Explore our flagship direct-current (DC) molded case circuit breakers, miniature circuit breakers (MCB), and specialized residual current devices engineered for industrial, solar PV, and commercial distribution boards.
Modern low-voltage power distribution systems operate under increasingly complex conditions. The rapid global integration of renewable energy sources—specifically photovoltaic (PV) generation, battery energy storage systems (BESS), and electric vehicle (EV) charging stations—has introduced stringent operational demands on switching and protective devices. The OF1 Series Molded Case Circuit Breaker (MCCB) and Miniature Circuit Breaker (MCB) platform, designed and manufactured by Wenzhou OFA Electrical Technology Co., Ltd., represents a benchmark synthesis of advanced arc-quenching physics, optimized thermal-magnetic trip units, and robust mechanical contact design.
Key Engineering Insight: Direct Current (DC) interruption presents unique physical challenges compared to Alternating Current (AC). Lacking a natural current zero-crossing point every half-cycle, DC arcs persist with continuous thermal energy. The OF1-125/PV and OF1-250/PV series utilize elongated multi-grid arc chute runners paired with permanent magnetic blowouts to force arcs into cooling chambers within milliseconds.
The core architecture of the OF1 Series incorporates a high-dielectric BMC (Bulk Molding Compound) enclosure capable of enduring high thermal stress and mechanical shocks up to 50g. When a short-circuit fault occurs, the internal silver-alloy contacts (AgNi or AgSnO2) separate at ultra-high speed driven by a pre-stressed spring storage mechanism.
Simultaneously, the induced electromagnetic field drives the arc along copper-plated splitter plates. The arc grid divides the main arc voltage into multiple series micro-arcs, rapidly increasing the overall arc voltage above the system supply voltage ($V_{arc} > V_{sys}$), forcing rapid extinction. This limits the specific let-through energy ($I^2t$), preventing thermal degradation of downstream conductors and transformer insulation.
| Parameter / Model | OF1-125/PV DC MCCB | OF1-250/PV DC MCCB | BA88-630E MCCB | OFD4Z7 / OFL8 MCB |
|---|---|---|---|---|
| Rated Operational Voltage (Ue) | DC 500V / 800V / 1000V | DC 1000V / 1500V | AC 400V / 690V | AC 230V / 400V (DC 250V/P) |
| Rated Current Range (In) | 16A to 125A | 125A to 250A | 250A to 630A | 1A to 63A |
| Ultimate Short-Circuit Breaking Capacity (Icu) | 20 kA at 1000V DC | 25 kA at 1000V DC | 50 kA / 65 kA | 6 kA / 10 kA |
| Service Short-Circuit Breaking Capacity (Ics) | 100% Icu | 100% Icu | 75% - 100% Icu | 75% Icu |
| Trip Unit Technology | Thermal-Magnetic Fixed/Adjustable | Adjustable Thermal-Magnetic / Microprocessor | Electronic Microprocessor (LSI) | Fixed B, C, D Characteristics |
| Standard Compliance | IEC 60947-2, GB/T 14048.2 | IEC 60947-2, EN 60947-2 | IEC 60947-2, CE, CCC | IEC 60898-1, IEC 60947-2 |
| Mechanical / Electrical Endurance | 8,500 / 1,500 ops | 10,000 / 2,000 ops | 15,000 / 4,000 ops | 20,000 / 10,000 ops |
Wenzhou OFA Electrical Technology Co., Ltd. delivers customized power distribution architecture across crucial infrastructure sectors globally.
In centralized and string PV installations, operating voltages frequently exceed 1000V DC. The OF1-125/PV and OF1-250/PV breakers are specially designed for DC combiner boxes and inverter DC input side protection, preventing reverse-current faults and overloads under high ambient operating temperatures up to 70°C.
Lithium-ion battery racks exhibit extremely low internal impedance, generating severe short-circuit prospective currents during catastrophic breakdown. OFA DC molded case circuit breakers provide instantaneous magnetic protection calibrated to trip within milliseconds, protecting battery cells and power conversion systems (PCS).
Unplanned manufacturing downtime costs thousands of dollars per hour. OFA’s air circuit breakers (ACB OFW1 series) and electronic MCCBs (BA88 series) integrate remote status signaling, shunt tripping, and undervoltage release modules for seamless integration into Programmable Logic Controller (PLC) systems.
Safety in modern high-rise buildings demands reliable life protection. Our OFID, OFR1, and OFC Residual Current Circuit Breakers (RCCB/RCBO) combine ground fault leakage detection (30mA human safety sensitivity) with short-circuit protection, reducing panel space footprint by up to 50%.
Hyperscale data centers require dual-path power redundancy (A+B feeds). OFA isolator switches (OFIS series) and intelligent ACBs ensure instantaneous automatic transfer switch (ATS) operation without disrupting zero-phase server power supplies.
