CHAPTER 3: BASIC PROTECTION AND SWITCHING EQUIPMENTS GENERATION Generator Turbine Transformer Generator TRANSMISSION EHV (Extra High Voltage) – 275 kV & 500 kV Subtransmission – 66 kV and 132 kV Transmission Line DISTRIBUTION – 11 kV , 22kV & 33 kV LOAD Consumer (factory and residency) CHARACTERISTIC NEEDED FOR SWITCH GEAR Realiability Selectivity High speed Sensivity Cost SWITCH GEAR EQUIPMENT 1.) Fuse When a fuse blows out, it takes quite sometimes to replace it and restore supply to the customers. A fuse cannot successfully interrupt heavy fault currents that result from faults on modern high voltage and large capacity circuits. limited to low-voltage and small capacity circuits 3 types of fuses; cartridge, rewired, high rate capacitance 2.) Circuit Breaker Suitable for high capacity circuits. Can make or break a circuit either manually or automatically under all condition. ARC PHENOME