Introduction

Electricity is known as a basic necessity of life it is usually generated at power station by national company (EWSA) and distributed to individual uses on a national grid. The grid consists of the over head cables on steel pylon that run across the countryside when the grid reaches a community the distribution is carried on underground and over ground cables to individual plots

The electricity supply company usually brings the service cable from the local distribution net mark into building where it installs the main switch fuse and the meters. The rest of the installation is the responsibility of the contraction and qualified electrician When this mark is completed then the responsibility for maintain the installation transfer to the owner of the building the electricity cheeks that the in circuit are properly installed and lather before the building is officially connected to the main supply this chapter discusses the main principal of electricity installation in a men building as well as simple electrical theory.

The supply in a house pass from the meter to a distribution panel called a consumer unit which you can see in the supply branches inside that the unit to feed several small cables which form the circuit in the consumer unit is protected by a fuse which has fixed value for lights and electrical equipment each unit the consumer unit is protected by a fuse which has a fixed value.

- 5 amps

- 10 amps

- 20 amps

- 30 amps

The fuse value should be matched to the anticipated current in the unit.

Examples:

v Lookers are 30 amps

v Water heater are 15 amps

v Paver sockets on a ring main are 20 amps

v Lighting units are 5 amps

CHAPTER 3: METHODOLOGY

Дата добавления: 2015-07-19