Ultra-fast DC chargers operating up to 400kW require high-capacity isolation and overcurrent protection. The OFBLT high-performance DC breaker family guarantees reliable fault isolation under continuous harmonic stresses.
Wenzhou OFA Electrical Technology Co., Ltd. is continuously expanding R&D investments into solid-state protection, IoT telemetry, and eco-friendly manufacturing materials.
Integration of RS485 Modbus-RTU and wireless Matter/Zigbee communications directly into DIN-rail MCBs and MCCBs. Real-time monitoring of contact temperature, insulation resistance, voltage sag, and power factor enables predictive maintenance before thermal breakdown occurs.
Development of hybrid solid-state topologies combining wide-bandgap SiC (Silicon Carbide) power MOSFETs with mechanical isolation. This technology reduces fault interruption times from milliseconds down to sub-microseconds (<10 µs), completely eliminating physical arcing.
Complete phase-out of halogenated flame retardants and heavy metals in favor of bio-based high-temperature thermoplastics and 100% recyclable copper/silver alloys, aligning with European Union RoHS 3 and REACH directives.
Rooted in Yueqing, Wenzhou—the Capital of Electrical Appliances in China—Wenzhou OFA Electrical Technology Co., Ltd. combines geographic industrial cluster advantages with modern Industry 4.0 smart plant infrastructure.
Our automated production floor features high-precision stamping, automated silver contact welding, robotic calibrated coil winding, and digital CCD visual inspection systems. Every single piece of equipment undergoes rigorous 100% full-inspection SOP routines covering instant trip calibration, dielectric voltage resistance, and contact resistance checks before final packaging.
Tax Integrity & Corporate Reliability: Rated as a Tax Credit Grade A Enterprise for 7 consecutive years, OFA provides global enterprise buyers with total contractual security, transparent customs documentation, and seamless order fulfillment.
How international EPC contractors, panel builders, and OEM brands collaborate with OFA for custom breaker configurations.
Our engineering team reviews project single-line diagrams (SLD), short-circuit calculation sheets, and enclosure dimensions to recommend optimal trip curves (B, C, D, K, Z) and breaking capacity ratings.
We offer bespoke laser engraving, customized casing colors, private label packaging, special rated voltages (e.g., 60Hz North American or 400Hz defense frequencies), and pre-wired auxiliary contacts.
Using flexible lean manufacturing cells, prototype samples can be produced and dispatch-tested within 5 to 7 working days, drastically accelerating customer time-to-market.
From massive power mains down to residential terminal distribution, OFA manufactures complete low-voltage circuit protection suites.
Series: BA88 Electronic, DCM1, DCOF1, OFM1, OFBLT, OF1, OFA-M1. Up to 1600A frame sizes. Engineered for power distribution feeders, motor protection, and high-voltage DC solar strings.
Series: OF6KA, OF10KA C65, OFAFT, OFD4Z7, OFDL, OFDP, OFDZ47, OFEU, OFKL, OFKL-NXB, OFL7, OFL8, OFNC, OFPF, OFP. DIN-rail mounting from 1P to 4P, 1A to 125A.
Series: OFW1 Intelligent Universal Circuit Breaker. Frame currents up to 6300A. Integrated intelligent controller with communication bus, selective short-time protection, and harmonic analysis.
Series: OFAP6-AC, OFDPN, OFDX, OFGX, OFID, OFL7, OFPM. High sensitivity ground leakage protection detecting AC and pulsating DC residual currents (Type AC, Type A, Type B).
Series: OFC, OFKL-80A, NB1L, OFMIN, OFOM, OFR1. All-in-one overload, short-circuit, and earth leakage protection in compact 1P+N or 3P+N modules.
Series: OFIS-125A, OFIS-BH, OFIS-DS. High-capacity load break isolators providing reliable contact separation distance for safe system maintenance operations.
"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."
— Andrzej Nowak, Technical Director (Poland)
"We purchased OFA's intelligent power monitoring devices and MCCBs to upgrade the power distribution system in our old 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."
— Markus Weber, Maintenance Manager (Germany)
"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."
— Priya Sharma, Facilities Supervisor (Bangkok, Thailand)
"Our PV project required reliable communication management and DC protection equipment. OFA's OF1-PV DC circuit breakers met our core needs at a reasonable price and could adapt to our local outdoor environment. Their engineers provided excellent configuration guidance via email and video calls during the initial phase."
— Carlos Rivera, Site Engineer (Chile)
Clear engineering answers regarding the OF1 series, procurement logistics, OEM customization, and standard compliance.
Browse our additional catalog of precision-engineered molded case, miniature, and specialized high-breaking circuit breakers.
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