This equipment is used to convert voltages from one value to another, either upwards or downward, I e. Step up or step down respectively. The energy at high voltages transmitted by the national grid system (pool or bank of all electrical energy from various power stations in the country) , is fee into grid sub stations for the transformation of the transmission voltages of 66kv and 33 KV. This secondary transmission is for large consumers such as factories and those in areas of high load densities. Step down transformers are required to reduce the high voltages from 33kv to 11kv , and from 11kv to 415v to be distributed to premises. Transformers vary in sizes , and are rated in terms of KVA ( kilo volt ampere). A s farm settlement or estate sometimes will need just a transformer of 100 KVA usually mounted on the HV 'H' pole. Large sizes of transformers can be seen bow the high voltage lunes installed on concrete bedding with protective guards of barbed wire fences to prevent intruders from gaining easy access in to the premises.
