LS Electric Power Factor Correction Panel (APFC)

The LS Electric Power Factor Correction Panel (APFC) is an IEC 61439-2 type-tested assembly engineered for automatic reactive power compensation in industrial, commercial, and utility applications. The design integrates LS Electric product families — Susol and Metasol moulded-case circuit breakers (MCCBs), MC series contactors and capacitor-contactors, and the iS7 variable-frequency drive (VFD) platform — into a compartmentalized APFC layout with busbar and control segregation. Panels are built to IEC 61439-1 general rules and IEC 61439-2 power switchgear assembly requirements; distribution-board and busbar considerations reference IEC 61439-3 and IEC 61439-6 where applicable. Circuit-protection and switching devices comply with IEC 60947; capacitor protection uses fuses meeting IEC 60831. For hazardous-area deployments, enclosures and components are specified in accordance with IEC 60079. Typical APFC configurations use 6–14 capacitor stages with stage contactors sized for high inrush/near-capacitive switching. Heavy-duty capacitor contactors are fitted with pre-charging resistors or pre-insertion resistor (PIR) modules to limit transient currents on capacitor switching. Detuned reactor options (5.67% to 14% reactor impedance) are selected to shift resonance below dominant harmonic orders (commonly detuned for the 5th harmonic at 5.67% or higher for multi-pulse environments) in accordance with harmonic management practices (IEEE 519 / IEC 61000 series). Capacitor banks are protected by dedicated capacitor fuses per IEC 60831 and coordinated with upstream Susol/Metasol MCCBs providing fault-clearing up to the panel’s rated SCCR. APFC panels are normally supplied with internal separation options (Forms 1 through 4b depending on risk and maintenance requirements); Form 4b or segregated busbar compartments are common to isolate capacitor compartments and control wiring, reducing propagation risk for capacitor faults. Panels can be designed for rated currents up to 800 A in standard APFC lineups; when required, busbar systems and Metasol breakers allow factory options up to 2500 A. Short-circuit ratings are engineered and type-tested per IEC 61439-2 with typical SCCR ranges from 10 kA to 50 kA RMS symmetric, and bespoke constructions tested up to higher values on request. Real-world applications include petrochemical and manufacturing plants, large commercial buildings, data centres, mining and marine installations, and renewable-energy plants where reactive-power, harmonic, and transient control are critical. For customers evaluating alternatives, established panel solutions such as Siemens SIVACON, MNS, or Prisma Set are referenced for configuration comparisons; however, LS Electric-based APFCs offer a cost-effective, IEC-compliant option optimized for tight integration with LS drives and control systems.