Directly sourced from factory automated production lines, meeting international standards IEC/EN 60898-1 and IEC 60947-2.
In modern industrial, commercial, and residential electrical networks, the reliability of low-voltage distribution terminal protection is the absolute cornerstone of system stability. The OF6KA Series Miniature Circuit Breaker (MCB) engineered by Wenzhou OFA Electrical Technology Co., Ltd. represents a state-of-the-art solution designed to instantly interrupt overload currents and short-circuit fault currents up to 6,000 Amperes (6kA).
Compliant with international standards including IEC/EN 60898-1 and IEC 60947-2, the OF6KA Series integrates high-precision thermal-magnetic tripping mechanisms. Its primary purpose is to safeguard conductors, connected equipment, and downstream sub-circuits against thermal degradation caused by sustained overloads, as well as catastrophic electrodynamic destruction resulting from phase-to-phase or phase-to-neutral short circuits.
Why specify 6kA rated MCBs? In modern urban distribution networks, transformer capacities are increasing, leading to lower grid impedance and elevated prospective fault currents ($I_{cp}$). Installing 6kA protection ensures that branch circuits maintain a robust safety margin, preventing contact welding and arc flash hazards during severe fault conditions.
Why leading global EPCs, OEMs, and electrical distributors source their core distribution components from Wenzhou OFA Electrical Technology Co., Ltd.
Situated in Yueqing, Wenzhou—universally recognized as the "Capital of Electrical Appliances in China"—OFA operates at the center of the world's densest low-voltage supply ecosystem. Raw material sourcing, precision silver-alloy contact riveting, stamped copper terminals, and high-dielectric molded housings are consolidated within a 15-kilometer radius, slashing production lead times by up to 40%.
Every OF6KA breaker undergoes fully automated assembly and computerized calibration. Thermal bimetallic strip bending is calibrated using high-precision laser adjustment stations, while magnetic trip solenoids are tested against 100% full-inspection SOPs. Mechanical life cycles exceed 20,000 operations, while electrical endurance guarantees 10,000 operational cycles under rated loads.
By leveraging massive production volumes and vertically integrated sub-assembly production, Wenzhou OFA eliminates intermediary distributor markups. Our customers receive premium circuit protection hardware that meets European safety standards at a highly competitive factory-direct price point, maximizing profitability for procurement projects.
Navigating energy transition, smart building automation, and high-density industrial electrification.
The global push for net-zero carbon emissions has accelerated the adoption of distributed solar microgrids and battery energy storage systems (BESS). The OF6KA Series, along with our specialized DC Molded Case Circuit Breakers (such as the OF1-125/PV DC MCCB), provides essential overcurrent protection for solar combiners, inverter AC output panels, and battery rack management units.
These units withstand bidirectional power flows and ambient temperature fluctuations typically encountered in harsh outdoor solar plant environments.
Electric Vehicle Supply Equipment (EVSE) demands high electrical reliability due to continuous long-duration loads and potential residual harmonic currents. OF6KA MCBs, paired with our Type A / Type B Residual Current Circuit Breakers (RCCB/RCBO), prevent nuisance tripping while providing total fault isolation for Level 2 AC chargers and DC fast-charging auxiliary sub-panels.
Modern data centers and intelligent commercial towers demand absolute uptime. High power density racks generate steep inrush currents upon startup. The OF6KA Series with Type D tripping characteristics prevents unnecessary trips during transformer energization while maintaining instant magnetothermal response to actual short-circuit events, preventing cascading network outages.
While traditional MCBs safeguard against line overloads and short circuits, modern installation codes (such as BS 7671 and IEC 60364) increasingly recommend combining overcurrent protection with earth leakage detection. OFA's integrated RCBO product lines (like the OFC 32A Series) merge MCB breaking performance with micro-ampere residual leakage tripping in a single modular width.
An inside look at the high-grade components that guarantee reliable 6kA arc quenching and thermal protection.
Engineered with 12 parallel insulated steel arc splitter plates. Upon contact separation during a 6kA short-circuit event, the electromagnetic force drives the electric arc rapidly into the chute, splitting it into series sub-arcs and cooling it within milliseconds to prevent housing rupture.
Utilizing high-purity AgCdO/AgZnO contact rivets designed to resist material transfer and thermal erosion. Contact resistance is minimized to ensure extremely low watt loss per pole, easily surpassing energy efficiency standards.
Calibrated bimetallic strip with differential thermal expansion coefficients. Ensures inverse time-delay tripping action under moderate overcurrent conditions, accommodating temporary operational transients while disconnecting true overloads.
A trusted partner in power distribution, control equipment, and low-voltage electrical component manufacturing since 2013.
Wenzhou OFA Electrical Technology Co., Ltd. is one of the professional suppliers of distribution switchgear and control equipment in China. Founded in 2013, the company is rooted in Yueqing, Wenzhou — the Capital of Electrical Appliances in China. It owns independent brands such as "OFA", and its products cover multiple industries and applications including power, energy, industrial automation, construction, and equipment manufacturing.
We are committed to enabling power systems to operate safer and smarter through products and services that integrate industry best practices, independent R&D, and strict quality control. Adhering to honest and law-abiding operations, we have been rated as tax credit grade A for seven consecutive years, earning the long-term trust of numerous global partners.
Deploying OF6KA breakers and distribution switchgear across high-demanding sectors.
Mounted inside consumer units and flush-mount distribution boards to safeguard lighting circuits, socket outlets, and home HVAC units from electrical overloads.
Serving sub-distribution boards in office towers, retail centers, and hotels, providing selective coordination between main MCCBs and downstream branch circuits.
Installed inside machine control cabinets, PLC power supplies, variable frequency drives (VFDs), and robotics control assemblies demanding high immunity to nuisance trips.
Protecting AC side outputs of string inverters, solar pumping systems, and commercial rooftop photovoltaic power generation arrays.
Providing feeder protection inside Power Distribution Units (PDUs) supplying critical server racks and backup Uninterruptible Power Supplies.
Applied in municipal street lighting systems, water treatment plants, rail transit auxiliary panels, and smart grid distribution terminals.
How international buyers, EPC contractors, and brand owners initiate new projects with OFA Electrical Technology.
Review technical parameters (voltage, current rating, breaking capacity, trip curve B/C/D) and submit project specifications for precise matching.
OFA engineers provide complete topological system configuration lists, BOM calculation, and sample units for laboratory type testing.
Upon order confirmation, lean manufacturing principles guarantee fast turnaround, automated assembly, and strict in-process inspection.
Secure export packaging, complete customs documentation, FOB/CIF delivery arrangements, and continuous lifecycle technical support.
Explore our comprehensive range of high-performance protection devices.
See why global industry leaders rely on OFA for their low-voltage electrical systems.
"As a system integrator, our company has collaborated with OFA on several industrial automation projects. Their product range is quite comprehensive, covering everything from protective relays to communication gateways, which simplifies our procurement and integration work. The product quality is consistent, reducing on-site commissioning hassles."
"We purchased OFA's intelligent power monitoring devices to upgrade the power distribution system in our old workshop. The installation and setup were simpler than expected, and integration with our existing system went smoothly. Most importantly, they have been running very stably for over a year."
"Our PV project required reliable communication management and data acquisition equipment. OFA's products met our core needs at a reasonable price and could adapt to our local outdoor environment. Their engineers provided excellent configuration guidance via email and video calls."
Comprehensive answers regarding OF6KA breakers, factory capabilities, and global procurement terms.
Complete your low-voltage system setup with our factory-direct products.
OFA Electrical
