Electrical Installation

Electrical hazards are a major cause of death and serious injury on construction
sites. This industry standard provides practical guidance to employers,
designers, manufacturers, importers, suppliers (including hirers), electrical
contractors and electricians on eliminating or reducing the risk of electrocution
and electric shock to any person.
Planning is the most important factor before commencing any electrical work
procedure. The design and planning should take into consideration, the prevailing
conditions at the site and the requirements of the consumers. Before starting the
project, electrical drawings should be prepared along with all working drawings.
Planning at the initial stages will help to decide the locations of each point in each
room, specification of materials, required load for each flat, and each building.
By planning in the initial stages and preparing the drawings accordingly, chances
of mistakes by an engineer are reduced considerably. This means the repetition of
work is avoided. This results in the economy of electrification work.
POSITIONS AND REQUIREMENTS OF ELECTRICAL POINTS
1. Fan points should be diagonally in the center of the room, excluding the
loft width.
2. Switchboards should be nearest to the entrance, opposite the door
opening.
3. Switches for the bathroom should be outside the door.
4. Consider the probable furniture arrangement, before deciding the
switchboard and light points in the rooms.
5. PowerPoint in the kitchen should be nearest to the kitchen platform. The
minimum requirement of electrical points is given in the table.
EARTHING
1. Earthing is the term used for the electrical connection to the general mass of
earth.
2. There are various methods of earthing but the most common method is earthing
by plate electrodes.
3. Plate electrodes are made of copper or galvanized iron.
4. The size of the copper plate shall not be less than 600mm x 600mm x 3.15mm
and the thickness of the iron plate should not be less than 6.30mm.
5. Earthing plate should be placed vertically, on its edge.

6. The top edge of the plate should not be less than 1.5m below the surface of the
ground.
7. The resistance of the earth electrodes depends upon the resistance of the soil.