Explore our specialized range of high-breaking capacity DC Miniature Circuit Breakers, Residual Current Breakers, and Molded Case units manufactured under certified ISO9001 quality systems.
The worldwide shift toward carbon neutrality has accelerated the adoption of high-voltage Direct Current (HVDC) and low-voltage DC distribution architectures across commercial, industrial, and utility infrastructure.
Modern PV string architectures have evolved from 600V DC to 1000V DC and 1500V DC operating thresholds to optimize efficiency. Breakers must sustain elevated continuous DC voltage, mitigate high ambient thermal loads in combiner boxes, and isolate bidirectional fault currents reliably.
Industrial scale and residential energy storage systems feature extremely high short-circuit current dynamics. High DC fault current rise rates ($di/dt$) demand protective breakers with ultra-fast arc extinction times (<5ms) to prevent catastrophic thermal runaway and safeguard battery modules.
DC Fast Charging (DCFC) hubs and 48V/400V DC telecom data centers require ultra-reliable non-polarized and polarized DC Miniature Circuit Breakers. Precise overcurrent tripping prevents downtime while maintaining continuous equipment uptime.
Unlike Alternating Current (AC) electrical systems where current naturally crosses zero 100 or 120 times per second, Direct Current (DC) maintains a continuous magnitude without natural zero-crossing points. Breaking a DC arc requires advanced physical arc stretching, cooling, and permanent magnetic blowout field manipulation.
| Performance Feature | Standard AC Circuit Breakers | OFA High-Performance DC MCBs | Engineering Significance |
|---|---|---|---|
| Arc Interrupt Mechanism | Relies on natural current zero-crossing point. | Permanent magnetic blowout + extended arc chute plates. | Rapidly forces arc into de-ionizing grid even at continuous high DC voltage. |
| Polarity Sensitivity | Non-polarized (Direction independent). | Polarized or Specialized Non-Polarized options. | Prevents contact erosion and catastrophic arc runaway during reversed current flow. |
| Contact Material | Standard Silver-Cadmium Oxide ($AgCdO$). | High-purity Silver-Graphite / Silver-Tin Oxide ($AgSnO_2$). | Eliminates contact welding during short-circuit events up to 10kA–20kA. |
| Magnetic Trip Threshold | Curve B (3-5 In), C (5-10 In), D (10-14 In) AC. | Calibrated DC curves (e.g., 7-15 In DC equivalent). | Prevents nuisance tripping during initial capacitive and inductive solar inrush currents. |
OFA’s DC Miniature Circuit Breakers incorporate strategically positioned high-coercivity permanent magnets within the arc chamber. As contacts open, the Lorentz force drives the electric arc at supersonic speeds into the metal arc runner, splitting and quenching the arc in under 5 milliseconds.
Features bi-metallic strips designed for precise long-time inverse thermal overload protection, alongside an electromagnetic instantaneous short-circuit trip coil calibrated specifically for DC current waveforms.
To safely isolate high DC voltages up to 1000V or 1500V, multiple poles (up to 4P) are connected in series. This divides the total system arc voltage across multiple break gaps, providing maximum insulation coordination and thermal safety.
From end-of-line miniature protection to high-capacity air circuit breakers, Wenzhou OFA Electrical Technology Co., Ltd. supplies a comprehensive spectrum of power control components.
Primary protection device engineered to make, carry, and break currents under normal and abnormal conditions (short circuit and overload protection). Available in BA88, DCM1, DCOF1, OFM1, OFBLT, OF1, and OFA-M1 series.
The primary safe guardian for modern low-voltage systems. Includes OF6KA, OF10KA C65, OFAFT, OFD4Z7, OFDL, OFDP, OFDZ47, OFEU, OFKL, OFKL-NXB, OFL7, OFL8, OFNC, OFPF, and OFP series.
High-performance protection for industrial distribution trunks (OFW1 Intelligent Universal Circuit Breaker) and compact isolating switches (OFIS-125A, OFIS-BH, OFIS-DS Series).
Advanced earth leakage and personnel protection units including OFAP6-AC, OFDPN, OFDX, OFGX, OFID, OFPM, OFC, OFKL-80A, NB1L, OFMIN, OFOM, and OFR1 series.
Engineered to operate seamlessly across demanding environmental conditions, our electrical protection devices ensure uncompromised system resilience.
Guarding domestic Rooftop PV systems, energy storage batteries, and residential distribution boards against overcurrent and leakage risks.
