NB3LEU-A-B20 Chint RCBO 20A B Curve 30mA 10kA 1 Pole + Neutral

Why Choose the Chint NB3LEU-B20 RCBO?

The Chint NB3LEU-B20 is a compact and reliable residual current operated circuit breaker with over-current protection (RCBO) designed for residential, commercial and light industrial electrical installations. As part of the Chint NB3LEU series, it combines earth leakage protection, overload protection and short-circuit protection in one modular device.

This RCBO features a 1P+N configuration, making it suitable for single-phase circuits requiring both live and neutral switching. Its B curve tripping characteristic is ideal for circuits with low inrush currents, while the 30 mA residual current sensitivity provides additional protection against electric shock.

With a rated current of 20 A, a rated voltage of 240 V AC and a short-circuit breaking capacity of 10 kA, the NB3LEU-B20 is well suited to socket outlets, radial circuits and general-purpose final circuits. Its DIN rail mounting design supports quick and secure installation in consumer units and distribution boards.

Key Advantages

• Compact RCBO combining RCD and MCB protection.
• 20 A rated current for general-purpose final circuits.
• 30 mA residual current sensitivity for additional personal protection.
• B curve characteristic suitable for circuits with low inrush current.
• 10 kA short-circuit breaking capacity for dependable fault protection.
• DIN rail mounting for fast installation in consumer units and distribution boards.

Key Features

• Chint NB3LEU series electronic RCBO.
• 20 A rated current.
• 30 mA residual operating current.
• 1P+N configuration.
• B curve over-current protection.
• 10 kA rated short-circuit capacity.
• Provides overload, short-circuit and earth leakage protection.
• DIN rail mounting for modular electrical assemblies.

Technical Specifications

• Manufacturer: Chint
• Series: NB3LEU
• Model: NB3LEU-B20
• Product type: Residual current operated circuit breaker with over-current protection / RCBO
• Number of poles: 1P+N
• Rated current: 20 A
• Residual operating current: 30 mA
• Residual current type: Type AC
• Tripping curve: B curve
• Rated voltage: 230 / 240 V AC
• Rated frequency: 50 / 60 Hz
• Rated short-circuit capacity: 10 kA
• Rated insulation voltage: 500 V
• Rated impulse withstand voltage: 4 kV
• Mounting type: 35 mm DIN rail
• Protection rating: IP20
• Operating temperature: approx. -5 to +40°C
• Standards: IEC / EN 61009-1

Combined Circuit and Earth Leakage Protection

RCBOs such as the Chint NB3LEU-B20 combine the functions of an MCB and an RCD in a single device. This allows the circuit to be disconnected in the event of overload, short circuit or earth leakage, helping improve electrical safety and circuit reliability.

The NB3LEU-B20 is suitable for applications where individual circuit protection is required. By protecting each final circuit independently, RCBOs can help minimise disruption compared with shared RCD arrangements, as a fault on one circuit is less likely to disconnect unrelated circuits.

Typical Applications

• Consumer units and distribution boards.
• Socket outlet circuits.
• Residential electrical installations.
• Commercial building circuits.
• General-purpose radial circuits.
• Electrical panels requiring combined over-current and residual current protection.

Trusted by Electrical Installers Worldwide

Chint RCBOs are widely used by electrical contractors, panel builders and maintenance engineers to deliver reliable circuit protection in residential, commercial and light industrial electrical installations.