Paper 2 - Electrical Uses PAPER 2 Electrical Uses UNIT 8 Protective Devices in Domestic Wiring Protective Devices in Domestic Wiring Principle/Working MechanismProtective devices safeguard electrical systems by:Overcurrent Protection (Fuses/MCBs)Earth Leakage Protection (RCCBs/ELCBs)Surge Protection (Lightning arresters)Working Principles:Thermal-Magnetic Trip (MCBs)Residual Current Detection (RCCBs)Voltage Diversion (Arresters) Types/Classifications Overcurrent ProtectionDeviceTrip MechanismCurrent RangeSymbolRewirable FuseMelting wire5A-100A MCBThermal + Magnetic6A-63A MCCBAdjustable trip10A-800A Earth Leakage ProtectionDeviceSensitivityResponse TimeELCB30mA-300mA<300msRCCB10mA-300mA<200ms Surge ProtectionTypeApplicationVoltage RatingClass...
