Page 930 - Basic Electrical Engineering

consumer’s main switch-fuse is connected after the meter. From here the
supply is fed to the distribution fuse board through a busbar and neutral link.
It is to be noted that all fuses should be placed only in the live or phase

wire and not in the neutral wire. All switches should be connected on the live
lines and not on the neutral line.

13.9.4 Neutral and Earth Wire

The neutral wire is taken out from the star point of the secondary of the
distribution transformer. The star point is earthed. The lines are taken out

from the terminals R, Y, B of the three-phase windings and the neutral point
N. Each phase wire and the neutral wire constitutes single-phase supply.

In addition to the four wires taken out from R, Y, B, and N terminals, a
fifth wire, called earth wire is provided. The earth wire is provided for the

purpose of protection of persons using electrical appliances. In case of any
leakage in the system, the persons using any equipment will not get any

electric shock if the body of all electrical appliances are connected to the
earth terminal.

Figure 13.11 Layout of distribution board for single-phase installation

The neutral wire is connected to the neutral point of the transformer which

is earthed at the substation itself. The earth wire starts at a solid earthing