OEM/ODM Earth Leakage Circuit Breaker Supplier

Are you in need of high-quality and durable Earth Leakage Circuit Breakers? CDADA offers comprehensive OEM customization solutions. As a reliable manufacturer with our own factory, we provide a 3-year warranty on our products.

What Is an Earth Leakage Circuit Breaker (CBR)?

An Earth Leakage Circuit Breaker (CBR), also known as Earth Leakage Circuit Breaker with Integral Overcurrent Protection (CBR) per IEC 60947-2 Annex B, is a sophisticated low-voltage protection device that combines residual current (earth leakage) protection with overload and short-circuit protection in a single molded case unit. Operating at rated voltages up to 415V AC (50/60Hz) with current ratings from 16A to 800A, CBRs serve as comprehensive protection devices for industrial, commercial, and critical infrastructure applications .

Unlike standalone Residual Current Circuit Breakers (RCCBs) that provide only earth leakage protection, CBRs integrate:

Thermal-magnetic or electronic overcurrent protection (L-S-I curves)

Residual current detection (10mA to 1000mA sensitivity)

Short-circuit breaking capacity up to 85kA

This integration eliminates the need for separate MCB/RCCB combinations, reducing installation space and improving coordination reliability .

Product Categories & Configurations

Classification	Type	Current Range	Key Characteristics
Residual Current Type	Type AC	16A – 800A	Detects sinusoidal AC residual currents only, general-purpose applications
Residual Current Type	Type A	16A – 800A	Detects AC + pulsating DC (rectified AC), modern electronic loads
Sensitivity (IΔn)	High Sensitivity	10mA – 30mA	Personnel protection, medical locations, wet areas
	Medium Sensitivity	100mA – 300mA	Fire protection, general industrial
	Low Sensitivity	500mA – 1000mA	Fire prevention in high-leakage installations, selective protection
Time Delay	Instantaneous	All ratings	General-purpose, <40ms at 5×IΔn
Time Delay	Selective (S-Type)	100mA – 1000mA	Delayed tripping (130-500ms at 1×IΔn), upstream discrimination
Pole Configuration	4-Pole	16A – 800A	Three-phase + neutral, adjustable neutral protection (50-100%)
Mounting	Fixed	16A – 800A	Direct busbar connection, cost-effective

Breaking Capacity Grades:

Standard (N): 25kA – 36kA (Distribution networks)

High (S): 50kA – 70kA (Industrial mains)

Ultra-High (H): 85kA (Power infrastructure)

Core Functions & Protection Capabilities

Integrated Protection Functions

Function	Detection Principle	Technical Parameters
Overload Protection (L)	Bimetallic thermal expansion or electronic RMS sensing	0.8 – 1.0 × In setting, inverse time curve, ±10% accuracy
Short-Circuit Delay (S)	Electronic timing or magnetic delay	2-10 × In, 0.1s – 0.5s delay, selective coordination
Instantaneous Trip (I)	Magnetic solenoid or electronic instantaneous	5-20 × In, <20ms operation, current limiting
Earth Leakage (G/Δ)	Core Balance Current Transformer (CBCT)	10mA – 1000mA IΔn, ±10% sensitivity accuracy
Ground Fault (GF)	Vector sum current sensing	20-100% of In, 0.1s-1.0s delay, core-balance method
Self-Monitoring	Internal circuit integrity check	Continuous CBCT and trip coil monitoring, fault alarm output

Residual Current Detection Technology

The Core Balance Current Transformer (CBCT) or Toroidal Transformer forms the heart of earth leakage protection:

Normal Operation: All live conductors (phase + neutral) pass through the toroidal core. Balanced currents generate opposing magnetic fields that cancel to zero net flux—no secondary current induced .

Fault Condition: When leakage current flows to earth (through insulation failure or human contact), the current imbalance creates residual magnetic flux in the toroidal core. This flux induces voltage in the secondary winding, energizing a sensitive relay or electronic trip circuit .

