mains electricity

• Mains electricity in the UK

  Alternating current (AC) with a frequency of 50 Hertz and a potential difference of around 230 volts
• Appliances connected to mains electricity

  • Using three core cable
• Live wire


  Brown wire, carries a potential difference of around 230 volts, connected to a fuse in the plug
• Neutral wire


  Blue wire, completes the circuit with the live wire, potential difference around 0 volts compared to live wire
• Earth wire


  Green and yellow striped wire, a safety wire connected to the ground
• Live wire is dangerous

  Can be fatal if touched, even if the switch is open as the first part of the live wire still has 230 volts
• Metal-cased appliances


  Can become live if the live wire comes loose, causing a fatal electric shock
• Earth wire function


  Connects the metal case to the ground, so if the case becomes live, a large current flows to the earth, causing the fuse to melt and shut off the current, preventing electric shock