Electrical safety

1 State the hazards of:

(a) damaged insulation

(b) overheating cables

(c) damp conditions

(d) excess current from overloading of plugs, extension leads, single and multiple sockets when using a mains supply

2 Know that a mains circuit consists of a live wire (line wire), a neutral wire and an earth wire and explain why a switch must be connected to the live wire for the circuit to be switched off safely

3 Explain the use and operation of trip switches and fuses and choose appropriate fuse ratings and trip switch settings

4 Explain why the outer casing of an electrical appliance must be either non-conducting (double-insulated) or earthed

5 State that a fuse without an earth wire protects the circuit and the cabling for a double-insulated appliance