Direct Factory Supply | High Interruption Capacity | IEC & CE Certified Distribution Switchgear
Precision Engineering from Yueqing — The Low-Voltage Electrical Capital of China
Founded in 2013, Wenzhou OFA Electrical Technology Co., Ltd. has established itself as an authoritative manufacturer and global supplier of distribution switchgear, control equipment, and low-voltage protection components. Situated in Yueqing, Wenzhou—the globally recognized core cluster of China's electrical apparatus industry—OFA leverages over a decade of continuous manufacturing refinement, independent technical R&D, and stringent quality governance.
Enterprise Integrity & Quality Credibility
OFA operates under strict compliance standards and has been awarded Tax Credit Grade A for seven consecutive years. With ISO9001 certified manufacturing facilities and compliance with international benchmarks including IEC 60947-2, CE, and CCC, we ensure that every OFBLT Series unit delivered provides uncompromised circuit safety.
Our dedicated R&D team delves deep into arc-extinguishing physics, thermal dissipation dynamics, and mechanical endurance. Equipped with full-process type testing devices, we verify dielectric strength, temperature rise limits, and short-circuit withstand values under extreme operational stresses.
Utilizing automated assembly matrixes, automated calibration units, and digital inspection stations, OFA strictly governs every step from raw silver-alloy contact inspection to final molding. This ensures near-zero factory defect rates and tight tolerance consistency.
Relying on the complete local raw-material ecosystem of Yueqing, we eliminate supply chain markups, allowing us to offer premium OEM/ODM solutions and rapid turnarounds for urgent, large-scale utility projects.
High-Breaking DC & AC Molded Case Circuit Breaker (MCCB) Breakthroughs
Modern electrical power architectures are experiencing a paradigm shift driven by the rapid global proliferation of high-voltage solar Photovoltaic (PV) plants, Battery Energy Storage Systems (BESS), Electric Vehicle (EV) fast-charging hubs, and DC microgrids. Traditional AC circuit breakers fail to meet the harsh arc-quenching requirements of high-voltage DC circuits, where zero-crossing point absence makes arc extinction exceptionally difficult. The OFBLT Series Molded Case Circuit Breaker (MCCB) is purpose-built to solve these electrical protection challenges.
The OFBLT Series incorporates a specialized magnetic blowout grid assembly paired with ultra-durable arc chutes. When a high-magnitude short-circuit fault occurs in a DC system (up to 1500V DC), the persistent electrical arc is rapidly driven by powerful electromagnetic forces into the splitter plates. Here, the arc is split into multiple sub-arcs, cooled rapidly, and extinguished in milliseconds. This prevents contact erosion and protects upstream transformers and inverter banks from destructive thermal damage.
Featuring a dual-action protection topology, the OFBLT Series provides:
Molded from high-grade thermosetting BMC/DMC composite resins, the outer casing of the OFBLT Series exhibits exceptional tracking resistance (CTI > 600V), superior mechanical impact resistance, and high-temperature dimensional stability. This renders the series optimal for harsh industrial environments, including desert solar installations, marine offshore energy platforms, and chemical manufacturing facilities.
| Parameter | OFBLT-250HU / BLTM3DC | OFBLT-320A / 2P | OFBLT-800H / 2P-3P |
|---|---|---|---|
| Rated Operational Current ($I_n$) | 100A, 125A, 160A, 200A, 250A | 250A, 300A, 320A | 400A, 500A, 630A, 800A |
| Rated Operational Voltage ($U_e$) | 500V DC to 1000V DC | 750V DC / 415V AC | 1000V DC to 1500V DC |
| Ultimate Short-Circuit Breaking Capacity ($I_{cu}$) | 35kA / 50kA | 50kA | 65kA / 100kA |
| Service Short-Circuit Breaking Capacity ($I_{cs}$) | 100% $I_{cu}$ | 75% $I_{cu}$ | 75% - 100% $I_{cu}$ |
| Poles Available | 2P, 3P, 4P | 2P | 2P, 3P |
| Insulation Voltage ($U_i$) | 1200V | 1000V | 1500V |
| Impulse Withstand Voltage ($U_{imp}$) | 8kV / 12kV | 8kV | 12kV |
| Standard Compliance | IEC 60947-2, GB/T 14048.2 | IEC 60947-2 | IEC 60947-2, CE Certified |
Where the OFBLT Series Protects Critical Power Infrastructure
In utility-scale photovoltaic plants operating at 1000V to 1500V DC, OFBLT MCCBs serve as primary isolation and protection units inside combiner boxes and central inverter stations, mitigating back-feed currents from high-capacity PV arrays.
Containerized lithium-battery energy storage facilities demand rapid fault breaking to prevent catastrophic thermal runaway. The OFBLT Series guarantees swift interruption during short-circuit occurrences between battery racks and DC-bus converters.
Commercial megawatt EV fast-charging stations convert grid AC power into continuous high-amperage DC output. OFBLT circuit breakers shield rectifiers and charging dispensers against transient overcurrents.
Steel mills, paper manufacturing lines, and automated assembly facilities rely on OFBLT MCCBs to deliver continuous, reliable power to heavy DC motor drives and distribution switchboards without nuisance tripping.