Trip Characteristics per IEC 61008/61009:

1 × IΔn: Trip ≤ 300ms (instantaneous), ≤ 500ms (selective S-type)

2 × IΔn: Trip ≤ 150ms (instantaneous), ≤ 200ms (S-type)

5 × IΔn: Trip ≤ 40ms (instantaneous), ≤ 150ms (S-type)

Application Environments & Use Cases

Industry Sector	Specific Application	Typical Specifications
Data Centers	Main distribution, UPS bypass, bus-coupler protection	250A-500A, Type A, 300mA S-type selective, 70kA Icu, communication-enabled
Healthcare Facilities	Hospital main distribution, medical IT systems, operating theaters	100A-400A, Type A, 10mA/30mA high sensitivity, isolation monitoring
Manufacturing Plants	Motor control centers, welding equipment, variable speed drives	160A-500A, Type B (for VFDs), 300mA, 50kA Icu, electronic trip
Commercial Buildings	High-rise distribution, shopping malls, airports	125A-400A, Type A, 100mA/300mA, 36kA Icu
Oil & Gas / Marine	Offshore platforms, drilling rigs, ship power systems	250A-500A, Type A, 500mA, tropicalized (T2), corrosion-resistant

Manufacturing Process & Production Workflow

Precision Manufacturing Sequence

Raw Material IQC → Toroidal Transformer Production → Moulded Case Fabrication → Contact System Assembly → Electronic Trip Unit Integration → Residual Current Module Calibration → Primary Assembly → Comprehensive Testing → Final QC → Packaging

Critical Manufacturing Stages

Stage	Process Details	Quality Control Points
Toroidal Transformer Winding	High-permeability nanocrystalline or ferrite core (µr > 10,000), precision winding of primary (through-pass) and secondary (sensing) windings, vacuum impregnation	Core magnetization curve verification, secondary voltage at 1×IΔn ±5%, insulation resistance >100MΩ
CBCT Integration	Mounting of toroidal core around all phase/neutral conductors, shielding against external magnetic fields, connection to trip relay/electronics	Balance test with 6×In load (no nuisance trip), immunity to 3rd harmonics
Residual Current Trip Mechanism	Sensitive polarized relay (5-50mW trip power) or electronic MOSFET trigger, mechanical coupling to main trip bar	Trip power verification, response time <20ms, temperature stability -25°C to +70°C
Moulded Case Production	BMC thermosetting plastic (DMC-2) injection molding, 150-180°C cure, high tracking resistance >600V	Dimensional tolerance ±0.1mm, dielectric strength >15kV/mm, flame retardant UL 94 V-0
Main Contact Assembly	Silver-plated copper (AgNi 90/10) contacts, CNC-machined arms, brazing in nitrogen atmosphere	Contact resistance <50μΩ, silver thickness 8-12μm (XRF), hardness HV 100-150
Electronic Trip Unit Programming	Microprocessor-based LSIG+Δ protection, firmware upload, curve calibration, communication protocol setup	±5% current accuracy, ±10% time accuracy, ZSI (Zone Selective Interlocking) verification
Final Integration & Calibration	Assembly of thermal-magnetic or electronic trip system with residual current module, mechanical interlocking, handle mechanism	Combined overcurrent + earth leakage trip verification, dielectric withstand 3kV/1min

Primary Raw Materials & Component Specifications

Component	Material Specification	Supplier Standards	Key Properties
Toroidal Core (CBCT)	Nanocrystalline alloy (Finemet) or Mn-Zn ferrite (PC40)	IEC 60404-8, JIS C 2531	High permeability µr > 10,000, low coercivity <2A/m, saturation flux density >1.2T
Sensing Coil Wire	Enameled copper wire (0.05-0.1mm), Class F 155°C	IEC 60317	Breakdown voltage >1kV, flexibility >10× diameter, solderability 390°C
Trip Relay	Polarized latching relay, sensitivity 5-50mW	IEC 61810	Response time <10ms, coil resistance 1-5kΩ, mechanical life >10⁶ operations
Moulded Case Housing	BMC (Bulk Molding Compound) DMC-2, glass fiber reinforced	IEC 60664-1, UL 94 V-0	Tracking index >600V, heat resistance 180°C, impact strength >8 kJ/m²
Main Contacts	Electrolytic copper (Cu-ETP) + Silver-nickel plating (AgNi 90/10)	ASTM B152	Conductivity ≥100% IACS, arc erosion resistance, anti-welding properties
Bimetallic Elements	Inconel/passivated steel composite (ASTM TM2)	ASTM B388	Deflection rate 0.15-0.25mm/°C, long-term stability ±3%, creep resistance
Electronic Components	Industrial-grade PCBs, Hall-effect sensors, ARM Cortex-M4 processors	IEC 60721-3-3, IEC 61000	Operating temperature -25°C to +70°C, EMC immunity Level 4, SIL 2 capable
Terminals	T2 copper (C11000) with tin plating (8-12μm)	ASTM B187/B16	Current density 1.2-1.5 A/mm², torque withstand 5-15Nm, corrosion resistance
Operating Mechanism	Spring steel (SWOSC-V) or stainless steel (301)	JIS G 3560	Fatigue life >20,000 cycles, tensile strength 1800-2000MPa, relaxation <5%

