Rahmany - Khorassan Regional Electric Company

Providing a good earthing system is one of the most indispensable means in the distribution network. Expansion and maintanance of the system should be considered carefully in cities and rural regions. Ground resistance is the main focus for the engineers, and must be reduced to minimum reasonable amount of 5 ohms or less. It is a proper means in preventing damages to the installations. During the normal or faulty conditions the current will pass through the ground wire to the earth, and in this way no voltage will apear in the neutral point. To do the earthing in existing distribution networks, or the ones under construction generally wells are dug and copper or galvannized sheets are inlayed or copper weld rods are poundes, null is connected to the earth via copper wires or cables or galvanized band. The deficiency of the parts as cartridge or fastener causes these joints to be done skipily,so that many of them get disrupted in a short while creating an obvious danger for the networks and the ones who passes by. so this connection must be done the way while being economical, never gets disrupted and does not diminish the safety. This paper discusses about a method of distribution networks earthing and connection of null wireto the ground, execution, fe asibility, economy of this method and existing methods have been compared, and advantages and disadvantages of each method are breifly described.