Mains Electricity

• Three core cable


  Cable used to connect appliances to mains electricity
• Wires in three core cable

  • Live wire
  • Neutral wire
  • Earth wire
• Live wire


  Carries potential difference of around 230 volts from the supply
• Neutral wire


  Completes the circuit with the live wire, has a potential difference of around 0 volts
• Earth wire


  Safety wire, connected to the ground
• Function of earth wire

  If live wire comes loose and touches metal case, current flows to earth, fuse melts and shuts off current, preventing electric shock
• Live wire can be extremely dangerous and fatal if touched, even if switch is open
• Potential difference of earth is 0 volts
• Most appliances in the UK are connected to an earth wire
• Appliances with metal cases can be dangerous if live wire touches case, making case live