Engineered for extreme reliability, industrial power distribution, and commercial load management certified under international standards.
An engineering-focused analysis on how molded case circuit breakers drive operational continuity, electrical safety, and industrial productivity across global power grids.
The global demand for reliable low-voltage power distribution equipment has escalated dramatically due to industrial automation, urbanization, and energy transitions. Within modern electrical architectures, Molded Case Circuit Breakers (MCCBs)—exemplified by the OFA-M1 Series—serve as critical line protection devices. Operating across nominal current ratings from 63A to 630A, these breakers make, carry, and interrupt normal load currents while interrupting severe fault currents (such as short circuits and overloads) within milliseconds.
The OFA-M1 Series incorporates a multi-grid arc chute chamber paired with specialized silver-alloy contact tips. Upon fault detection, electromagnetic repulsion forces instantly open the contacts, driving the electric arc into the splitter plates where it is split, cooled, and extinguished. This limits let-through energy (I²t) and protects downstream transformer assets, cabling infrastructure, and sub-distribution switchboards from thermal and mechanical destruction.
Featuring dual-action protection, the OFA-M1 series combines an adjustable inverse-time thermal bimetal strip for overload protection with a instantaneous magnetic trip unit for short-circuit clearance. This dual mechanism prevents nuisance tripping caused by high inrush currents (such as motor start-ups) while ensuring instantaneous isolation during high-magnitude short circuits.
Professional Manufacturer from Yueqing, Wenzhou — The Capital of Electrical Appliances in China. Driving safety, reliability, and precision in power distribution equipment since 2013.
Founded in 2013, Wenzhou OFA Electrical Technology Co., Ltd. is rooted in Yueqing, Wenzhou—the heart of China's electrical industry and its largest low-voltage cluster. Owning independent proprietary brands such as "OFA", our product lines cover multiple industrial sectors including power grids, renewable energy, industrial automation, commercial construction, and equipment manufacturing.
We adhere to honest, transparent, and law-abiding operations, earning a Tax Credit Grade A rating for seven consecutive years. Our engineering team brings over a decade of deep technical accumulation in component R&D, automated assembly, and stringent quality verification.
Driving continuous progress in power distribution & control technology through strict engineering standards.
Explore our complete hardware engineering portfolio engineered for modern industrial power automation and renewable energy distribution.
Main breaker protection for heavy commercial panels and industrial switchgear. Protects against severe overloads, short circuits, and phase faults.
Compact modular protection for terminal distribution circuits, residential consumer units, smart building power control, and automation panels.
High-current intelligent main distribution unit designed for sub-stations, large industrial plants, data centers, and power utility incoming feed lines.
High-sensitivity earth leakage and shock protection, combining current imbalance protection with integrated overcurrent/short-circuit safety.
Innovatively integrates complete isolation functions with circuit switching, ensuring safe physical separation during maintenance and service operations.
Leveraging the unprecedented supply chain density of Yueqing, Wenzhou to deliver uncompromised electrical quality at competitive cost levels.
Yueqing houses the world's most concentrated ecosystem for electrical appliance raw materials, silver alloy contacts, BMC/DMC molding plastics, bi-metal strips, and precision stamping parts. This clustering enables OFA to minimize component transit lead times, lower sourcing logistics expenses, and respond dynamically to high-volume orders.
By pairing flexible automated assembly lines with rigorous digital inspection stations, OFA balances high production throughput with low scrap rates. Global buyers receive highly reliable MCCBs that meet strict IEC performance requirements at factory-direct wholesale pricing.
We provide full-spectrum private labeling, custom trip curve tuning (B, C, D curves for MCBs; thermal-magnetic adjustability for MCCBs), customized terminal connections, white-label packaging, and custom voltage ratings (e.g., 250V DC to 1500V DC for PV systems).
From modern power plants and solar microgrids to commercial facilities and data hubs, OFA components ensure seamless system stability.
DC power distribution in photovoltaic combiner boxes and battery energy storage systems (BESS) demands specialized arc handling due to the absence of natural AC zero-crossing points. Products like our OFBLT 3P 250HU High-Performance DC Molded Case Circuit Breaker provide high nominal DC operating voltage protection up to 1000V/1500V DC, securing solar array string inputs.
In high-density commercial real estate, multi-tenant complexes, and retail centers, the OFA-M1 125A to 400A MCCBs act as reliable main distribution panel isolators, preventing cascade failures and facilitating easy selective tripping configuration.
