House Wiring System and Some Electrical Devices

House wiring system

Electricity is produced from the electric power house. In Nepal, the electricity distributed comes in two wires one live (also called phase) wire and another neutral. The live wire acts as a positive terminal and neutral wire act as a negative terminal. Both the wires are connected to a meter box to our home, also the live wire has fuse associated with it. All the current flowing in our home flows through it. Normal capacity of that fuse is 15A, but it can be increased or decreased according to the household needs. Then from another side of the meter box both (live and neutral wires) are taken out. Those lines are taken into a switch box from where lines for different rooms are panned out. The switch box also has its own fuse for each line is taken out from it, that regulates current going into each room or distribution board. If distribution board is used then the individual lines to the room are distributed from here. In our home, along with live and neutral wires the earthing wire is also added.

Earthing is a system where excessive electricity is passed through it into the ground. Earthing can be done in various ways. Mostly in earthing a wire is attached to a plate or nail which is inserted into the ground from the main switch box. Now the electric circuit of our home consists of three wires; alive wire carries current and acts as apositive terminal,a neutral wire acts as anegative terminal and earthing wire carries any excessive electricity from the circuit into the ground.

Some of the electrical devices are:

1. Electrical Lamp

Electrical lamp converts electrical energy into light energy. There are two types of lamp. They are filament and fluorescent lamp.

2. Electric Bell

An electric bell is a source of sound that converts electrical energy into kinetic energy and then sound energy. An electric bell consists of a U-shaped soft iron core around which an insulated wire is wound to make it an electromagnet. It’s one end is fixed, while the other end is connected to a hammer which is free to move.

3. Heater

Heater transforms electrical energy into heat energy. The heater is used for cooking, boiling water, iron clothes and so on.

4. Radio/Television

Radio and television are strong means of entertainment and communication. Radio is an audio device whereas television is an audio-visual device.

5. Telephone/Mobile

Telephone or mobile is an important means of communication. Both are duplex means of communication. Mobiles are more portable and convenient than telephone

6. Computer

The computer is an electrical device which inputs, process, stores, and output devices. E-mail and internet are an important medium of communication for this generation.

Fuse

The fuse is the special wire that melts when the certain amount of electricity flows through it. It happens due to the heating effect (link to theheating effect) caused by electricity. Fuses are made according to the maximum amount of current flowing through the circuit. If a circuit needs small amperage of current then we can use fuse with low amperage (in household normally 5 to 15A of fuse is used) and if the circuit needs high amount of current then high amperage of fuse is used (in small scale industries up to 30A of fuse is used and in heavy industries fuse use varies greatly). Fuse is made from a special alloy of tin and lead and the amount of lead and tin determines the capacity of the fuse. The small wire is enclosed in a glass case and sealed with small iron plates. But if we are using a fuse box then, the setting is different.

Miniature Circuit Breaker (MCB)

MCB is improved and extended version of the fuse. It automatically switches off the electrical circuit during the abnormal condition of the network means in overload condition as well as the faulty condition. The fuse does not sense, but miniature circuit breaker does it in the more reliable way. MCB is much more sensitive to theover current than the fuse. In a fuse, melted wire needs to be replaced but in MCB wire does not need replacing.