Page 932 - Basic Electrical Engineering

Earth electrode

Places where there is a network of underground cables, the earth terminal is
obtained by making connections with the lead sheath or steel armour of the

underground cable. The lead sheath or the steel armour of the cable will serve
as the earth electrode. However, where such underground cable is not

available, earth electrodes are laid on the ground to get the earth terminal. To
avoid corrosion, the material chosen for the earth electrode, either a pipe or a
plate, should be made of copper or zinc-coated iron. Typical installation of

two types of electrodes, viz the rod or pipe electrode and plate electrode are
made. A rod-type electrode has been shown in Fig. 13.13.

Figure 13.12 Shows the use of earth wire as an essential requirement to protect against electric shock