What is Electrical Breakdown ?

• The failure of electrical properties of insulating materials is known as "Electrical Breakdown."

OR

• Electrical breakdown or dielectric breakdown is when current flows through an electrical insulator when the voltage applied across it exceeds the breakdown voltage. This results in the insulator becoming electrically conductive.
• There are two types of electrical breakdown.

1. Global Breakdown
2. Local Breakdown

1. Global Breakdown :

• The complete failure of the electrical insulation between two electrode is known as "Global Breakdown".

2. Local Breakdown :

• The phenomenon of failure of insulating properties confined locally to  a part of the total insulation system provided between two electrodes is known as local breakdown.
• It is known as "Partial Breakdown" (PB).
• The classification of Partial Breakdown is given below.