What Is an RCCB and How Does It Work?

RCB or Residual Current Breaker are electrical devices that cut the current from the electrical circuit so as to prevent electrocution. The current leakage that it can detect is from 5 mA to 30 mA. Essentially, RCB is utilized in circuits to secure human life from electric shock or electrocution.

A Residual Current Circuit Breaker (RCCB) continuously monitors the current balance between the phase (live) and neutral conductors. Under normal operating conditions, the incoming current equals the return current, and the magnetic fields cancel each other. When a leakage fault occurs—such as insulation damage, moisture ingress, or accidental human contact—a residual current imbalance is created. The internal sensing transformer detects this difference and triggers an ultra fast trip to disconnect power, effectively stopping electric shock and fire risks.

This fast response protection makes RCCBs essential in low voltage distribution systems for residential, commercial, and industrial environments.

CJL1-125 RCCB Product Overview

C&J Electrical proudly presents the CJL1 125 Residual Current Circuit Breaker, a robust and user centric protection device designed for modern electrical safety. Built to meet IEC61008-1 / IEC61008-2 standards, the CJL1 125 combines stable mechanism, premium materials, and enhanced safety features to deliver reliable residual current protection for various applications.

This series supports AC type, A type, and B type tripping characteristics, with multiple rated currents and pole configurations to match global installation requirements. It is widely used for personnel protection against electric shock and equipment protection against earthleakage fire hazards.

Core Functions of CJL1 125 RCCB

• Residual current detection and quick breaking: Detects micro level leakage current and trips within milliseconds to protect lives.
• Overcurrent and earth fault protection: Safeguards circuits and devices from damage caused by leakage and insulation failure.
• Stable long term operation: High electromechanical endurance ensures consistent performance in continuous use.
• Easy installation and standard compatibility: Fits standard 35mm DIN rail and supports PIN busbar for fast wiring.
• Visual identification and marking: Large transparent signboard allows users to add custom labels for circuit management.

Key Product Advantages of CJL1-125

1. Plastic structure operating mechanism delivers more stable and reliable performance than metal structures, with better release force, longer mechanical life, and improved environmental compatibility. It represents a new generation mechanism design.
2. All internal current carrying parts are made of pure copper, ensuring excellent conductivity, low heat generation, and longterm durability.
3. All screws are sealed with plastic covers, preventing unauthorized disassembly and improving overall safety and protection grade.
4. Large transparent signboard supports user defined marking for convenient circuit identification and maintenance.
5. Innovative tripping structure enhances operational safety and breaking reliability under fault conditions.

Technical Data

• Rated current: 16A, 20A, 25A, 32A, 40A, 50A, 63A, 100A, 125A
• Rated voltage: 230V (1P+N), 400V (3P+N)
• Rated frequency: 50/60Hz
• Number of poles: 2P, 4P
• Module size: 36mm
• Circuit type: AC type, A type, B type
• Breaking capacity: 6000A
• Rated residual operating current: 10mA, 30mA, 100mA, 300mA
• Optimum operating temperature: 5°C to 40°C
• Terminal tightening torque: 2.5–4N/m
• Terminal capacity (top/bottom): 25mm²
• Electro mechanical endurance: 4000 cycles
• Mounting: 35mm DIN rail
• Suitable busbar: PIN busbar
• Standard: IEC61008-1 / IEC61008-2

Application Scenarios

The CJL1-125 RCCB provides comprehensive safety protection across many fields:

• Residential buildings: Houses, apartments, kitchens, bathrooms, and outdoor power circuits.
• Commercial spaces: Offices, shops, hotels, schools, and hospitals.
• Industrial sites: Factories, workshops, power distribution boxes, and small machinery.
• Wet & outdoor environments: Construction sites, agricultural facilities, and outdoor lighting systems.
• Renewable & power systems: Small distribution boards, backup power units, and busbar type distribution.

Customization & Supply Support

C&J Electrical provides OEM/ODM brand customization to meet different market and client requirements. The CJL1-125 series offers a full range of specifications for flexible selection. We also supply MCB products and support SKD semi knocked down shipments to optimize logistics and assembly costs.

With high safety performance, stable quality, and wide applicability, CJL1-125 has become a trusted choice for global electrical installers, contractors, and distributors.

Contact Us

If you have any questions about the CJL1-125 Residual Current Circuit Breaker, need product catalogs, pricing, or customized solutions, please feel free to contact C&J Electrical anytime. We provide professional technical support and reliable supply services worldwide.