Apne highway ya road pe jaate hue electricity poles ke sath lage insulators to dekhe hi hogi, kya apne soch hai ki ye kya hai aur inko kyu lagaya jata hai?
Inn black disks ko insulators kehte hai, inka kaam high voltage transmission lines se flow ho rahe current ko poles se dur rakhna hota hai, taaki electricity poles ke andar se flow ho kar ground mein discharge na ho jaye. Inn insulator ko kV voltage ke according hi electric poles pe install kiya jata hai.Agar inn insulators ko poles mein na lagaya jaye toh, baarish ke time wires ke beech current flow ho sakta hai, jisse kaafi bada short circuit hoga.
Insulator ko high quality material compound jese porcelain se bnaya jata hai, jo line ko high mechanical strength, excellent electric insulating, aur anti-magnetic properties provide krta hai.
Porcelain material ka kaam high voltage ko resist krna hota hai. But, time to time iski resistance kam hoti jaati hai, jisse insulator me cracks bhi dekhne ko milte hai, aur usko replace krna padta hai.Esa extreme voltage ki waje se hota hai. Ye insulator commonly electric poles mein 11kV voltage level tak use kiye jate hai. Insulator ko 11kV voltagezada voltage ki transmission lines p ese hi bghit saare insulator ko series mein lagay jata haui jisse uski insulation badh jati hai. Insulator ko poles pr lagi electrical cables ke beech gap ko bhi maintain krta hai
Open air, mein use hone ke karan insulator ko baarish ke paani se bachane ke liye ek special design mein bnaya jata hai, jisse baarish ka paani divert ho jata hai aur insulator dry rehta hai. Simple shabon mein insulator ek protective device hai, jo voltage se hone wale damage se protection deta hai.
Ab suspension type insulator ke baare mein baat krte hai. Suspension insulator ko higher voltage, yani 33 kV se zada ke liye use kiya jata hai. Ek suspension insulator mein kayi porcelain discs hoti hai jo metal links se string ke form mein yani ek ke upar ek connected hoti hai. Har disc ko low voltage, jese 11 kV, ke liye design kiya jata hai. Suspension insulator mein number of disks, voltage ke level per depend krti hai.
Jab transmission line dead end pr hoti hai ya phir kisi sharp curve per, toh transmission liner pr bhot zada tensile load yani kheechaw padta hai. Isko support krne ke liye strain insulator ka use kiya jata hai. Strain insulator ko suspension insulator se hi banaya jata hai, inme farak ye hota hai ki suspension insulators ko vertically install krte hai, aur strain insulator ko horizontally install kra jata hai.
Ab shackle insulator ki baat krte hai, toh shackle insulator ko low yani 11kV voltage distribution lines mein strain insulator ke roop mein use krte hai. Shackle insulator bhi porcelain ya glass se banaye jate hai. Inn insulator ko vertically aur horizontally dono tareke se lagaya ja sakta hai. Lekin, underground cables distribution system ke baad inn insulator ka use kam ho gya hai.
History
Industrial archaeologists often come across porcelain insulator that are used to support overhead telephone and telegraph wires, especially on old buildings and industrial sites. Lekin ab tak, in insulators ki history aur evolution ke baare mein koi detailed account nahi mila hai. Jo bhi information hai, wo alag-alag jagah par scattered hai aur aasani se nahi milti. Aapko yeh jaan kar hairani hogi ki kuch insulator ab bhi istemal ho rahe hain jo ek sau saal purane hain. Yeh sirf railway installations mein nahi, balki kuch industrial buildings mein bhi dekhne ko milte hain.
Aam taur par, railway operating equipment jaldi hi use se chale jaate hain isse pehle ki wo industrial archaeologists ke liye interest ka subject ban sake. Lekin ek khaas exception hai: overhead transmission line ke liye insulator ka istemal. Lekin ab jaldi hi yeh bhi badal raha hai, kyunki bahut se overhead lines ko surface aur underground multi-channel cables se replace kiya ja raha hai. Bas bees saal pehle, har major road par telephone poles hote the, jinmein kabhi kabhi so se zyada wires hoti thi. Ab yeh poles almost khatam ho gaye hain aur zyada tar underground cables ka istemal ho raha hai. Jo overhead transmission lines ab bhi hain, wo aksar rural areas mein hain, lekin ab inmein bhi conventional insulator ki jagah plastic insulated wires ka istemal ho raha hai. Lekin, bahut se branch railways band hone ke bawajood, jo purani telegraph equipment thi, kuch overhead lines ab bhi desh ke bade hisson mein maujood hain. Yeh ek neglected field hai jo dhyan dene layak hai, warna ye sab evidence kho jaayega.
Overhead transmission lines ka istemal sirf telephony aur telegraphy ke liye nahi hota; railway operations ke liye bhi kaafi applications hain, jaise block circuit telegraphy, signal repeaters, track circuiting, signal lights, aur point position indicators, saath hi public address systems bhi istemal hote hain. Civilian uses mein telemetry bhi shamil hai, jisse reservoirs ya flood-prone rivers ki water depth ka remote indication milta hai.
Insulators ka pehla commercial use overhead telegraph transmission line ke liye 1838 mein GWR circuit ke saath hua tha, jo Paddington se West Drayton tak tha. Iska kaam 1842 mein shuru hua aur 1843 mein yeh Slough tak extend hua. 1854 tak, kai railway companies is technology ka use kar rahi thi. Dr. Dionysius Lardner ne UK ki 40 railway companies ke telegraphic communications ka zikr kiya tha; in companies ke installations ki kuch details Table 1 mein di gayi hain. Us waqt, major towns aur cities ko public telegraph services se link kiya ja chuka tha. Ek udaharan ke taur par, 20 shabdon ka ek message 5o miles ke liye 1s 0d (5p) mein, 100 miles ke liye 2s 6d (12½p) mein, aur zyada distances ke liye 5s 0d (25p) mein bheja ja sakta tha.
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