Supply Chain Synergies, Efficiency, & Uncompromised Quality Control
Sourcing low-voltage switchgear components directly from Wenzhou OFA Electrical Technology Co., Ltd. presents significant economic and operational advantages for international EPC contractors, panel builders, and electrical distributors:
A Streamlined 4-Step Process for Engineering Projects & Custom Orders
Submit your single-line diagrams, target voltage ($U_e$), operating current ($I_n$), breaking capacity ($I_{cu}$), and application scenario. Our technical engineering group analyzes your specs within 24 hours.
We provide rapid prototype samples for customer validation. Devices undergo dielectric, thermal rise, and short-circuit verification in lab conditions to ensure exact alignment with project parameters.
Upon sample sign-off and order confirmation, production commences on our automated lines under ISO9001 governance. Raw components are systematically tracked via barcode management systems.
Goods are standard export-packaged with sea/air-freight protection. OFA engineers provide ongoing lifecycle documentation, wiring guides, and remote commissioning support.
Systemic Electrical Protection & Control Products Manufactured by OFA
Molded Case Circuit Breakers designed to make, carry, and break currents under normal and abnormal fault conditions. Includes BA88 Electronic, DCM1, DCOF1, OFM1, OFBLT, OF1, and OFA-M1 Series.
Miniature Circuit Breakers for commercial and residential branch distribution. Includes OF6KA, OF10KA C65, OFAFT, OFD4Z7, OFDL, OFDP, OFDZ47, OFEU, OFKL, OFL7, OFL8, OFNC, and OFPF Series.
Intelligent Air Circuit Breakers serving as high-capacity main protection units for industrial transformers and main switchboards. Product spotlight: OFW1 Intelligent Universal Circuit Breaker.
Residual Current Breakers with Overcurrent Protection for personal electric shock safety and equipment earth fault protection. Models include OFAP6-AC, OFDPN, OFDX, OFGX, OFID, OFPM, OFC, NB1L, and OFMIN.
Innovatively integrates the complete protective functions of circuit breakers with reliable load isolation mechanisms. Featured lines include OFIS-125A, OFIS-BH, and OFIS-DS Series.
Validated Performance across European, Asian, and South American Projects
"As a system integrator, our company has collaborated with OFA on several industrial automation projects in Poland. Their product range is quite comprehensive, covering everything from MCCBs to communication gateways, which simplifies our procurement and integration work."
— Andrzej Nowak, Technical Director (Poland)
"We purchased OFA's intelligent power monitoring and circuit protection devices to upgrade our workshop distribution system in Germany. They have been running stably for over a year, and the quality standard is exceptionally solid."
— Markus Weber, Maintenance Manager (Germany)
"Our solar PV project in Chile required high-voltage DC protection breakers. OFA's OFBLT DC Series met our core technical parameters at an exceptional price point while standing up to high outdoor ambient temperatures."
— Carlos Rivera, Site Lead Engineer (Chile)
Technical, Sourcing, and Operational Insights for Purchasing Directors & Engineers
A: Alternating Current (AC) inherently passes through a natural "zero voltage" point 100 or 120 times per second, which assists in extinguishing electric arcs. Direct Current (DC) maintains constant voltage and current direction without natural zero points, creating severe, sustained arc plasma during interruption. The OFBLT Series is engineered with enhanced magnetic arc-extinction chutes, permanent blowout magnets, and lengthened contact distances specifically designed to stretch, cool, and extinguish intense DC arcs safely up to 1500V DC.
A: Yes. OFA offers flexible custom engineering for OEM clients. We can adjust thermal-magnetic trip thresholds, customize electronic trip unit parameters, supply specialized busbar terminal connections, and provide full private-label branding for panel builders and equipment vendors.
A: OFA products are designed and tested according to rigorous international electrotechnical standards, primarily IEC 60947-2 (Low-voltage switchgear and controlgear - Circuit-breakers) and IEC 60898-1. Our products carry CE certification, and our manufacturing facilities operate under ISO9001 quality management system certification.
A: Standard stock models and components can be dispatched within 7 to 10 days. For large-scale customized OEM production orders (e.g., 5,000+ units), lead time is generally 20 to 30 days depending on component customization. Our factory's automated assembly capabilities ensure reliable delivery for project-critical deadlines.
A: Standard calibration for OFBLT thermal-magnetic breakers is conducted at +40°C. When operating in extreme high-temperature environments (such as unvented solar combiner boxes exposed to desert sunlight up to +60°C), temperature derating factors must be applied to prevent premature nuisance tripping. Detailed derating charts are available in our technical product manuals.
A: Yes. We provide end-to-end technical support for international clients, including pre-project single-line review, selection guidance, AutoCAD dimensional drawings, custom wiring schematics, and video-assisted installation and commissioning support.
Explore Our Full Portfolio of High-Performance Electrical Protection Devices
Contact Wenzhou OFA Electrical Technology Co., Ltd. today to consult with our application engineers, request engineering CAD models, or obtain direct factory pricing for your upcoming commercial projects.
Request Factory Quotation & Technical Catalog →
OFA Electrical
