When electricity I'd supplied to various consumers, e.g. domestic and industrial premised, it is said to be distributed. All distributions in Nigeria are carried out with Alternating Current System.
The following (AC) supply systems are made available by the power holding Company of Nigeria (Phcn) :
1. Single phase 2 - wire
2. Single phase 3 - wire
3. Three phase 3 - wire
4. Three phase 4 - wire
The three phase 4 wore system is the most widely used , for the basic reason that the other systems can be easily obtained from it. The basic principle if the generation of alternating current has been explained in my previous write up.
The power station generates electricity at a lower voltage. The power transmission (PT) transformer steps up the voltage to approximately 1,000V for every 1.6km of transmission.
After lowering the voltage at the consumer's end of transmission system with a step down transformer, the electric power must still be routed to various placed of utilization, e.g. houses , factories, schools, etc. The distribution system is usually designed to cover a specific area. The method of distribution is mostly overhead lines on ceramic pin type insulators mounted on cross arms wooden or concrete poles. The height of the pole varies from 10m to 15m.
