Explore our top-tier OEM miniature, molded case, and residual current circuit breakers designed for global power distribution systems.
Understanding the transition from traditional mechanical distribution towards smart, resilient, and DC-native protection infrastructure.
The global low-voltage electrical distribution market is undergoing a seismic paradigm shift driven by decarbonization, electrification of transport, and the rapid deployment of distributed renewable energy storage. According to industry intelligence, the demand for high-reliability current circuit breakers—including Miniature Circuit Breakers (MCB), Molded Case Circuit Breakers (MCCB), Air Circuit Breakers (ACB), Residual Current Circuit Breakers (RCCB), and RCBO units—is accelerating at an unprecedented CAGR.
Modern electrical networks no longer handle pure sinusoidal AC currents. The proliferation of non-linear loads, switch-mode power supplies, variable frequency drives (VFDs), and solar photovoltaic (PV) inverters introduces complex harmonic distortions and high-frequency residual currents. OEM factories must innovate beyond legacy IEC 60898-1 baselines to engineer electromagnetic structures capable of managing high DC components, Type B residual leakage detection, and extreme short-circuit breaking capacities ($I_{cu}$) reaching up to 100kA.
Driving continuous progress in power distribution and switchgear control technology with rigorous ISO9001 quality management.
Founded in 2013, Wenzhou OFA Electrical Technology Co., Ltd. is rooted in Yueqing, Wenzhou—the heart of China's low-voltage electrical industry cluster. The company owns independent brands such as "OFA", with products covering power systems, renewable energy, industrial automation, commercial construction, and equipment manufacturing.
Over more than a decade of steady growth, OFA has established a solid reputation as a down-to-earth, responsible electrical manufacturer. Adhering to honest, law-abiding operations, we have earned a Tax Credit Grade A rating for seven consecutive years, retaining deep long-term partnerships across more than 50 countries worldwide.
We are committed to enabling power distribution architectures to operate safer and smarter through engineered products integrating industry best practices, independent R&D, and strict zero-defect quality control.
Our technical team continues to delve deep into R&D improvements. Equipped with full-process type testing and factory inspection devices, we perform rigorous verification of mechanical endurance, thermal temperature rise, dielectric breakdown, and insulation performance.
Through flexible manufacturing combining modular standardization and bespoke OEM/ODM adaptation, we precisely match client specifications, providing optimized cost-to-performance ratios and rapid time-to-market.
We utilize automated assembly lines and digital vision inspection stations. Every step from stamped silver contact rivets to magnetic trip coils undergoes strict in-process quality control (IPQC), minimizing out-of-factory defect rates.
From initial single-line diagram (SLD) reviews to international compliance logistics and site commissioning support, OFA delivers complete technical governance across the product lifecycle.
Comprehensive multi-scenario circuit breakers engineered for safety, intelligence, and thermal efficiency.
Primary function: Make, carry, and break normal circuit currents, and interrupt specified abnormal fault currents (overload and short-circuit) in heavier industrial feeders.
The standard protective safeguard at the tail end of modern low-voltage distribution networks. Guarantees space-saving, precise tripping against micro-overloads.
High-capacity core protection devices designed for main incoming low-voltage switchboards, power plant auxiliaries, and data center mains.
Specialized high-reliability earth-leakage devices designed to prevent lethal electrocution and electrically induced fires.
Innovatively integrates three core functions—overload, short-circuit, and high-sensitivity earth leakage—into a compact single DIN-rail module.
Combines the main disconnecting capability of an Isolator with heavy mechanical endurance for safe maintenance isolation.
| Category | Standard Rated Current ($I_n$) | Breaking Capacity ($I_{cu}$) | Protection Scope | Typical Application Scenario |
|---|---|---|---|---|
| MCB (Miniature) | 1A – 125A | 4.5kA – 15kA | Overload, Short Circuit | Residential, Commercial Sub-distribution, Lighting Circuits |
| MCCB (Molded Case) | 16A – 1600A | 25kA – 100kA | Overload, Short Circuit, Under-voltage | Industrial Main Feeder Panels, Motor Circuits, Solar Inverters |
| ACB (Air Breaker) | 630A – 6300A | 50kA – 120kA | Selective Overload, Short Circuit, Ground Fault | Transformer Main LV Side, Heavy Plant Distribution, Data Centers |
| RCCB (Residual Current) | 16A – 100A | Up to 10kA (with fuse) | Earth Leakage, Electric Shock Protection | Wet Environments, Damp Industrial Lines, Domestic Safety |
| RCBO (Combined) | 6A – 63A | 6kA – 10kA | Overload, Short Circuit, Earth Leakage | Critical Individual Branch Protection, EV Chargers, IT Panels |
| DC MCCB / MCB | 10A – 800A | 10kA – 50kA (up to 1500VDC) | DC Overcurrent, Reverse Current Faults | Solar PV Combiner Boxes, BESS Battery Racks, DC Microgrids |
Engineered to excel in demanding environments—from distributed solar plants to high-density data infrastructure.
