Explore our flagship circuit breakers designed for industrial, renewable, and commercial power architectures.
In modern industrial power systems, the Molded Case Circuit Breaker (MCCB) serves as the fundamental defense against severe electrical faults, thermal overloads, short circuits, and ground leakage anomalies. As a flagship China MCCB circuit breaker supplier and manufacturer, Wenzhou OFA Electrical Technology Co., Ltd. integrates decades of electromechanical engineering expertise with state-of-the-art automated manufacturing processes.
Founded in 2013 in Yueqing, Wenzhou—the world-renowned Capital of Electrical Appliances—OFA has spearheaded technical breakthroughs in arc-quenching dynamics, electronic trip unit (ETU) microprocessing, and contact material metallurgy. Our products deliver uncompromised system selectivity and high breaking capacity ($I_{cu}$) across complex industrial, solar PV, data center, and smart grid infrastructures.
Rooted in the core of China's low-voltage industrial cluster, OFA operates automated assembly lines, digital inspection centers, and environmental test chambers to guarantee product longevity in extreme industrial environments.
An in-depth whitepaper analysis of breaking mechanisms, thermal-magnetic physics, and system coordination.
When a high-magnitude short circuit occurs, contacts separate within milliseconds, forming an electrical arc exceeding 4000°C. OFA's MCCBs feature optimized de-ionizing arc chute grids constructed with specialized metallic splitter plates. These split, cool, and stretch the arc voltage above system operating voltage, forcing immediate current zero-crossing extinction.
Traditional bimetallic strips are augmented or replaced by digital signal processing (DSP) microprocessors in OFA's smart MCCB series. These units provide true RMS current sensing, immune to line harmonics, offering configurable LSI (Long-time, Short-time, Instantaneous) protective curves and real-time power parameters monitoring.
To prevent widespread blackout during local faults, OFA MCCBs deliver precise time-current discrimination. By coordinating $I_{cw}$ (short-time withstand current) and trip delays between downstream MCBs, main MCCBs, and upstream ACBs, only the faulty branch is isolated, ensuring continuous operation of critical facilities.
| Series Family | Rated Current ($I_n$) | Poles | Rated Operating Voltage ($U_e$) | Ultimate Breaking Capacity ($I_{cu}$) | Trip Unit Technology | Primary Industrial Application |
|---|---|---|---|---|---|---|
| BA88 Electronic Series | 63A - 800A | 3P / 4P | 400V / 690V AC | 50kA / 70kA / 100kA | Digital Microprocessor (ETU) | Smart Grids, Data Centers, Heavy Automation |
| DCM1 Series | 16A - 1250A | 3P / 4P | 400V / 690V AC | 35kA / 50kA / 65kA | Thermal-Magnetic Adjustable | Main Distribution Boards, Commercial HVAC |
| DCOF1 / OF1-250 PV DC | 63A - 250A | 2P / 4P | up to 1500V DC | 20kA / 35kA DC | High-Voltage DC Magnetic Arc Trap | Solar Photovoltaic Inverters, Battery ESS |
| BLTM3DC-250HU | 100A - 250A | 2P / 3P / 4P | up to 1000V DC | 25kA / 40kA DC | DC Specialized Quenching Chamber | EV Supercharging Hubs, Industrial DC Grids |
| OFA-M1 Series | 10A - 630A | 3P / 4P | 400V AC | 36kA / 50kA | Fixed Thermal & Magnetic | Standard Building Power Panels, OEM Machinery |
Tailored distribution switchgear protection engineered for severe, high-demand operational conditions.
Direct current (DC) arcs lack natural voltage zero-crossings, making breaking extremely difficult. OFA’s DCOF1 and BLTM3DC series incorporate elongated arc runners and permanent magnet arc blow-out fields specifically optimized for high-voltage DC combiner boxes, string inverters, and battery energy storage containers operating up to 1500V DC.
