Explore our primary certified circuit breakers manufactured under ISO9001 standards for high-capacity industrial, solar PV, and commercial distribution boards.
In modern electrical distribution architecture, the Miniature Circuit Breaker (MCB) serves as the critical terminal node safeguarding infrastructure against catastrophic thermal overloads and electro-magnetic short circuits. As global energy grids transition toward decentralized renewable sources, high-density industrial automation, and ultra-reliable data center networks, the engineering requirements for low-voltage switchgear have surged exponentially.
Modern industrial loads exhibit complex inrush profiles. Our MCB lines integrate dual-element tripping mechanisms—bimetallic strips for calibrated inverse-time delay thermal overload protection, and electro-magnetic solenoids for instantaneous short-circuit fault interruption within milliseconds.
Extinguishing electric arcs generated during breaking at 10kA or 15kA capacity requires zero-delay cooling. Incorporating 12 to 14 grid splitter plates in specialized polyamide housing allows rapid arc stretching, de-ionization, and safe gas venting.
Engineered with silver-alloy contacts (AgNi/AgCdO) to eliminate contact welding, housed in glass-fiber reinforced Nylon 66 (PA66) meeting UL94-V0 standard, ensuring robust fire insulation under severe thermal stress up to 960°C glow-wire test.
Rooted in Yueqing, Wenzhou—the world-renowned Capital of Electrical Appliances in China—Wenzhou OFA Electrical Technology Co., Ltd. was established in 2013. We specialize in the complete lifecycle of low-voltage distribution switchgear and control gear equipment, combining proprietary R&D, precision tooling, and smart manufacturing.
Operating under strict ISO9001 Quality Management Systems, OFA has sustained an unbroken track record of compliance and excellence, earning recognition as a Tax Credit Grade A Enterprise for seven consecutive years. Our brand portfolio, featuring "OFA", serves critical infrastructure projects, equipment builders, and global energy conglomerates across Europe, South America, Southeast Asia, and the Middle East.
Our facility houses modern assembly automation, high-speed stamping presses, laser calibration rigs, and comprehensive full-process type testing laboratories that verify mechanical endurance, temperature rise limits, and insulation breakdown voltages under simulated environmental extremes.
Choosing the precise miniature circuit breaker demands rigorous evaluation of electrical parameters, operational environment, pole count, and fault-current interrupt levels. The following engineering matrix highlights key specifications across OFA’s primary switchgear families.
| Series Line | Breaker Type | Rated Current ($I_n$) | Breaking Capacity ($I_{cn}$) | Tripping Curves | Standards Compliance |
|---|---|---|---|---|---|
| OF6KA Series | MCB (Standard Commercial) | 1A - 63A | 6,000A (6kA) | B, C, D | IEC/EN 60898-1, CE |
| OF10KA C65 | MCB (Heavy Industrial) | 1A - 63A | 10,000A (10kA) | B, C, D, K | IEC/EN 60947-2, UL 489 |
| OFD4Z7 Series | MCB (Multi-Pole 1P-4P) | 6A - 125A | 10kA / 15kA | C, D | IEC 60947-2, GB/T 14048.2 |
| DCOF1-125/PV | DC MCB (Solar Photovoltaic) | 10A - 125A | Up to 1500V DC (10kA) | PV Special | IEC 60947-2, EN 60947-2 |
| OFDX / OFGX | RCCB / Residual Current | 16A - 100A | $I_{\Delta n}$: 30mA, 100mA, 300mA | Type AC, Type A, Type B | IEC/EN 61008-1 |
| NB1L / OFAP6 | RCBO (Combined Overcurrent) | 6A - 40A | 6kA / 10kA | B, C + Earth Leakage | IEC/EN 61009-1 |
| BA88-400E | MCCB (Molded Case) | 100A - 400A | 35kA / 50kA | Thermal-Mag / Electronic | IEC 60947-2 |
| OFIS-125A | Isolator Switch (IS) | 32A - 125A | $I_{cw}$: 12$I_n$ 1s | Non-automatic Isolation | IEC/EN 60947-3 |
Low-voltage protection gear must perform impeccably across diverse operational ecosystems. OFA provides engineered circuit breaker deployment configurations tailored to the harsh realities of each environment.
PV arrays create continuous high DC voltages where natural zero-crossing of current is absent. The DCOF1-125/PV series uses permanent magnet arc-chutes to pull DC arcs into quenching chambers, preventing flashover risks in 1000V/1500V DC string boxes and energy storage enclosures.
Data centers demand high discrimination (selectivity) to isolate branch faults without causing upstream breaker trips. OFA’s 10kA C65 breakers offer tight magnetic pickup tolerances, safeguarding non-stop IT server racks and redundant UPS units from cascade outages.
Electric vehicle supply equipment (EVSE) experiences smooth DC fault currents alongside AC components. Utilizing Type A/B RCCBs (OFDX/OFGX) prevents residual DC currents from saturating standard transformers, maintaining full earth-leakage tripping sensitivity.
Compact DIN-rail enclosures demand space-saving single-module 1P+N RCBOs. OFA’s space-optimized breakers provide overload, short-circuit, and 30mA personal shock protection in a 18mm slim body, reducing distribution panel footprint by 50%.
Electric motors produce severe initial current spikes up to 10 to 14 times rated current ($I_n$). OFA D-curve and K-curve MCBs prevent nuisance tripping during motor startup while remaining hypersensitive to locked-rotor faults.
Railways, street lighting, and water treatment plants require broad temperature tolerance (-35°C to +70°C) and tropicalized humidity resistance. OFA switchgears undergo anti-salt spray and humidity testing for reliable tropical and coastal execution.
Quality is an absolute requirement at Wenzhou OFA. Every single breaker off our assembly line must navigate rigorous Standard Operating Procedures (SOPs) under strict international standards.
Unlike factories relying on basic batch sampling, OFA enforces a 100% full-inspection system prior to packaging. Automated test benches verify:
OFA products comply with global statutory directives, facilitating smooth customs clearance and grid connection approvals worldwide:
The power distribution industry is evolving from passive fault interruption to active intelligent prediction. OFA's engineering teams are pushing boundaries along three strategic innovation tracks.
Perfecting thermal-magnetic trip accuracy, compact 18mm RCBO designs, and expanding DC high-voltage breaking capabilities up to 1500V DC for utility solar installations.
Embedding micro-sensors, RS485 Modbus, and wireless Modbus/Wi-Fi/Zigbee chips inside DIN-rail MCBs for real-time power measurement, remote tripping, and temperature anomaly alerts.
Developing semiconductor hybrid breakers capable of microsecond fault clearance (<10 microseconds), zero arcing, and infinite mechanical lifespan for DC microgrids and AI data centers.
From technical parameter matching to global project delivery, we provide an engineering-first, transparent 5-step collaborative process.
Analyze site voltage, short-circuit current levels, ambient conditions, and certification needs.
Select breaker model, calibrate trip curves, and provide full drawing topology verification.
Rapid prototype lab production followed by temperature rise and dielectric test validation.
Lean automated line manufacturing under 100% full-inspection SOP protocols.
Technical and commercial clarity for wholesalers, system integrators, EPC engineers, and OEM partners.
Explore additional high-performance industrial switchgears, DC PV circuit breakers, and residual protection devices from our catalog.
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