Standards Compliance & Testing Protocols

International Standards Framework

Standard	Scope	Applicable Ratings
IEC 60947-2 Annex B	Circuit-breakers incorporating residual current protection (CBR)	Industrial CBRs >80A, comprehensive protection
EN 60947-2	European harmonized version of IEC 60947-2	CE marking, EU market compliance
GB/T 14048.2	Chinese national standard equivalent	CCC certification, China market

Mandatory Type Tests (IEC 60947-2 + Annex B)

Test Category	Specific Test	Acceptance Criteria
Residual Current Performance	Tripping time at 1×IΔn, 2×IΔn, 5×IΔn	≤300ms, ≤150ms, ≤40ms (instantaneous); S-type: ≤500ms, ≤200ms, ≤150ms
	Non-tripping at 0.5×IΔn	No trip for 2× rated delay time
	Surge current withstand (8/20μs, 3kA)	No nuisance trip, Type A: 250A impulse, Type F: 1000A, Type B: 3000A
Overcurrent Protection	Temperature rise at rated In	Terminals ≤80K, case ≤40K
	Short-circuit breaking (Icu/Ics)	3 operations, successful interruption, dielectric recovery
	Trip curve verification (L-S-I)	±10% current accuracy, ±20% time accuracy
Dielectric Properties	Power-frequency withstand (2.5kV-3.5kV/1min)	No breakdown, no flashover
Dielectric Properties	Impulse withstand (8kV 1.2/50μs)	No disruptive discharge
Mechanical & Environmental	Mechanical endurance (10,000-20,000 cycles)	<5% parameter drift, no failure
Mechanical & Environmental	EMC immunity (IEC 61000-4 series)	No nuisance tripping from radiated/conducted interference

Factory Quality Control & Inspection Standards

Incoming Material QC (IQC)

Material	Inspection Items	Sampling Plan	Equipment
Toroidal cores	Magnetic permeability, saturation flux, core losses	Per batch, B-H curve testing	B-H analyzer, impedance analyzer
Sensing wire	Diameter, insulation thickness, breakdown voltage	AQL 0.65	Micrometer, dielectric tester
BMC plastic compound	Glass content, viscosity, cure characteristics, tracking index	Per batch, COA + testing	Rheometer, DSC analyzer, tracking test apparatus
Silver plating solution	Metal concentration, pH, impurities	Daily monitoring	Atomic absorption spectrometer
Electronic components	Function test, parameter verification, firmware version	100% AOI, 5% functional	LCR meter, oscilloscope, boundary scan

In-Process Quality Control (IPQC)

Station	Control Parameters	Frequency	Method
Toroidal transformer winding	Turns ratio, inductance, insulation resistance	Every unit	LCR meter, insulation tester
CBCT assembly	Balance test with rated load, immunity to harmonics	Every 100 units	Primary injection test, harmonic generator
Residual current calibration	Trip threshold at IΔn, response time, non-trip at 0.5×IΔn	Every unit	Automated RCD tester (0.5-1000mA programmable)
Main contact assembly	Contact gap, pressure, alignment, resistance	Every 100 units	Force gauge, micro-ohmmeter
Final integration	Combined overcurrent + earth leakage trip verification	Every unit	Integrated test bench (primary injection + leakage simulation)

Final Quality Control (FQC) & Outgoing QC (OQC)

Test Item	Standard	Sample Size
Residual current trip time	1×IΔn, 2×IΔn, 5×IΔn per IEC 61008/61009	100%
Non-trip test at 0.5×IΔn	2× rated delay time	100%
Overcurrent trip curve	1.05×In, 1.25×In, 5×In, 10×In	100%
Dielectric withstand voltage	2.5kV AC/1min	100%
Insulation resistance	>100MΩ @ 500V DC	100%
Contact resistance	<50μΩ per pole	100%
Torque marking verification	Terminal tightening per specification	100%
Visual & dimensional inspection	Zero defects on critical dimensions	100%
Marking permanence	Solvent wiping, abrasion test	AQL 1.0
Packaging integrity	Drop test, vibration (ISTA 3A)	Per lot

