Nau'o'i da Dabbobi Da a Amfani a Tsakiyar Jirgin Karamin Rike (Tsakiya)
Suna Da Insulaturu A Yau Da Cikin Tsari
Akawo 5 suna da insulaturu a yau da cikin tsari a matsayin insulation overhead:
Pin Insulator
Suspension Insulator
Strain Insulator
Stay Insulator
Shackle Insulator
Pin, Suspension, da Strain insulators suna amfani a cikin systemen medium to high voltage. Amma Stay da Shackle Insulators suna amfani a cikin low voltage applications.
Pin Insulator
Pin insulators suna kai a kan insulaturu overhead a lokacin da suka gudana, amma suna amfani a cikin power networks zuwa 33 kV system. Pin type insulator zai iya zama one part, two parts ko three parts type, depending upon application voltage.
A 11 kV system muna amfani da one part type insulator inda butu daga pin insulator shi ne one piece of properly shaped porcelain or glass.
Saboda leakage path of insulator shine through its surface, it is desirable to increase the vertical length of the insulator surface area for lengthening leakage path. Muna bayar one, two or more rain sheds or petticoats on the insulator body to obtain long leakage path.
Karin haka rain shed or petticoats on an insulator serve another purpose. Muna design these rain sheds or petticoats in such a way that while raining the outer surface of the rain shed becomes wet but the inner surface remains dry and non-conductive. So there will be discontinuations of conducting path through the damp pin insulator surface.
A higher voltage systems – like 33KV and 66KV – manufacturing of one part porcelain pin insulator becomes more difficult. The higher the voltage, the thicker the insulator must be to provide sufficient insulation. A very thick single piece porcelain insulator is not practical to manufacture.
A wannan case, muna amfani da multiple part pin insulator, inda some properly designed porcelain shells are fixed together by Portland cement to form one complete insulator unit. Muna amfani da two parts pin insulators for 33KV, and three parts pin insulator for 66KV systems.
Designing Consideration of Electrical Insulator
The live conductor attached to the top of the pin insulator which is at the live potential. Muna fix the bottom of the insulator to supporting structure of earth potential. The insulator has to withstand the potential stresses between conductor and earth. The shortest distance between conductor and earth, surrounding the insulator body, along which electrical discharge may take place through the air, is known as flashover distance.
When the insulator is wet, its outer surface becomes almost conducting. Hence the flashover distance of insulator is decreased. The design of an electrical insulator should be such that the decrease of flashover distance is minimum when the insulator is wet. That is why the uppermost petticoat of a pin insulator has umbrella type designed so that it can protect, the rest lower part of the insulator from the rain. The upper surface of the topmost petticoat is inclined as less as possible to maintain maximum flashover voltage during raining.
The rain sheds are made in such a way that they should not disturb the voltage distribution. They are so designed that their subsurface at a right angle to the electromagnetic lines of force.
Post Insulator
Post insulators are similar to Pin insulators, but post insulators are more suitable for higher voltage applications.
Post insulators have a higher number of petticoats and a greated height compared to pin insulators. Muna mount this type of insulator on supporting structure horizontally as well as vertically. The insulator is made of one piece of porcelain and it has clamp arrangement are in both top and bottom end for fixing.
The main differences between pin insulator and post insulator are:
