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14 Electrical Earthing And Bonding Of Building Services


The requirements for electrical earthing and bonding of building services are given in BS 7671: 2001 ā€” Requirements for electrical installations, also known as the IEE Wiring Regulations.

The requirements for the different types of supply TN-C-S, TN-S and TT are all slightly different. The guidance given here is based on the requirements for a TN-C-S (or PME) supply. This is because new supplies are almost exclusively PME and the requirements for PME supplies are the most onerous. Compliance with the bonding requirements for a PME supply will result in compliance with requirements for TN-S and TT systems.

All incoming service pipes (gas, oil and water) and internal pipework (hot, cold, central heating) may now be of plastic. Guidance is given in this section on the requirements for the earthing and bonding of such installations as well as for metal services.

Compiled and published by: The Institute of Plumbing
  Last revision: 2002
  Edition: 1
  Number of pages: 6
  Format: PDF