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Chapter :, , ORTHOGRAPHIC PROJECTIONS, _ OF SIMPLE ELECTRICAL PARTS, , 4.1 BUS BAR POST, , Porcelain and glass insulators are best suited for outdoor insulation because of their unique, properties. Bus bar post supports the copper or aluminium bus bar with the help of nuts and bolts., The bus bar is connected at the top portion of the busbar post with the help of nuts and bolts., , Bus bar support insulator has good characteristics of water aging, tracking and corrosive, resistance. The bus bar posts are designed for high electrical performance, pollution resistant and, should be able to prevent flash over due to pollution. They should be able to work on the severely, polluted sites without special clearing. Busbar posts are usually made of porcelain but now-a-days, silicon rubber is also being used., , A post insulator unit is a constituent part of a post insulator and consists of a permanent, assembly of one or more insulating parts complete with other metallic part to facilitate attachment, , , , to it., , , , Fig. 4.1 : Bus Bar Post, , Example 4.1. Draw the following views of bus bar post shown in Fig. 4.2 to a suitable, Scale ;, , 85
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oN, , *6 ISHAN'S Electrical Engineering Design and Drevin, , (a) _ Front view in section looking in the direction of arrow ‘A’., (b) Side view in section looking in the direction of arrow ‘B’., (c)_ Top view., , © 10 Hole 20 deep, © 40 Hole 52 deep, , , , , jase holes, , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , @ 10- 150 Apart, B, Fig. 4.2 : Isometric view of Bus Bar Post, Solution., 17. 70 , o10, po G10 . Bs pt E, . at DA, T oP fia, dk 10 af rer 76, 60}-—>}, t 1, al G! | Lab tep eat], =reh os __85_3 t Fhok *, a6) 115 118 70, 145, (a) Front view (b) Side view, 90, 15 [| G10 I] 2 Holes, 610, aaa] ||, jam fit-=— 10. 1-900, 45, , , , , , , , (c) Top view, Fig. 4.3 : Orthographic views of bus bar post, , y.
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y, , ic projections of Simple Electrical Parts, , mple 4.2. Draw the following views to a suitable scale: °°’, , a, i front view right half in section, (6) Side view., Top view., , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , @ 2 al 8p, OabHole Sdacn, g, yf senna’, \, Fig. 4.4 : Bus Bar Post in isometric view, Solution. 46, bee He, i 2 Eee, r ! !, ' 1 1 1, i go § | |: il, y § 1 1 1, Tig Tt Tt, i ta ; | -C--c 14, eS Sa, 8, 56-———*"!, 4+ se, a, Mon br 2, g iq VA, | on #,, ACT TO, r] 74, , , , , , Fig. 4.5: Orthographic views of bus bar post, , 87
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NO, , 88, ISHAN'S Electrical Engineering Design ang Drayg, Ng, , 4.2 INSULATOR, , In electrical power transmission from generating stations to the consumers apart from, overhead transmission lines (ACSR conductors), line supports etc. insulators play an impo,, role. There are various types of insulators available which are widely used in transmission, distribution according to the voltage rating. Insulators are required to isolate the conductor,, transmission and distribution lines from the line supports like steel lattice towers, tubul,, poles and various other types of poles depending upon line voltage. Insulators are used frm,, voltage rating ranging from 220 volts to 220 kilovolts. The material mainly used for Making, , insulators is porcelain. Apart from porcelain, steatite and toughened glass are also useq fe, making insulators. Porcelain in its natural form is rough in appearance. It is glazed to make it, , smooth and free from porosity. A good insulator should have following properties., (i) It should be moisture resistant., , (ii) It should not absorb polluted and toxic gases., (iii) Its mechanical strength should be high and weight should be low., , (iv) Insulation resistance should be high so that there is no leakage current., (v) It should be able to withstand large temperature differences during summer and writer, seasons., , Insulators are mainly classified into:, , Pin type insulators, Shackle type insulator, Stay or Guy wire insulator, Suspension type insulator, Strain insulator, , Disc type insulator, , DAwpwne, , 4.2.1 Pin type Insulators, , Pin type insulators are mainly used on overhead transmission and distribution lines 10, support and insulate the conductors in normal areas, polluted areas and high altitude regions., , Pin insulators are used on medium voltage overhead distribution lines (11kV, 22kV oF, 33kV) to carry the conductors to tower bodies to distribute power from substation to tow? and, inside the town networks. Pin type insulators are manufactured with creepage distance from 320, , mm upto 1400 mm and 10 KN bending strength.
