Main Components of Capacitor Banks Explained | Medium & Low Voltage Power Factor Correction

In this lecture, we explore the main components of capacitor banks and explain the function of each part in both medium-voltage and low-voltage systems. We start by clarifying the difference between a capacitor unit and a capacitor bank, and why multiple units must be combined to provide the required reactive power (kVARs) for power factor correction. Using both single-line diagrams and practical photos, we cover the essential components of a capacitor bank, including: Main cables & busbars – for power supply distribution. Surge arresters – for protection against overvoltage. Isolating & earth switches – for safety during maintenance. Regulator – for automatic power factor control. Contactors – for switching capacitor stages in and out. Series reactors (inrush current coils) – for limiting inrush current and preventing resonance. Capacitor units – the core elements providing reactive power. Current transformers (CTs) – for unbalanced current detection. Fuses (in LV banks) – for protection against short circuits. By the end of this session, you will have a complete understanding of how capacitor banks work, how their components are arranged in star or delta configurations, and how they automatically respond to variations in load to maintain a healthy power factor. This lecture is valuable for engineers, technicians, and students who want to understand the practical operation of capacitor banks in electrical power systems.