In mission-critical data infrastructure, power interruption leads to catastrophic losses. OFA provides high-speed MCCBs with zone selective interlocking (ZSI) and ultra-low internal resistance, minimizing heat dissipation inside high-density server racks while guaranteeing zero-nuisance tripping under harmonic loads.
Industrial motors generate high inrush currents upon startup. OFA MCCBs engineered with motor protection trip curves ($Class\ 10A / 20$) protect heavy machinery, compressors, and automated conveyer systems against phase loss, mechanical lockups, and sustained thermal overload without false tripping.
Fast-charging infrastructure requires robust defense against rapid power surges and potential leakage currents. Our integrated protection solution pairs high-interrupting MCCBs with sensitive RCBO/RCCB leakage modules to ensure safe operation for high-power DC fast chargers globally.
Navigating regional electrical standards requires an adaptable supplier equipped with international certification capabilities and custom OEM flexibility. OFA’s products conform strictly to IEC/EN 60947-2, UL 489, CE, CCC, and local safety norms across North America, Europe, Southeast Asia, and the Middle East.
Through strategic integration of automated manufacturing and local logistics channels, we ensure fast lead times, custom terminal configurations (tunnel terminals, spreaders, rear connections), and comprehensive technical support for large-scale engineering endeavors.
Pioneering the convergence of IoT connectivity, AI predictive analytics, and solid-state interruption.
Next-generation OFA MCCBs natively support Modbus-RTU, Ethernet IP, and wireless LoRaWAN protocols. Equipment operators can continuously stream real-time current, line voltage, contact temperature, and harmonic distortion data directly to central SCADA systems or cloud platforms.
By tracking thermal rise signatures and contact wear cycles during operation, integrated microprocessors predict potential contact degradation prior to failure, shifting facility operations from reactive repairs to planned predictive maintenance.
OFA's engineering team is actively researching semiconductor-based solid-state circuit breaking (SSCB) technologies. Combining power electronics with mechanical isolation delivers microsecond-level fault clearance, virtually eliminating mechanical contact arc erosion.
Comprehensive protection units covering every distribution layer from main service entrance to final sub-circuits.
Designed to make, carry, and break normal currents as well as fault currents under overload and short-circuit conditions in major industrial distribution boards.
Compact modular devices installed at final distribution points protecting terminal branch circuits against overcurrent and short circuits.
Intelligent Universal Air Circuit Breakers engineered for main low-voltage incoming feeders up to 6300A with intelligent communication controllers.
High-sensitivity residual current devices detecting leakage currents to protect personnel against direct/indirect electric shock and prevent electrically induced fires.
Precision engineering, digital testing stations, and lean assembly lines.
How OFA partners with engineering contractors, EPCs, and OEMs from consultation to field deployment.
Ideal for: Retrofits, standard commercial panels, distributed solar PV.
Ideal for: Multi-energy microgrids, heavy factory plants, regional automation.
See why global industry leaders rely on OFA for their critical electrical power systems.
"As a system integrator in Poland, we collaborated with OFA on industrial automation panels. Their MCCB and relay range simplified our procurement, and product consistency reduced on-site commissioning delays significantly."
"We purchased OFA's intelligent protection MCCBs for a workshop upgrade in Germany. Installation was smooth, thermal behavior under load has been rock-solid, and clear documentation saved us dozens of engineering hours."
"For our commercial facility management in Bangkok, OFA’s RCBO and MCCB devices provided detailed electrical protection. Their technical support team answered our single-line diagram queries within hours."
"Our PV project in Chile required robust DC circuit breakers capable of operating in high ambient heat. OFA's 1000V DC MCCBs met all parameters at competitive pricing."
Showcasing state-of-the-art power distribution tech at leading international trade expos.
Expert insights covering selection, compliance, OEM customization, and order logistics.
Explore more certified circuit breaker series from Wenzhou OFA Electrical Technology.
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