Heavy machinery, CNC equipment, automated conveyances, and pump drives subject breakers to intense vibration, thermal cycling, and high magnetic inrush. OFA MCCBs feature reinforced thermosetting shells (BMC) that resist mechanical stress and elevated ambient temperatures.
Electric vehicle fast-charging infrastructure requires non-stop availability combined with leakage current safety. Pairing our OFA-M1 MCCBs with high-sensitivity RCBO/RCCB modules shields critical power conversion electronics against transient line spikes and ground fault risks.
Comprehensive technical data sheet designed for electrical engineers, panel builders, EPC procurement specialists, and system integrators.
| Model Series | Rated Current (In) | Poles (P) | Rated Insulation Volt (Ui) | Ultimate Breaking Capacity (Icu) | Service Breaking Capacity (Ics) | Compliance Standards |
|---|---|---|---|---|---|---|
| OFA-M1-63 | 16A, 25A, 32A, 40A, 50A, 63A | 3P / 4P | 800V AC | 35kA (400V) | 100% Icu | IEC 60947-2, CE, CCC |
| OFA-M1-125 | 63A, 80A, 100A, 125A | 3P / 4P | 800V AC | 50kA (400V) | 75% Icu | IEC 60947-2, CE, CCC |
| OFA-M1-250 | 125A, 160A, 200A, 225A, 250A | 3P / 4P | 800V AC | 50kA / 65kA | 75% Icu | IEC 60947-2, CE, CCC |
| OFA-M1-400 | 250A, 315A, 350A, 400A | 3P / 4P | 1000V AC | 65kA / 85kA | 75% Icu | IEC 60947-2, CE, UL Optional |
| OFA-M1-630 | 400A, 500A, 630A | 3P / 4P | 1000V AC | 65kA / 85kA | 75% Icu | IEC 60947-2, CE, CCC |
| OFBLT-250HU (DC) | 100A, 125A, 160A, 200A, 250A | 2P / 3P / 4P | 1500V DC | 25kA (1000V DC) | 100% Icu | IEC 60947-2 (DC), CE |
Clear, systematic paths engineered for both standard distribution orders and custom industrial OEM/ODM collaborations.
Ideal for: Panel builders, regional electrical wholesalers, and commercial retrofits seeking reliable, proven MCCBs & MCBs with short lead times.
Ideal for: Global electrical brands, specialized equipment OEMs, solar inverter manufacturers, and large infrastructure projects.
From passive overload tripping to active AI-driven fault prediction and smart SCADA integration.
Modern electrical power networks are transitioning from traditional "passive tripping after a fault" to "active prediction before failure". Next-generation smart MCCBs integrate micro-sensors measuring contact temperature rise, mechanical operating cycles, and harmonic distortions. OFA is actively investing in IoT edge-connected controllers for early thermal anomaly warnings.
Environmental responsibility is paramount. OFA prioritizes halogen-free, flame-retardant thermoplastics, recyclable arc chutes, and RoHS/REACH compliant silver-tin-oxide (AgSnO2) contacts, eliminating toxic heavy metals while elevating contact welding resistance.
For ultra-critical DC microgrids and high-frequency power electronics, solid-state circuit breaking technologies offer sub-millisecond trip times without mechanical wear, shaping the future of industrial power security.
Discover why global industry leaders, system integrators, and facility engineers trust OFA for critical power protection.
"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 MCCBs and communication gateways, which simplifies our procurement and integration work. Product quality is consistently reliable."
"We purchased OFA's intelligent power monitoring devices and OFA-M1 MCCBs to upgrade the power distribution system in our plant. Installation was simpler than expected, and integration went smoothly. Most importantly, they have operated flawlessly for over a year."
"Deploying OFA's circuit protection and energy management solutions across several commercial office complexes was a wise decision. The system helped us gain detailed insight into electrical loads while maintaining total fire and short-circuit safety."
"Our PV solar project required high-voltage DC protection equipment. OFA's OFBLT 250HU DC breakers met our exact specs at a reasonable price point. Their technical support engineers provided excellent remote guidance throughout."
Engaging with worldwide electrical partners to advance low-voltage safety standards globally.
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High-performance miniature circuit breakers, DC breakers, and specialized isolation gear for global procurement.
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