, 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 3RB3026-2QB0?

It is a Siemens SIRIUS 3RB3 electronic overload relay for motor protection with a 6–25 A adjustable current range and Class 20E characteristic.

2. What is the current setting range?

The adjustable current range is 6–25 A.

3. What is the trip class?

The exact 3RB3026-2QB0 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 3RB3026-2QB0 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 3RB3026-2QB0 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.