High-density panelboard breaker integration providing reliable sub-circuit protection for office towers, shopping centers, and smart facilities.
Protecting PLC cabinets, robotic motor drives, automated conveyor lines, and heavy equipment distribution units.
1000V DC and 1500V DC rated MCBs and MCCBs deployed inside multi-string solar combiner boxes and central inverter stations.
Ensuring steady-state DC power delivery for UPS battery banks, server rack distribution units (PDUs), and HVAC control systems.
DC Miniature and Molded Case circuit protection installed within ultra-fast DC charger cabinets to safeguard power electronics modules.
High breaking capacity breakers preventing thermal overload and rapid short-circuit damage in megawatt-scale battery energy storage systems.
Deployments across municipal transit, electrified rail systems, port container cranes, and municipal public lighting projects.
Founded in 2013, Wenzhou OFA Electrical Technology Co., Ltd. is rooted in Yueqing, Wenzhou — the heart of China's low-voltage electrical industry. With independent brand identity ("OFA"), we deliver robust power distribution switchgear, control equipment, and OEM/ODM solutions across global energy and industrial automation markets.
Our technical team continues to delve deep into R&D. Equipped with full-process type testing and factory inspection devices, we execute rigorous verification of mechanical life, temperature rise, and insulation performance on all DC MCBs and switchgear.
Automated assembly lines and digital inspection stations ensure every step from raw silver-contact stamping to finished circuit breakers is governed by 100% full-inspection standard operating procedures (SOPs), minimizing factory defect rates.
Upholding honest operations, OFA has been rated as Tax Credit Grade A for seven consecutive years. We manage long-term strategic partnerships across 50+ countries with custom packaging and rapid delivery capabilities.
Compliance is non-negotiable in critical energy infrastructure. All OFA DC Miniature Circuit Breakers and low-voltage protection devices strictly conform to international electrotechnical standards.
Standard specification governing low-voltage switchgear and controlgear circuit breakers for industrial low-voltage and DC applications, covering dielectric strength, thermal endurance, and breaking capacity.
Rigorous verification for circuit breakers intended for photovoltaic (PV) systems, providing high safety margin compliance across North American, European, and global markets.
Certified factory-wide quality management ensuring batch-to-batch traceability, raw material verification, micro-ohm contact resistance testing, and standardized calibration.
As power grids evolve toward decentralized microgrids and software-defined power systems, OFA is pioneering smart protection hardware integration.
Optimization of non-polarized DC breakers with dual permanent magnetic blowout channels, reaching continuous ratings up to 1500V DC in standard DIN-rail modular widths.
Embedding RS485 / Modbus-RTU communication, real-time power metering, and active arc fault detection (AFCI) directly into modular breakers for remote SCADA cloud monitoring.
Development of semiconductor-based solid-state circuit breaker (SSCB) topologies enabling microsecond ($μs$) trip speeds for sensitive microgrids and energy storage hubs.
Whether procuring standard energy management components or developing tailored OEM breaker solutions, our engineering team supports your full project lifecycle.
Analysis of site voltage ($U_e$), operating current ($I_n$), prospective fault currents ($I_{cu}$), ambient operating temperatures, and protocol integration needs.
Matching standard catalog items or engineering customized tripping curves, housing geometries, terminal connections, and auxiliary contact configurations.
Sample production, automated calibration, full type-testing, batch production, and custom private labeling under ISO9001 control.
Export packaging, customs documentation, installation technical guidance, remote commissioning support, and continuous lifecycle warranty management.
See why global energy EPCs, system integrators, and panel builders rely on OFA for their electrical switchgear systems.
"As a system integrator in Poland, we collaborated with OFA on several industrial automation projects. Their product range is remarkably comprehensive, simplifies procurement, and provides consistent high breaking capacity reliability."
Technical Director, System Integration Co. (Poland)
"We deployed OFA's power monitoring devices and DC miniature breakers for our plant retrofit. Installation was simple, and the devices have run continuously without a single false trip for over a year."
Maintenance Manager, Manufacturing Facility (Germany)
"Our commercial PV projects in Chile required robust DC isolation components adapted to dry high-altitude outdoor conditions. OFA's engineering support and fast export delivery exceeded our expectations."
Site Project Engineer, Solar Energy EPC (Chile)
Detailed technical answers to common engineering questions regarding China DC Miniature Circuit Breakers, selection parameters, and operational installation.
Discover additional high-reliability electrical components, miniature isolators, and residual current protection solutions engineered by Wenzhou OFA.
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