DC Molded Case Circuit Breakers (BLTM3DC and OFBLT series) optimized for high DC working voltages up to 1500VDC, protecting string inverters and battery energy storage systems (BESS).
Type A & Type B RCBO solutions providing smooth DC residual leakage detection (6mA DC sensitivity) to prevent nuisance tripping and ensure safety at EV charging stations.
High-selectivity MCBs and intelligent ACBs equipped with real-time telemetry to guarantee continuous uptime and zero-downtime selective fault tripping.
Modular sub-distribution panels incorporating OFKL and OFDZ47 MCBs with quick-busbar connections for fast modular installation and maintenance.
Heavy-duty MCCBs and isolators designed for high ambient temperatures, vibration resistance, and frequent motor-starting current surges.
IoT-enabled smart circuit breakers supporting remote telemetry, energy metering, and motorized automatic reclosing for remote property management.
A systematic look inside our Yueqing production hub, from raw material inspection to automated calibration.
Unlike standard assembly shops that rely solely on statistical sampling, OFA enforces a 100% full-inspection protocol across all completed current circuit breakers before packaging. Our multi-stage testing process includes:
Every single breaker unit passes through automated high-current impulse test benches to verify that its magnetic tripping coils fire within exact millisecond tolerances under short-circuit conditions (e.g., 5-10 $I_n$ for C-Curve).
Computer-controlled thermal calibration rigs pass continuous rated currents ($1.13 I_n$ and $1.45 I_n$) to adjust calibration screws on the bimetal strip, guaranteeing reliable anti-nuisance performance under ambient temperature variations.
Units undergo 2000V AC dielectric withstand testing across open contacts and between adjacent poles to ensure zero insulation breakdown and maximum safety during switching operations.
For residual current devices, zero-sequence current transformers (ZSCT) are tested for micro-ampere precision, verifying tripping within 30ms at nominal residual currents ($I_{\Delta n}$).
A streamlined four-step engineering roadmap for rapid prototyping, white-labeling, and mass production delivery.
Submit your electrical single-line diagrams, target standards (IEC, UL, CCC), breaking capacity requirements, and enclosure constraints. Our engineering sales team matches optimal baseline models within 24 hours.
We offer customized trip curve settings, private brand labeling, specialized laser markings, custom terminal screw configurations, and modified housing color palettes to suit your regional market identity.
Pre-production samples undergo full laboratory type testing. We provide complete test documentation and certificates before initiating mass production runs on automated assembly lines.
Secure sea, air, or express export packaging with full customs compliance documentation. Post-delivery, OFA provides ongoing technical support, firmware updates for smart units, and warranty coverage.
Read how industry professionals partner with OFA to achieve safe, efficient energy management.
"As a system integrator in Poland, we collaborated with OFA on several industrial automation projects. Their product range is comprehensive—from protective relays to communication gateways—simplifying our procurement. Product quality is consistent, eliminating commissioning delays."
"We purchased OFA's intelligent power monitoring devices to upgrade distribution panels in our manufacturing plant. Setup was simpler than expected, and they have operated stably for over a year. The granular electricity data helped us pinpoint unnoticed energy losses."
"Deploying OFA's RCBO and energy management solutions across commercial office buildings was a wise decision. Their team provided excellent remote technical guidance during installation. I highly recommend OFA for reliable building protection."
"Our solar PV projects in Chile required robust DC circuit breakers capable of enduring tough environmental conditions. OFA's DC MCCB line met our strict voltage and breaking requirements at an exceptional cost structure."
Clear, authoritative answers regarding our factory capabilities, product technicalities, and procurement terms.
Precision protection engineered for every tier of your power distribution framework.
OFA Electrical
