9 a] With the help of block diagram, discuss low voltage distribution system (400 V and 230 V) for domestic, commercial, and small-scale industry.
Solution :
The power is generated in generating station. The transmission system will deliver bulk power from generating station to distribution centers. Then distribution centers will distribute the power to various consumers. The block diagram for low voltage distribution system for domestic, commercial and small scale industries is as shown below.
The electric power from primary distribution line (11KV) is delivered to secondary substations. The secondary substations located near the consumer localities step down the voltage from 11KV to 415V using step down transformer. The 415V, 3phase- 4wire (R, Y, B, N) distribution is done for 3 phase loads like commercial buildings and small scale industries. Single phase voltage of 230V is supplied for domestic consumers through one phase and the neutral.