Production Infrastructure & Manufacturing Capability

Advanced Production Equipment

Equipment Category	Machine Specification	Function	Capacity
Toroidal Winding Machines	Automated toroidal winding with tension control	CBCT primary/secondary winding, precision layering	5,000 transformers/day
Core Annealing Furnace	Vacuum annealing with nitrogen atmosphere	Nanocrystalline core heat treatment, stress relief	2,000 cores/batch
Injection Molding	300-ton BMC thermosetting press	CBR housing, arc chute, terminal blocks	3,000 cases/day
CNC Machining	5-axis vertical machining center	Precision contact machining, complex geometries	8,000 contact sets/month
Surface Treatment	Automated silver plating line	Contact plating 8-12μm, thickness uniformity ±1μm	4,000 kg/day
Assembly	Labor assembly cells	Mechanism assembly, CBCT integration, calibration	1,500 units/day per line
Testing Equipment	Integrated CBR test bench	Combined overcurrent + residual current verification	300 units/hour
	EMC test chamber (3m/10m, Teseq)	Immunity/emission testing for electronic units	50 units/day

Production Capacity & Lead Times

Product Category	Monthly Capacity	Standard Lead Time	Urgent Order Capability
CBR 4P (16A-125A)	10,000 units	4-5 weeks	3 days (stock components)
CBR Industrial (160A-400A)	8,000 units	4-5 weeks	5 days
CBR Heavy Industrial (630A-800A)	3,000 units	4-5 weeks	7 days
Custom configurations (special IΔn, curves)	Project basis	5-6 weeks	2 weeks

Engineering & Technical Team Structure

Department	Personnel	Expertise	Responsibilities
R&D Engineering	5 engineers	Residual current technology, magnetic sensor design, embedded systems, power electronics	New CBR development, Type B/F/B+ innovation, patent portfolio (40+ patents)
Process Engineering	18 engineers	Toroidal transformer manufacturing, BMC molding, precision assembly, lean manufacturing	Production optimization, SOP documentation, yield improvement (>99.5%)
Testing & Validation	15 engineers	High-current testing, residual current simulation, EMC, environmental testing	Type testing coordination (IEC 60947-2 Annex B, IEC 61008/61009), failure analysis
Application Engineering	10 engineers	Selective coordination, earth leakage protection schemes, EV/renewable applications	Customer technical support, discrimination studies, site commissioning
Quality Assurance	30 technicians	ISO 9001, ISO 14001, statistical process control, metrology laboratory	Supplier audit, process audit, corrective action, calibration management

Certifications & Compliance Documentation

Certification	Issuing Body	Scope	Validity
ISO 9001:2015	ZHONGDA HUAYUAN	Quality management system	Annual surveillance
IEC 60947-2 Annex B Type Test	Intertek	CBR industrial performance	Per product series
CE Marking	Notified Body	EU market access	Design-dependent
CCC (China)	CQC	Chinese compulsory certification	5-year validity
CB Scheme	IECEE	International certification	Per product series

Why Our CBR Manufacturing Stands Apart

Our production facility represents 40 years of specialization in residual current and earth leakage protection technology, delivering CBRs that exceed global standards through:

Toroidal transformer expertise: In-house nanocrystalline core production, precision winding automation, and comprehensive CBCT testing ensuring <±5% sensitivity accuracy

Vertical integration: From core material processing to final assembly, complete control over critical components (toroidal transformers, electronic trip units, molded cases)

Advanced testing infrastructure: $3M+ invested in integrated CBR test systems capable of simultaneous overcurrent and residual current verification, Type B DC sensitivity testing, and EMC compliance

Global certification strategy: Multi-standard compliance enabling seamless market entry across 100+ countries without redundant testing

For technical specifications, selective coordination studies, Type B application guidance, or factory audit scheduling, our engineering team provides direct consultation to ensure your earth leakage protection architecture meets both personnel safety requirements and operational continuity objectives.

CDADA is a Earth Leakage Circuit Breaker manufacturer and supplier in China. Our factory serves diverse industries such as power systems, building automation, and industrial manufacturing, offering flexible OEM/ODM solutions.

News Recommendations