05/02/2023 1

Jodhpur Vidyut Vitran Nigam Ltd.

Presented by:Dharmendra Kumar

(13EJIEE404)(IV B.Tech., VII Sem.)

7EETR: PT & IV

Power Insulator

05/02/2023 7EETR: PT & IV 2

Jd.V.V.N.L Logo

Table of Contents

05/02/2023 37EETR: PT & IV

Introduction Types of Insulator Properties of Insulator Testing of Insulator Cause of Insulator failure Application of Insulator

Introduction Transmission line insulators are device

use to contain separate or support electrical conductor on high voltage electricity supply network.

The insulator provide necessary insulation between the line conductor or support thus prevent any leakage current from conductor to earth.

Good insulator :- wood , Glass , Plastic.05/02/2023 7EETR: PT & IV 4

Types of Insulator1. Pin type insulator2. Suspension type insulator3. Strain type insulator4. Stay insulator5. Shackle insulator

05/02/2023 7EETR: PT & IV 5

Pin type insulator Pin type insulators are used for

transmission and distribution of electric power at voltage up to 33kv.

It is made of nonconducting materials glass and porcelain.

Beyond operating voltage of 33kv.

05/02/2023 7EETR: PT & IV 6

Pin type insulator

05/02/2023 7EETR: PT & IV 7

Suspension type Insulator These insulators consists of a number

of porcelain discs connected in series by metal links in the form of a string.

One disc is designed for a low voltage , 11kv.

66kv voltage line used six disc. It provide greater flexibility to the

line.

05/02/2023 7EETR: PT & IV 8

Suspension type insulator

05/02/2023 7EETR: PT & IV 9

Strain type Insulator When there is a dead end of the line

or corner or sharp curve. It is two or more strings are used in

parallel. It is mechanically strong. It is used for low voltage line (<11kv)

05/02/2023 7EETR: PT & IV 10

Strain Insulator

05/02/2023 7EETR: PT & IV 11

Stay insulator The stay insulators are to be insulated

from ground at a height(>3m). It is used for low voltage line nearly

about 33kv. It is usually made of porcelain and is so

designed that in case of breaks them the stay wire will not fall on the ground.

05/02/2023 7EETR: PT & IV 12

05/02/2023 7EETR: PT & IV 13

Shackle Insulator They can be directly fixed to the pole

with a bolt or to the cross arm. It can be used both in horizontal and

vertical position. The conductor in the groove is fixed

with a soft binding wire. Mostly used distribution purpose.

05/02/2023 7EETR: PT & IV 14

Shackle insulator

05/02/2023 7EETR: PT & IV 15

Properties of Insulator 1. Mechanically strong.2. High insulation resistance.3. High dielectric strength.4. High relative permittivity.5. Free from internal impurities.6. It should not get affected change in

temperature.

05/02/2023 7EETR: PT & IV 16

Testing of insulator1. Mechanical strength test.2. Electrical insulation test.3. Environment test.4. Corona test.5. Temperature test.6. Puncture voltage test.7. Porosity test.

05/02/2023 7EETR: PT & IV 17

Cause of Insulator failure1. Flashover:-The most common cause of

the insulator failure is the flashover, that causes unequal expansion of the porcelain thereby shattering the insulator with big cracks.

2. Cracking of insulator:-This cause occurs due to unequal expansion of steel , porcelain and cement during the varying conditions of cold and heat.

05/02/2023 7EETR: PT & IV 18

Cause of Insulator failure3.Porosity of material:-This cause occur usually absorb moisture from the atmosphere or the cement, thereby decreasing the insulation resistivity of the material.4.Short-Circuits:- Two or more conductor are earth through the large birds.5.Mechanical stresses.

05/02/2023 7EETR: PT & IV 19

Application of insulator1. It is used in transmission and distribution

of electricity supply.2. It is provide necessary safety for human

and animals.3. Many electronic components used

insulation materials like plastic.4. Electricity supply board used insulation

05/02/2023 7EETR: PT & IV 20

Conclusion Thus a brief idea about the types of

insulator used in overhead transmission line has been obtained. Each type of insulator is having it’s own area of application. The system was having a flaw that proper track record of the insulator and poles damaged or replacement was not taken care of.

05/02/2023 7EETR: PT & IV 21

References www.wikipedia.com www.electrical4u.com

05/02/2023 7EETR: PT & IV 22

Thank you.......

05/02/2023 7EETR: PT & IV 23

Conclusion

05/02/2023 247EETR: PT & IV

05/02/2023 25

Thank You……

7EETR: PT & IV

05/02/2023 7EETR: PT & IV 26

References

05/02/2023 277EETR: PT & IV