Transmission of electricity

When electricity is supplied to various consumers, e.g. domestic and industrial premises, it is said to be distributed. All distribution in Nigeria are carried out with Alternating Current (AC) system. The following (AC) supply systems are available by the Power Holding Corporation of Nigeria.

(i) Single phase 2-wire

(ii) Single phase 3-wire

(iii) Three phase 3-wire

(iv) Three phase 4-wire

The three phase 4-wire is the most widely used for the basic reason that the other systems can be easily obtained from it.

Utilization of Electricity

We have discussed how electricity is from the generating station to sub stations, and distributed from there to homes, factories, etc. In order to enjoy the many advantages of electricity in premises, certain precaution, accessories and methods of wiring need to be adopted to avoid hazards or danger associated with the use of electricity.

Utilization in the Home and Industries and Types of Consumers

There are two main classes of electrical consumers, namely:

(i) Domestic consumers

(ii) Industrial consumers

The domestic consumers, e.g. private houses, like bungalows and multistory buildings, which are not for commercial purposes, utilize less electric power than commercial, industrial and institutional premises where the demand for electricity is much higher due to more electricity-consuming activities.

The total electric power in kilowatts (1000 watts) of appliances such as cookers, fans, refrigerators, grinders, blenders, water heaters, and lighting fittings, for both incandescent and discharge lamps in private homes, when added up, is quite small compared with the power consumed by industrial machines. These electricity-consuming appliances are generally referred to as electrical load. An electrical circuit is said to be loaded when one or more appliances are connected to the circuit to form a complete current flow path. A circuit is referred to an unloaded circuit when it is “offloaded”, i.e. when the load is removed by switching off.