Product Description

Siemens 3RB3036-2WB0 Electronic Overload Relay – 20–80 A, Class 20E

The Siemens 3RB3036-2WB0 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 20–80 A, a Class 20E overload characteristic, Size S2 construction and contactor mounting. Siemens specifies screw terminals for both the main and auxiliary circuits with manual/automatic reset. The exact article is listed as an active product.

Siemens SIRIUS 3RB3 Electronic Overload Relay

The 3RB3036-2WB0 belongs to the Siemens SIRIUS 3RB30 electronic overload relay family, developed for motor protection in industrial control and automation systems.

Its electronic design continuously evaluates motor current and provides a defined overload response. The relay is designed for S2 contactor mounting, making it suitable for integration into compatible Siemens SIRIUS motor-starter assemblies.

Typical applications include:

• Industrial motor control

• Pumps

• Fans and blowers

• Compressors

• Conveyors

• Production machinery

• Machine tools

• Process equipment

• Industrial automation

• OEM control panels

Adjustable 20–80 A Current Range

The 3RB3036-2WB0 provides an adjustable current-response range of 20 to 80 A. Siemens specifies this exact range for the article.

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

This broad adjustment range makes the relay suitable for a variety of medium-current industrial motor applications.

Class 20E Trip Characteristic

The exact 3RB3036-2WB0 is a Class 20E electronic overload relay. Siemens' Industry Mall identifies the product as 20–80 A, electronic, Size S2, Class 20E, contactor mounting.

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

Electronic Overload Protection

The primary function of the 3RB3036-2WB0 is electronic motor-overload protection.

The relay 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

• Inappropriate starting conditions

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

Phase-Failure and Asymmetry Protection

The Siemens 3RB30 Class 20E range provides overload, phase-failure and asymmetry protection. Siemens identifies these as protection functions of the 3RB30 electronic overload relay family.

Phase failure and current imbalance can cause excessive motor heating. Electronic monitoring therefore provides broader three-phase motor protection than overload protection alone.

1 NO + 1 NC Auxiliary Contacts

The 3RB3036-2WB0 uses the standard 1 NO + 1 NC auxiliary-contact arrangement of the 3RB30 Class 20E range.

These auxiliary contacts can be incorporated into:

• Contactor-control circuits

• Trip indication

• PLC feedback

• Alarm signalling

• Motor fault monitoring

• Control-system interlocking

They provide an interface between the overload relay and the associated motor-control circuit.

Contactor Mounting

The 3RB3036-2WB0 is designed for contactor mounting and is a Size S2 device. Siemens specifies S2 as the overload-relay size and the compatible contactor size.

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

Typical applications include:

• Motor starters

• Industrial control panels

• Automation cabinets

• OEM machinery

• Process-control systems

Screw-Terminal Connections

The 3RB3036-2WB0 uses screw terminals for both the main and auxiliary circuits. Siemens' Industry Mall explicitly identifies the main circuit and auxiliary circuit as screw connections.

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

Manual and Automatic Reset

The exact 3RB3036-2WB0 supports manual and automatic RESET. Siemens explicitly lists both reset modes for the product.

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

TEST Function and Self-Monitoring

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

These features can support:

• Commissioning

• Functional testing

• Troubleshooting

• Preventive maintenance

• Control-panel servicing

Electrical and Thermal Characteristics

The 3RB3036-2WB0 has a 690 V insulation voltage and 6 kV surge-voltage resistance. Siemens documentation specifies approximately 4.6 W total power loss at rated current in the hot operating state.

The specified operating ambient temperature range is -25 °C to +60 °C, with operation up to 2,000 m altitude under the specified conditions.

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

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 protection can help protect compressor motors against excessive operating current.

Conveyors

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

Production Machinery

The S2 design is suitable for medium-current industrial motor-control assemblies.

Process Automation

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

Suitable for OEMs and Panel Builders

The 3RB3036-2WB0 is suitable for OEM machine manufacturers, electrical panel builders, automation integrators and industrial maintenance professionals.

Its combination of 20–80 A adjustable current, Class 20E protection, S2 construction, contactor mounting, screw terminals, phase-failure and asymmetry protection, and manual/automatic reset makes it suitable for industrial motor-protection systems.

Key Features

• Siemens SIRIUS 3RB3 electronic overload relay

• Article number 3RB3036-2WB0

• Microprocessor-based electronic overload protection

• 20–80 A adjustable current range

• Class 20E

• Size S2

• 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

• 690 V insulation voltage

• 6 kV surge-voltage resistance

Benefits

• 20–80 A adjustable range: Suitable for a broad range of industrial motor currents.

• 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 S2 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.

• S2 construction: Suitable for medium-current industrial motor-control applications.

Why Choose Siemens 3RB3036-2WB0?

The Siemens 3RB3036-2WB0 is a compact electronic overload relay for motor protection in the 20–80 A range with a Class 20E characteristic.

Its combination of overload, phase-failure and asymmetry protection, S2 contactor mounting, 1 NO + 1 NC auxiliary contacts, screw terminals and flexible reset options makes it suitable for industrial motor starters, OEM machinery and automation panels.

Siemens currently identifies the exact 3RB3036-2WB0 as an active product, making it suitable for procurement where this specific 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 3RB3036-2WB0?

It is a Siemens SIRIUS 3RB3 electronic overload relay for motor protection with a 20–80 A adjustable current range and Class 20E characteristic.

2. What is the current setting range?

The adjustable current range is 20–80 A.

3. What is the trip class?

The exact 3RB3036-2WB0 is Class 20E.

4. Does it provide phase-failure protection?

Yes. The Siemens 3RB30 Class 20E 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 3RB3036-2WB0 is designed for S2 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. Does it have diagnostic functions?

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

10. Where can I buy Siemens 3RB3036-2WB0 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.