BY81JS/450-20+15 Series Smart PFI Capacitors With Built-in MCB, LCD & Controller. Auto-Power Factor Improvement Capacitor

Model Meaning

Main Specifications of BY81JS/450-20+15 Series Smart Capacitor

Introduction of BY81JS/450-20+15 Series Smart Capacitor

The BY81JS/450-20+15 Series Smart PFI Capacitors are engineered as a cutting-edge low-voltage power capacitor solution for optimizing electrical power quality in 3-phase power systems. Designed for low-voltage electrical networks (up to 450V), this 3-phase capacitorintegrates a built-in MCB (Miniature Circuit Breaker), high-resolution LCD interface, and a DSP-based controller to deliver automatic power factor correction (targeting PF ≥0.98). By dynamically compensating reactive power deficits in real time, it reduces line losses by up to 30% and stabilizes 3-phase voltage imbalances with >90% efficiency, critical for industrial motors, HVAC systems, and data centers. The low-voltage device employs self-healing metallized polypropylene film technology, ensuring durability under harmonic-rich environments (THDi <3%) and compliance with IEEE 519-2022 standards for harmonic mitigation. Its modular design supports seamless scalability in low-voltage power capacitor compensation systems, enabling adaptive adjustments for fluctuating loads in manufacturing plants or renewable energy grids.
The capacitor’s IoT-ready RS-485/Modbus interface facilitates remote monitoring of 3-phase electric parameters, including voltage, current, and harmonic distortion levels, via centralized energy management platforms. The integrated LCD provides real-time diagnostics, displaying low power voltage fluctuations, capacitor health status, and fault alerts (e.g., overvoltage, overheating). Built to withstand extreme conditions (-25°C to +55°C), the low-voltage equipmentfeatures corrosion-resistant copper-nickel terminals and IP54-rated enclosures, ideal for harsh environments like mining sites or coastal solar farms. As a 3-phase power capacitor, it also incorporates MOV (Metal Oxide Varistor) surge protection, safeguarding connected electrical equipment from transient voltages up to 6kV.

Applications & Certifications for Reliable Performance
Certified to UL 810, IEC 60831-1, and GB/T 22582, the BY81JS/450-20+15 Series excels in low-voltage electrical applications requiring power low voltage stability and three-phase electricbalance. It is widely deployed in automotive factories to neutralize harmonics from robotic arms, in hospitals to prevent 3-phase power voltage sags affecting MRI machines, and in solar farms to stabilize grids against inverter-induced fluctuations. The capacitor low voltage design minimizes reactive power penalties by up to 25%, while its low power electricity consumption (<2W standby) aligns with global energy efficiency initiatives.
The 3-phase power capacitor also addresses electrical power quality challenges in commercial complexes, where LED lighting and elevators cause 3-phase imbalance. Its active filtering algorithms suppress harmonics up to the 50th order, while the MCB ensures fail-safe disconnection during faults. For low-voltage device installations, the tool-free terminal clamps reduce wiring time by 40%, and the asymmetric honeycomb ventilation slots enhance thermal dissipation, preventing hotspots even at 100% load. Compatible with smart grid protocols, this electric capacitor supports predictive maintenance via cloud analytics, slashing downtime by 50% in mission-critical electrical equipment like semiconductor fabs.

Working Principle of the BY81JS/450-20+15 Series Smart Capacitor

BY81JS/450-20+20 series smart capacitor is a dynamic reactive power compensation and harmonic suppression solution designed for low voltage power systems. The core of the device integrates a high-speed DSP (digital signal processor) controller that continuously monitors grid parameters, including voltage, current, phase angle, and harmonic distortion. By analyzing real-time data from the three-phase power system, the controller can identify reactive power gaps, voltage imbalances, and harmonic frequencies (up to 50 times). The system uses self-healing metallized polypropylene film capacitors to dynamically adjust the capacitive reactance to inject or absorb reactive power, achieve near-instantaneous power factor correction (target power factor ≥ 0.98), and stabilize the grid voltage within ±1% of the rated voltage.

In terms of harmonic management, the capacitor adopts a hybrid approach: passive filtering through tuned reactors to suppress low-order harmonics (3rd, 5th, 7th), while the digital signal processor (DSP) activates an active harmonic elimination algorithm to neutralize high-order harmonic distortion caused by non-linear loads such as variable frequency drives (VFDs) and LED drivers. At the same time, its three-phase unbalance correction function uses modular capacitor banks to redistribute reactive power between phases, thereby reducing neutral current imbalance by up to 90%. The IoT-enabled communication interface (RS-485/Modbus) can be seamlessly integrated with energy management systems, allowing remote adjustments based on load fluctuations or predictive analysis.The device is optimized for low voltage power capacitor compensation systems, and its forced air cooling design ensures thermal stability at 450A continuous operation, while corrosion-resistant terminals maintain a contact resistance of <0.1mΩ, minimizing energy losses. The BY81JS/450-20+20 series optimizes power quality by coordinating adaptive control logic with powerful hardware, thereby reducing energy costs by 25% for industrial plants, renewable energy power plants, and commercial complexes.

Main Functions of BY81JS/450-20+15 Series Smart Capacitor

1.Dynamic reactive power compensation
Automatically adjusts capacitive reactance to correct lagging power factor (PF ≥ 0.98) in low voltage power capacitor compensation systems, reducing line losses by up to 30% and complying with IEC 61921 standards for industrial and commercial power grids.
2. Active harmonic suppression (3rd to 50th order)
A passive LC filter and active DSP algorithm are combined to suppress harmonic distortion (THDi <3%), ensuring compliance with IEEE 519-2022 requirements for harmonic management in VFD, solar inverter and UPS system environments.
3. Real-time three-phase unbalance correction
Phase currents are monitored via three-phase smart capacitor logic, dynamically redistributing reactive power to eliminate imbalance (efficiency >90%), which is critical for motor drive systems and data center power distribution.
4. Voltage stabilization and surge protection
Maintains voltage levels within ±1% of nominal value, mitigating voltage sags/swells caused by sudden load changes. Integrated MOV (Metal Oxide Varistor) technology protects against transient overvoltages (up to 6kV) in power quality sensitive applications.
5. IoT remote monitoring and control
Features RS-485/Modbus and cloud-compatible interfaces for real-time data tracking, predictive maintenance alerts, and firmware updates to optimize smart capacitor performance in smart grids and microgrids.
6. Self-diagnosis and fault isolation
Embedded sensors detect capacitor aging, overheating or internal faults, triggering automatic bypass to ensure uninterrupted operation of the low-voltage distribution network.

Terminal Diagram of BY81JS/450-20+15 Series Smart Capacitor

 Product Size Information