Hariharan Srinivasan

The sub station will have all the protective and metering unit. It will have a Incoming lightning arrestor which will be a ebonite rod with small portion of sharp conducting end which will absorb the energy. The station will have an incoming fuse which will get connected between the incoming 132 kV line and incoming terminals. Special effort will be made that the terminals are insulated to withstand the 132 kV voltage. From incoming terminal special incoming cable goes to a oil cooled or Vacuum breaker Braker which will trip the line in case of any fault in the outgoing line. Breaker output will go to a 3 phase Transformer which will be a oil cooled Transformer with various protections.Oil Insulation has to withstand the Incoming voltage. Transformer steps down 132 kV voltage to 33kv voltage. Capacity of the Transformer will depend on the load requirement. There will be various protections for the Transformer such as over current,under/over voltage,pressure etc. The output of the Transformer will go through metering units tto monitor volltage,current,power,power factor etc. The output of the Transformer is normally taken through another set of Transmission lines to the destination where voltage will be further stepped down. Normally in the sub station only authorised persons can enter and will be kept locked. To handle any equipment in the sub station special hand gloves having required insulations are kept. Even if we have to replace fuse special rods whose bottom end is grounded is kept. For carrying out any work on the Transformer the breaker is tripped first and after that load end is completely discharged before touching any part.SUB STATION IS NORMALLY KEPT CLEAN DEVOID OF GRASS PAPERS ETC.so accidental fire does not take place

Computer is a Electronic device which perform arithmetic and logical operations. It contains Integrated circuit IC's like Microprocessor which perform logical and arithmatic operations and also contains Read only Memory(ROM) and Random access Memory(RAM) for storing information. For interfacing with computer there are normally other Integrated Circuits(IC's) known as Input output IC's. All these are normally mounted in a Printed Circuit board (PCB) To access the computer normally external Input devices like key board and mouse are provided. Computer output is normally given to external devices like CRT,Printer etc.