# What is the basic insulation level?

## What is the basic insulation level?

Insulation levels are designed to withstand surge voltages, rather than only normal operating voltages….Basic insulation level, kV. (standard 1.5- × 40-μs wave)

Basic insulation level, kV (standard 1.5- × 40-μs wave)
1.2 30 45
2.5 45 60
5.0 60 75
8.7 75 95

## What is the purpose of basic insulation level?

Definition: A design voltage level for electrical apparatus that refers to a short duration (1.2 x 50 microsecond) crest voltage and is used to measure the ability of an insulation system to withstand high surge voltage.

## What is basic impulse level for Transformers?

Basic impulse level is a means to express the ability of the insulation system to withstand high voltage surges.

## What is the BIL rating?

BIL rating specifies the minimum voltage that transformer can withstand under this condition. The method of testing of the transformer for BIL has been defined and set by IEEE and ANSI standards. The wave shape has been also defined which is commonly known as 1.2/50 μs voltage wave.

## What is basic impulse insulation?

When lightning impulse over voltage appears in the system, it is discharged through surge protecting devices before the equipments of the system gets damaged. This minimum voltage rating is defined as BIL or basic insulation level of electrical equipment. …

## What is impulse level?

Definition: A reference impulse (voltage) insulation strength expressed in terms of the peak value of the withstand voltage of a standard impulse voltage wave. It is used to express the ability of electrical equipment such as transformers to withstand certain levels.

## What is bil or basic insulation level?

The basic insulation level or BIL of an electrical equipment determines the principle dielectric qualities of the apparatus and is expressed for impulse tested apparatus by peak value of the 1/50 microsecond full wave withstand voltage.

## What is rated voltage?

The rated voltage is the value of voltage used to designate the switchgear and to which is related its operating performance. The rated voltage indicates the upper limit of the highest voltage of systems for which the switchgear is intended.

## What is the basic insulation level ( BIL )?

Definition of Basic Insulation Level (BIL) Introduction to BIL Insulation levels are designed to withstand surge voltages, rather than only normal operating voltages. Since the insulation lines and equipment is protected by surge arresters draining the surges rapidly before the insulation is damaged, the arrester must operate below the minimum

## Which is an example of a minimum insulation level?

Since the insulation lines and equipment is protected by surge arresters draining the surges rapidly before the insulation is damaged, the arrester must operate below the minimum insulation level that must withstand the surges. An example is shown in Figure 1a below.

## How is the insulation level of a switch determined?

The user must define these for the equipment manufacturer. The rated insulation level is the value of the impulse withstand voltage and the value of the power frequency withstand voltage, which together characterise the insulation of the switchgear with regard to its ability to withstand the electric stresses.

## Why is it important to know the insulation level?

Insulation levels are designed to withstand surge voltages, rather than only normal operating voltages. Since the insulation lines and equipment is protected by surge arresters draining the surges rapidly before the insulation is damaged, the arrester must operate below the minimum insulation level that must withstand the surges.