Correct Answer - Option 3 : Insulator glazing
Causes of Insulator Failure: There are different causes due to which failure of insulation in the electrical power systems may occur:
Cracking of Insulator:
- The porcelain insulator mainly consists of three different materials.
- The main porcelain body, steel fitting arrangement, and cement to fix the steel part with porcelain.
- Due to changing climate conditions, these different materials in the insulator expand and contract at different rates.
- These unequal expansion and contraction of porcelain, steel, and cement are the chief cause of the cracking of insulators.
Porosity in The Insulation Materials: If the porcelain insulator is manufactured at low temperatures, it will make it porous, and due to this reason it will absorb moisture from air thus its insulation will decrease and leakage current will start to flow through the insulator which will lead to insulator failure.
Flash Over Across Insulator: If a flashover occurs, the insulator may be overheated which may ultimately result in shuttering of it.
Mechanical Stresses on Insulator:
- If an insulator has any weak portion due to a manufacturing defect, it may break from that weak portion when mechanical stress is applied to it by its conductor.
- These are the main causes of insulator failure. Now we will discuss the different insulator test procedures to ensure the minimum chance of failure of insulation.
Note: Glazing on ceramic insulators is done to make it smooth and non-absorbent.
