16th Edition (reference only) – NOW superseded by the 17th Edition IEE Regulations.

chapter 5

chapter 6

  5.1 - The earthing principle 5.6 - Protective multiple earthing (PME)
  5.2 - Earthing Systems 5.7 - Earthed concentric wiring
  5.3 - Earth fault loop impedance 5.8 - Other protection methods
5.4 - Protective conductors 5.9 - Residual current devices (RCDs)
5.5 - Earth electrodes

5.10 - Combined functional and protective

5.5.1 -  Why must we have earth electrodes?

The principle of earthing is to consider the general mass of earth as a reference (zero) potential. Thus, everything connected directly to it will be at this zero potential, or above it by the amount of the volt drop in the connection system (for example, the volt drop in a protective conductor carrying fault current). The purpose of the earth electrode is to connect to the general mass of earth.

With the increasing use of underground supplies and of protective multiple earthing (PME) it is becoming more common for the consumer to be provided with an earth terminal rather than having to make contact with earth using an earth electrode.


Return to top of page

Extracted from The Electricians Guide Fifth Edition
by John Whitfield

Published by EPA Press Click Here to order your Copy.

Click here for list of abbreviations