Precision-engineered circuit protection devices customized for Bangladeshi manufacturing facilities, commercial distribution boards, and heavy industrial load setups.
Bangladesh has transformed into one of Asia's most dynamic manufacturing hubs. As industrial power density soars, traditional protective gear fails under local environmental stress. The NB1L Series RCBO architecture bridges critical compliance gaps.
Bangladesh’s rapid economic evolution—propelled by the Ready-Made Garments (RMG) industry, mega-infrastructure projects like Bangabandhu Sheikh Mujib Shilpa Nagar (BSMSN), and extensive commercial urban development in Dhaka and Chittagong—has placed unprecedented demands on low-voltage power distribution networks.
Operating low-voltage switchgear in Bangladesh entails overcoming extreme environmental and operational hurdles:
Conventional setups utilizing independent MCB and RCCB units consume double the DIN-rail space and introduce multiple wiring interconnections that increase thermal failure points. The NB1L Series 1P+N / 2P RCBO integrates overcurrent, short-circuit, and high-sensitivity earth-leakage protection into a unified 18mm module, eliminating wiring vulnerability while complying with IEC/EN 61009-1 standards.
Designed for extreme durability, the NB1L Series integrates high-grade internal materials with cutting-edge electromagnetic trip mechanisms.
| Technical Specification | NB1L Series 1P+N RCBO | NB1L Series 2P Residual Current Breaker | OFAFT / OFL7 Series MCB |
|---|---|---|---|
| Standard Compliance | IEC/EN 61009-1, GB 16917.1 | IEC/EN 61009-1, IEC 60755 | IEC/EN 60898-1, IEC 60947-2 |
| Rated Current (In) | 6A, 10A, 16A, 20A, 25A, 32A, 40A | 16A, 25A, 32A, 40A, 50A, 63A | 1A, 3A, 6A, 10A, 16A, 20A, 32A, 40A, 63A |
| Residual Current Type | Type AC (Standard), Type A (Pulsating DC) | Type AC, Type A, Type F | N/A (Overload & Short Circuit Only) |
| Rated Sensitivity (IΔn) | 30mA (Life Protection), 100mA, 300mA | 30mA, 100mA, 300mA | N/A |
| Short-Circuit Breaking (Icn) | 6,000A (6kA) / 10,000A (10kA) | 6,000A (6kA) / 10,000A (10kA) | 6,000A / 10,000A / 15,000A |
| Tripping Curve Options | B Curve (3-5In), C Curve (5-10In) | B Curve, C Curve, D Curve (10-14In) | B, C, D Curves Available |
| Housing Flame Retardancy | UL94 V-0 Self-Extinguishing PA66 | UL94 V-0 Thermoplastic Shell | UL94 V-0 Flame Retardant Polymer |
| Electrical / Mechanical Life | 10,000 Operations / 20,000 Operations | 10,000 Operations / 20,000 Operations | 10,000 Operations / 20,000 Operations |
Constructed with 12 arc-runner plates that rapidly divide and cool electric arcs during short-circuit faults, preventing contact welding and prolonging internal component lifespan.
Utilizes AgCdO/AgSnO2 contact points offering micro-level contact resistance. This minimizes internal temperature rise during high ambient operations in Bangladeshi factories.
Engineered with a two-position bistable locking clip allowing swift mounting and unmounting from standard 35mm DIN-rails without disturbing adjacent circuit breakers.
From ready-made garment complexes in Gazipur to high-rise commercial hubs in Gulshan, OFA's NB1L Series delivers field-tested performance under demanding real-world conditions.
Industrial facilities in Narayanganj, Gazipur, and the Chittagong EPZ operate hundreds of automated sewing machines, heavy dyeing vats, and high-capacity air handling units. High humidity and continuous vibration often induce nuisance trips in lower-tier breakers.
NB1L Type A 30mA RCBOs withstand high harmonic distortion caused by variable frequency drives (VFDs) while fulfilling RSC audit criteria for human life safety and fire protection.
