knowledge hub: INSULATORS (ELECTRICAL)

Insulators are the materials which do not allow to flow current through them.We use insulators for the protection of Users aswel as the protection of the electrical dewices.
In insulation materials, valance electrons are tightly bonded to the their atoms .So we can consider curent is not flowing through this materials.
But in the real world perfect insulators do not exsist.Thats mean any kind of insulator must have a DILECTRIC STRENGTH value.If this dilectric value is very high , we can say that material is a gud insulator.

Materials Uses For The Insulators

Insulators that are made for high tension power transmitions are made from

Glass
Porcelain
Composite Polymers

Glass Insulators

Dilectric strength - 9.8-13.8 kV/mm.
Even glass has a higher Dilectric Strength , its Internal strains are less. So its difficult to do moulding and casting prosses.And they have a less mechanical strength.So manufactures stoped making glass insulators after 1960.

Porcelain Insulators

Dilectric strength - 4-10 kV/mm
Porcelain materials that uses to make insulators are rich of Alumina . So it gives a high michanical strength to the Isulator.

Polymer Composite Insulators

Composite Polymar insulators are less cost and lighter in the weight.
Dilectric strength of Polythylenen- 18.4-21.7kV/mm

Classification Of Insulations

Class 1 Insulations

In this concept , it is a must to ground the metal body and all ather exposed metal parts .these equipments can easily identified by the third pin on the power plug for the ground conection .

Class 2 Insulations

Also known as Double layered Insulations.This is highly used for potable type electrical equipments.(electric shavers, hair dryers and portable power tools). All ilectricaly energized compenents are totaly enclosed within an insulated body that privent any contact with live parts of the devise.

Types Of Insulations

Shackle Insulators