BIL or Basic Insulation Level Definition Table and Calculation

Basic Insulation Level Definition When lightning impulse over voltage appears in the system, it is discharged through surge protecting devices before the equipments of the system gets damaged. Hence, the insulation of such equipment must be designed to withstand a certain minimum voltage before the lightning impulse over voltage gets discharged through surge protecting devices. … Read more

Dielectric Properties of Insulation

We can first go through the description of dielectric materials. It actually does not conduct electricity. They are insulators having very low electrical conductivity. So we have to know the difference between dielectric material and insulating material. The difference is that insulators block the flow of current but the dielectrics accumulate electrical energy. In capacitors, … Read more

Electrical Insulator | Insulating Material | Porcelain Glass Polymer Insulator

Electrical Insulator must be used in electrical system to prevent unwanted flow of current to the earth from its supporting points. The insulator plays a vital role in electrical system. Electrical Insulator is a very high resistive path through which practically no current can flow. In transmission and distribution system, the overhead conductors are generally … Read more

Types of Insulators Used in Transmission (Overhead) Lines

There are 5 types of insulators used in transmission lines as overhead insulation: Pin Insulator Suspension Insulator Strain Insulator Stay Insulator Shackle Insulator Pin, Suspension, and Strain insulators are used in medium to high voltage systems. While Stay and Shackle Insulators are mainly used in low voltage applications. Pin Insulator Pin insulators are the earliest … Read more

Insulation Coordination in Power System

Insulation Coordination in Power System was introduced to arrange the electrical insulation levels of different components in the electrical power system including transmission network, in such a manner, that the failure of insulator, if occurs, confindes to the place where it would result in the least danmage of the system, easy to repair and replace, … Read more

Electrical Insulator Testing | Cause of Insulator failure

To ensure the desired performance of an electrical insulator, that is for avoiding unwanted insulator failure, each insulator has to undergo numbers of insulator test. Before going through testing of insulator we will try to understand different causes of insulator failure. Because insulator testing ensures the quality of electrical insulator and chances for failure of … Read more

Measurement of Insulation Resistance

We define insulation resistance as the ratio of applied direct voltage across an insulation to the corresponding current through it. Mesaurement of inslation resistance is quite important. We normally take the reading of the measurement at a certain time after application of test voltage. The standard duration of voltage application are 1 minute or 10 … Read more