Dhaka’s high-density commercial towers in Gulshan, Banani, and Motijheel require compact distribution boards where space commands a premium. Traditional 2-module breaker units severely limit circuit capacity.
The ultra-compact 1P+N NB1L RCBO cuts enclosure space consumption by 50%, enabling panel builders to double outgoing protection channels without upgrading DB box dimensions.
Net Metering policies in Bangladesh have spurred widespread rooftop solar installations across industrial plants seeking LEED green building certifications.
NB1L residual current breakers offer bi-directional current protection and robust immunity against high-frequency DC ripple leakage coming from solar inverters.
Remote BTS tower sites across rural Bangladesh (operated by Grameenphone, Robi, Teletalk) experience frequent lightning strikes and line surges.
Integrating NB1L RCBOs with high surge-withstand capability safeguards sensitive telecom rectifiers while allowing seamless auto-recloser module integration.
Transitioning Low-Voltage Distribution from Passive Protection to AI-Enabled Predictive Electrical Safety.
Embedding RS485 / Modbus RTU communication chips inside the NB1L frame to deliver real-time telemetry on leakage currents (mA), operating temperature (°C), line voltage, and load current directly to factory SCADA systems.
Extending Type B residual protection capabilities to handle smooth DC leakage currents generated by EV fast-charging stations, three-phase VFDs, and battery energy storage systems (BESS) being deployed across Bangladesh.
Incorporating Arc Fault Detection Device (AFDD) microprocessors into the NB1L footprint to analyze high-frequency arcing signatures, virtually eliminating electrical fire risks in aging industrial wiring installations.
Direct Sourcing from Yueqing, Wenzhou—The World's Largest Low-Voltage Electrical Appliance Manufacturing Cluster.
Founded in 2013 in Yueqing, Wenzhou, Wenzhou OFA Electrical Technology Co., Ltd. has established itself as an authoritative manufacturer and exporter of distribution switchgear, control equipment, and circuit protection components. Holding a Tax Credit Grade A rating for seven consecutive years, OFA combines strict quality control with lean manufacturing efficiency.
For importers, EPC contractors, and electrical wholesalers in Bangladesh (Dhaka, Chittagong, Sylhet), sourcing directly from OFA offers decisive competitive advantages:
We support Bangladeshi local brands and panel builders with extensive customization options:
Meeting international IEC benchmarks and local BSTI / RSC audit guidelines.
The global benchmark governing Residual Current Operated Circuit Breakers with Integral Overcurrent Protection (RCBOs). OFA’s NB1L Series passes rigorous type-tests including 10kA short-circuit duty cycles and surge voltage withstand test up to 4kV.
Products supplied to Bangladesh comply fully with Bangladesh Standards and Testing Institution (BSTI) regulations, supplied alongside Certificate of Origin (CO), Form E/CO documentation, and clean bill of lading for rapid Chittagong port clearance.
Designed to pass rigorous electrical safety audits conducted by the RMG Sustainability Council (RSC). Our 30mA high-sensitivity models guarantee compliant earth fault isolation across modern garment processing lines.
Explore our full line of MCBs, RCCBs, MCCBs, and Isolators for Bangladesh industrial projects.
Rooted in Yueqing, Wenzhou—the Capital of Electrical Appliances in China—Wenzhou OFA Electrical Technology Co., Ltd. (Founded 2013) is a premier technology enterprise specializing in low-voltage distribution switchgear, control equipment, and energy management solutions.
With an experienced R&D team and state-of-the-art automated manufacturing infrastructure, OFA serves global clients across industrial automation, renewable power, commercial real estate, and utility distribution networks. Rated as Tax Credit Grade A for seven consecutive years, we maintain non-negotiable quality control standards across all assembly lines.
Technical and commercial clarity for Bangladeshi importers, panel builders, and EPC engineers.
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