Explore our premium product selections engineered for commercial solar installations, battery storage (BESS), and industrial automation.
An authoritative technical evaluation of direct current switching challenges, permanent magnet blowout systems, and procurement criteria for international engineering projects.
Unlike Alternating Current (AC) which naturally crosses a zero-voltage point 100 or 120 times per second, Direct Current (DC) maintains a continuous voltage differential. When breaking a 20 Amp DC load under 500V to 1500V conditions, an sustained electric arc forms between contacts. OFA’s 20 Amp DC circuit breakers integrate permanent magnetic blowout chutes that stretch, cool, and extinguish the DC arc in milliseconds.
Global demand for 20A DC circuit breakers is surging due to solar PV string protection, battery energy storage systems (BESS), microgrids, EV fast-charging stations, and telecom base stations. B2B procurement directors prioritize thermal-magnetic tripping stability, bi-directional current flow compliance (IEC 60947-2 Annex P), and modular DIN rail flexibility.
Wenzhou OFA Electrical Technology Co., Ltd. leverages Yueqing’s world-famous low-voltage electrical industrial cluster. By standardizing component stamping, automated silver-point contact welding, and digital testing calibrations, Chinese factories deliver uncompromised quality at highly competitive OEM pricing.
Installing a standard 20A AC circuit breaker in a high-voltage DC solar string will lead to thermal runaway, contact welding, or explosive housing rupture. DC switchgear requires extended contact air gaps, magnetic arc chutes, and non-polarized terminal paths to handle inductance time constants (L/R ratios up to 15ms).
| Electrical Parameter | Standard AC 20A Breaker | OFA Industrial 20A DC Breaker | Engineering Operational Impact |
|---|---|---|---|
| Zero-Crossing Point | Available (50Hz / 60Hz) | None (Continuous DC Voltage) | Requires active magnetic arc driving mechanism |
| Rated Voltage (Un) | 230V / 400V AC | 1P 250V DC / 2P 500V / 4P 1000V-1500V DC | Prevents dielectric breakdown in multi-string PV arrays |
| Ultimate Breaking Capacity (Icu) | 6kA (IEC 60898-1) | 6kA - 10kA (IEC 60947-2) | Safely interrupts high DC fault currents without welding contacts |
| Polarity Design | Non-polarized AC sine wave | Bi-Directional / Non-Polarized Options | Prevents wiring errors in reverse-flow battery charging systems |
| Contact Material | Standard AgCdO / AgNi | High-Density AgSnO2 (Silver Tin Oxide) | Resists electric erosion, arcing pitting, and contact degradation |
Professional, Reliable, and Time-Tested!
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.
Rooted in Yueqing for over a decade, OFA has been providing partners with distribution switchgear and control equipment and supporting products that feature stable performance and cost advantages. We adhere to honest and law-abiding operations, have been rated as tax credit grade A for seven consecutive years, and have earned the long-term trust of numerous clients globally.
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.
Our team has solid experience in the R&D and manufacturing of components for power, energy, industrial automation, and other fields, and can provide flexible solutions for different application scenarios. We never compromise on quality, and have gradually built a reputation as a down-to-earth and responsible electrical manufacturer in the region.
Combining rigorous type-testing, agile customization, and automated production lines to deliver reliable protection switchgear across global markets.
Our technical team continues to delve deep into the R&D and improvement of distribution switchgear and control equipment accessories, equipped with full-process type testing and factory inspection devices for mechanical life, temperature rise, and insulation verification.
Through flexible production that combines standardization and customization, we precisely match customer specification requirements to provide cost-effective configurations backed by a responsive technical support network.
Automated assembly lines and digital inspection stations ensure every step from raw parts to finished circuit breakers remains under strict control, steadily outputting zero-defect products at reasonable costs.
Based on over a decade of industry accumulation and thousands of successful global deliveries, our customer retention rate remains consistently high across Europe, South America, Southeast Asia, and the Middle East.
Our factory adheres to rigorous 100% full-inspection standard SOPs, ensuring that every product meets international certification standards such as CE, IEC, and CCC.
MCCB primary function is to make, carry, and break currents under normal circuit conditions, and to break currents under specified abnormal conditions such as overload and short circuit in high-ampere industrial distribution panels.
At the end of modern low-voltage power distribution systems, the safety and stability of every circuit rely on a reliable guardian — the Miniature Circuit Breaker (MCB), including specialized 20 Amp DC models for DIN rail mounting.
Our Intelligent Air Circuit Breaker (ACB) product line is precisely designed as a high-performance core protection and control device for incoming main power supply panels up to 6300A.
Our Residual Current operated Circuit Breaker (RCCB) product line is a specialized, high-reliability residual fault protection solution designed to prevent electric shocks and earth leakage fires.
RCBO products innovatively integrate three core functions — overload protection, short-circuit protection, and high-sensitivity earth leakage protection — into a single compact DIN rail unit.
The IS Series was born to integrate full isolation capabilities with high-current breaking functionality, providing safe electrical isolation during system maintenance.
Our electrical equipment is designed for diverse operational environments, from simple circuit protection to complex renewable energy system integration across global infrastructure.
Preventing electrical fires and shock hazards in residential consumer units and smart distribution boxes.
Reliable main and branch circuit power distribution for office towers, shopping malls, and hotels.
Protecting PLC units, motor drives, variable frequency drives (VFDs), and robotic control panels.
20A DC string circuit protection for rooftop PV solar arrays, combiner boxes, and grid-tie inverters.
Safe isolation and overcurrent tripping for Lithium-ion battery racks and off-grid power storage.
High-reliability dual-bus power supply isolation for server racks, UPS systems, and HVAC units.
DC circuit protection for high-power DC fast chargers (DCFC) delivering rapid electric vehicle charging.
Integrated micro-breakers supporting remote telemetry, energy monitoring, and automatic resetting.
Robust switchgear deployed in street lighting control cabinets, water treatment plants, and rail transit.
See why global industry leaders rely on OFA for their electrical switchgear and control 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 and 20A DC breakers to upgrade the power distribution system in our workshop. The installation and setup were simpler than expected, and integration went smoothly. Most importantly, they have been running very stably for over a year."
"Deploying OFA's energy efficiency management system for several office buildings we manage was a wise decision. The system helped us gain detailed insights into electricity usage in different areas and achieve energy savings through optimized operational strategies."
"Our PV project required reliable DC switchgear 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 during the initial phase."
From initial requirement alignment to lab simulation, joint engineering development, and agile batch delivery.
Core Needs: Proven solutions, rapid implementation, clear ROI, easy maintenance (PV grid integration, building energy retrofits).
Core Needs: High-reliability design with redundancy, seamless integration, sustainable operational support.
Expert engineering answers regarding 20 Amp DC circuit breaker selection, OEM customization, and global shipping policies.
Complete your power distribution system with our extensive product catalog below.
Contact OFA's technical and sales team immediately to discuss your next power distribution or solar energy project. Standard samples and engineering drawings are available upon request.
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