OVERHEAD LINE INULATOR
Nov 18, 2014
OVERHEAD LINE INULATOR
Overhead line insulator
1. Insulators2.Insulator materials3.Properties of insulator 4.Types of insulator5.String efficiency
Insulator
Insulators are used between line conductors and supports.The main function of insulators is to provide perfect insulation between the line conductors and supports. And prevent any leakage current from the line conductors to earth through supports……..
Properties of insulatorHigh mechanical strengthHigh insulation resistanceHigh dielectric strengthFree from impuritiesHigh permittivity
Insulator materialsa..porcelain b..glass
Types of insulator
1-pin type insulator2-suspension type insulator3-string insulator4-shackle insulator5-stay insulator
1..Type of insulator
*pin type insulator
It is used for various voltage label.It becomes bulky for higher voltage lable.
*suspension type insulatorCemented cap type Hewlett or interlinking
type
Main drawback is fine crack and early failure.
*strain insulator
It is used at the dead end of line .It is used for higher voltage.
*shackle insulator
It is also called spool insulator.Used for low voltage distribution line.
*stay insulator
It is called egg insulator.Create insulation b\w pole and stay clamp.
String efficiencyThe nonuniformity in the voltage
distribution over a string of suspension insulators is expressed in term of a parameter called “string efficiency”.
Where ‘n’ is no of units or disks in string
String efficiency=voltage across the string /n*(voltage across the unit adjacent to the line conductor)
THANK YOU…..
PRESENTED BY--- ROHIT SINGH (LKO) PAWAN KUSHWAHA (BALLAN)