LV Distribution

This chapter introduces the following elements used to define the Low Voltage power distribution:

• the earthing schemes (TN, TT, IT) and their characteristics
• the different types of distribution equipment: switchboards, cables, and busways (busbar trunking systems)
• and the list of external influences defined by the IEC 60364-5-51

Chapter E - Contents

• Earthing schemes
  • Earthing connections
  • Definition of standardised earthing schemes
  • Characteristics of TT, TN and IT systems
  • Selection criteria for the TT, TN and IT systems
  • Choice of earthing method - implementation
  • Installation and measurements of earth electrodes
• The installation system
  • Distribution switchboards
  • Cables and busways
  • Harmonic currents in the selection of busbar trunking systems (busways)
• External influences (IEC 60364-5-51)
  • Definition and reference standards
  • Classification
  • List of external influences
  • Protection provided for enclosed equipment: codes IP and IK