Product Description

Siemens 3RB3026-2PB0 Electronic Overload Relay – 1–4 A, Class 20E

The Siemens 3RB3026-2PB0 is a microprocessor-based electronic overload relay from the Siemens SIRIUS 3RB3 series, designed for reliable protection of motors against overload, phase failure and asymmetry. The exact Siemens product data specifies an adjustable current range of 1 to 4 A, Class 20E, Size S0, contactor mounting, screw terminals for the main and auxiliary circuits, and manual/automatic reset. Siemens currently lists this article as an active product.

Siemens SIRIUS 3RB3 Electronic Overload Relay

The 3RB3026-2PB0 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 continuously evaluates motor current and provides a defined Class 20E overload response. The compact S0 contactor-mounted construction makes it suitable for integration into compatible Siemens SIRIUS motor-starter assemblies.

Typical applications include:

• Industrial motor control

• Small pumps

• Fans and blowers

• Small compressors

• Conveyors

• Machine tools

• Production machinery

• Process equipment

• Industrial automation

• OEM control panels

Adjustable 1–4 A Current Range

The 3RB3026-2PB0 provides an adjustable current-response range of 1 to 4 A, with a 4 A thermal current. Siemens specifies the exact 1–4 A range and 4 A rated operational current for this article.

This makes the relay suitable for protecting motors with relatively low rated currents.

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

Class 20E Trip Characteristic

The exact 3RB3026-2PB0 is a Class 20E electronic overload relay. Siemens identifies this article under the 3RB30 Class 20E range.

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

Electronic Overload Protection

The primary function of the 3RB3026-2PB0 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

• Excessive starting duration

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

Phase-Failure and Asymmetry Protection

The Siemens 3RB30 Class 20E range provides overload, phase-failure and asymmetry protection.

These functions are particularly important for three-phase motors because phase loss or current imbalance can increase motor heating and electrical stress.

The relay therefore offers broader motor protection than overload protection alone.

1 NO + 1 NC Auxiliary Contacts

The 3RB3026-2PB0 provides 1 normally open (NO) and 1 normally closed (NC) auxiliary contact.

Siemens specifies the NC contact for contactor disconnection and the NO contact for the “tripped” message.

These auxiliary contacts can be incorporated into:

• Contactor-control circuits

• Trip indication

• PLC feedback

• Alarm signalling

• Motor fault monitoring

• Control-system interlocking

Contactor Mounting

The 3RB3026-2PB0 is designed for contactor mounting and belongs to Size S0. Siemens specifies the associated contactor size as S0, with approximate dimensions of 87 mm height, 45 mm width and 84 mm depth.

This allows the overload relay to be integrated into a compact motor-starter assembly with a compatible Siemens SIRIUS contactor.

Screw-Terminal Connections

The 3RB3026-2PB0 uses screw-type terminals for both the main current circuit and auxiliary/control circuit. The auxiliary and control terminal is removable.

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

Manual and Automatic Reset

The exact 3RB3026-2PB0 supports manual and automatic RESET. Siemens also specifies a typical recovery time of approximately 3 minutes after an overload trip with automatic reset, while manual and remote-reset recovery can be immediate under the specified conditions.

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

TEST Function and Self-Monitoring

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

These functions can support:

• Commissioning

• Functional testing

• Troubleshooting

• Preventive maintenance

• Control-panel servicing

Electrical Characteristics

The 3RB3026-2PB0 has a 690 V rated operational voltage, 690 V insulation voltage and 6 kV surge-voltage resistance. Siemens specifies approximately 0.1 W total power loss at rated current in the hot operating state, or about 0.03 W per pole.

The relay is specified for 50–60 Hz operation and an ambient operating temperature of -25 °C to +60 °C. Installation altitude is specified up to 2,000 m under the applicable conditions.

Motor Power Applications

For three-phase motors, Siemens specifies guide values of approximately 0.37–1.5 kW at 400 V, 50 Hz, depending on the actual motor characteristics. At 500 V the listed guide range is 0.37–2.2 kW, and at 690 V it is 0.55–3 kW. The actual motor starting and rated data must always be considered when selecting the relay.

Industrial Motor-Control Applications

Small Pumps

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

Fans and Blowers

The Class 20E characteristic can be used where the motor has corresponding starting requirements.

Small Compressors

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

Conveyors

The relay can protect compatible low-current conveyor motors against excessive mechanical loading and abnormal phase conditions.

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 3RB3026-2PB0 is suitable for OEM machine manufacturers, electrical panel builders, automation integrators and industrial maintenance professionals.

Its combination of 1–4 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 3RB3026-2PB0

• Microprocessor-based electronic overload protection

• 1–4 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

• 1–4 A adjustable range: Suitable for low-current industrial motor applications.

• 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 motor-control-panel space.

Why Choose Siemens 3RB3026-2PB0?

The Siemens 3RB3026-2PB0 is a compact electronic overload relay designed for motor protection in the 1–4 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 small industrial motor starters, OEM machinery and automation panels. Siemens' current Industry Mall data identifies the article as an active SIRIUS 3RB product.

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 3RB3026-2PB0?

It is a Siemens SIRIUS 3RB3 electronic overload relay for motor protection with a 1–4 A adjustable current range and Class 20E characteristic.

2. What is the current setting range?

The adjustable current range is 1–4 A.

3. What is the trip class?

The exact 3RB3026-2PB0 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. The NC contact is specified for contactor disconnection and the NO contact for the “tripped” indication.

6. Is it contactor-mounted?

Yes. The 3RB3026-2PB0 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. The 3RB30 Class 20E range provides TEST functionality, switch-position indication and self-monitoring.

10. Where can I buy Siemens 3RB3026-2PB0 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.