Engineered to meet rigorous international standards (IEC/EN 61009-1, CE, UL). Discover our featured flagship low-voltage protection units.
In modern low-voltage distribution systems, electrical safety and operational continuity represent the dual pillars of engineering excellence. For decades, traditional switchboard architecture relied on split arrangements combining a standard Miniature Circuit Breaker (MCB) for thermal-magnetic overload/short-circuit protection and a Residual Current Device (RCD/RCCB) for earth leakage protection. However, as electrical loads become increasingly complex—fueled by power electronics, variable frequency drives (VFDs), solar photovoltaic (PV) inverters, and EV charging stations—the legacy approach reveals critical vulnerabilities: space inefficiency, nuisance tripping, complex wiring, and lack of selective fault isolation.
Wenzhou OFA Electrical Technology Co., Ltd. (operating under proprietary brand OFA) has pioneered the development of next-generation Residual Current Operated Circuit Breakers with Overcurrent Protection (RCBO). Founded in 2013 and headquartered in Yueqing, Wenzhou—widely acclaimed as the Electrical Capital of China—OFA integrates advanced electromagnetic physics, precision micro-mechanisms, and automated calibration technology to deliver single-unit, dual-function protection across commercial, industrial, and residential infrastructure.
Integrates thermal overload, magnetic short-circuit, and zero-sequence toroidal earth leakage detection into a single compact DIN-rail module, eliminating the need for separate MCB + RCCB setups.
Prevents widespread power outages. When an earth leakage fault occurs on a specific sub-circuit, only the affected RCBO trips, maintaining uninterruptible power to adjacent critical loads.
Compact 1P+N (18mm width) design frees up to 50% cabinet footprint in main distribution boards (MDBs) and final distribution boards (DBs), drastically reducing switchgear enclosure costs.
For international procurement directors, panel builders, and EPC contractors, selecting the correct RCBO series requires precise alignment between electrical grid characteristics and breaker tripping dynamics. OFA manufactures RCBO devices designed in strict accordance with IEC/EN 61009-1 and GB/T 16917.1, addressing diverse environmental and electrical demands.
With modern loads introducing smooth DC residual currents and high-frequency harmonics, matching the residual current tripping waveform characteristics is vital to prevent protection blindness:
| Waveform Type | Detectable Residual Currents | Typical Application Environments | OFA Recommended Model Series |
|---|---|---|---|
| Type AC | Sinusoidal Alternating Currents (50/60Hz) | Standard resistive loads, tungsten lighting, basic heating circuits | OFR1 Series, OFC Series |
| Type A | Sinusoidal AC + Pulsating Direct Currents with DC superposition up to 6mA | Single-phase inverters, IT equipment, washing machines, modern LED drivers | OFMIN Series, OFOM Series |
| Type B / Type F | AC + Pulsating DC + Smooth DC currents up to 1000Hz | Three-phase EV fast chargers, solar PV inverters, variable frequency drives, medical equipment | OFKL-80A Series, Customized Smart RCBOs |
OFA RCBOs offer dual protection mechanisms: thermal bimetallic strips for inverse time-delay overload tripping, and electromagnetic armatures for instantaneous short-circuit protection. We supply short-circuit breaking capacity ratings of 6,000A (6kA) and 10,000A (10kA) under IEC 61009-1 testing protocols.
In today's volatile global supply chain landscape, global procurement teams require partners who deliver not only competitive cost structures but also unwavering delivery punctuality and rigorous quality consistency. Operating from Yueqing, Wenzhou—the industrial epicenter of Asia’s low-voltage electrical component cluster—Wenzhou OFA Electrical Technology Co., Ltd. integrates digital manufacturing, full-traceability automated testing, and agile supply chain logistics.
Direct proximity to raw material refining, silver-alloy contact stamping, precision mold injection, and arc-chute stamping reduces component lead times to ultra-short windows while minimizing transport overheads.
Every single RCBO unit undergoes automated type testing: 100% verification of instantaneous trip current, residual current trip time response (at 1IΔn, 2IΔn, 5IΔn), dielectric insulation withstand voltage, and mechanical life cycling.
Recognized by Chinese financial and industrial authorities for seamless legal compliance, honest operations, financial stability, and long-term client contract fulfillment.
From micro-circuit residual current protection to high-capacity industrial air circuit breakers, OFA manufactures complete low-voltage power automation assemblies.
Primary protection up to 1250A. Make, carry, and break currents under normal conditions, with precision electronic/thermal-magnetic tripping under overload and short-circuit faults.
Terminal distribution guardians featuring high breaking capacity in standard DIN-rail modular widths. Designed for high reliability in commercial panels and residential DBs.
High-capacity main incoming breakers with intelligent microprocessor controller, flexible communication protocols (Modbus-RTU), and deep diagnostic intelligence.
Dedicated high-sensitivity earth leakage protection units without integral overcurrent release. Graded protection against indirect contact electric shocks and fire hazards.
All-in-one flagship protection combining overload, short-circuit, and high-sensitivity earth leakage tripping in single-module and multi-pole footprints.
Heavy-duty disconnection switches ensuring visible circuit isolation and safe physical air gaps during maintenance and routine inspection operations.
OFA electrical hardware operates seamlessly across harsh environmental conditions, critical energy infrastructure, and high-density commercial sites.
OFA RCBOs ensure selective tripping in high-density office towers and shopping centers, isolating localized electrical faults without causing total floor blackouts.
Specially engineered DC Molded Case Circuit Breakers (OFID Series) and Type A/B RCBOs prevent DC earth leakage hazards and protect inverter input/output circuits.
Prevents blinding of residual current protection caused by smooth DC leakage in electric vehicle onboard chargers, fulfilling IEC 62955 safety mandates.
Provides high breaking capacity (10kA) and fast arc interruption, protecting sensitive server racks and dual-UPS distribution units against transient short circuits.
Vibration-resistant terminal clamps and high thermal stability withstand harsh factory conditions, motor start-up surges, and continuous load harmonics.
Ergonomic aesthetic designs with clear visual trip indicators (Red/Green state window) providing homeowner peace of mind and simplified maintenance troubleshooting.
Discover how OFA partners across Europe, Asia-Pacific, and Latin America optimize electrical distribution reliability.
We deliver transparent project roadmaps whether you require off-the-shelf standardized breakers or fully customized OEM/ODM electrical assemblies.
Core Needs: Rapid implementation, proven product stock, ROI clarity, and simple maintenance.
Core Needs: High redundancy design, custom branding/laser etching, bespoke terminal pinouts, and specialized tripping curves.
Detailed answers to technical, operational, and commercial questions from enterprise buyers and electrical engineers.
Complete your power distribution architecture with our full suite of certified circuit protection devices.
OFA Electrical
