Mains, electricity

• Three core cable


  Cable used to connect appliances to mains electricity, has three wires
• Live wire


  • Carries potential difference of around 230 volts
  • Connected to fuse in plug
• Neutral wire


  • Completes the circuit with live wire
  • Has potential difference of around 0 volts compared to live wire
• Earth wire


  • Safety wire
  • Connected to metal case of appliance
  • Connected to ground with metal rod
• Function of earth wire

  1. If live wire comes loose and metal case becomes live, earth wire provides a path for large current to flow to ground

  2. Fuse melts and shuts off current, preventing electric shock
• Mains electricity in UK is alternating current (AC) with frequency of 50 Hertz and potential difference of around 230 volts
• Live wire can be extremely dangerous and fatal if touched, even with switch open as part of live wire still has 230 volts
• Earth wire prevents electric shock by providing a path to ground if metal case becomes live