Ageing insulating material Experiment

SPARK-KING

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(Engineering Lectures and Engineering Solutions)

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09833066325 / 08796149007

2010

VIJAY BALU RASKAR

BE-Electrical / MBA - Operation

[Engineering Assignments]

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DESIGNED BY, PROF. VIJAY BALU RASKAR

SPARK-KING ….. Unique solution for Learning. VBR

Experiment No:

Title: Observe development of tracks due to

ageing on different Insulating Materials

Roll No:

Batch:

Date:

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EXPERIMENT NO:

OBSERVE DEVELOPMENT OF TRACKS DUE TO

AGEING ON DIFFERENT INSULATING MATERIALS TITLE: Study of insulating materials like mica, Bakelite, etc

AIM: To study different types and properties of insulating materials with

observation development of tracks due to ageing on different insulating materials.

THEORY: Requirements of good insulating materials:

Before selecting an insulating material for a particular application the

following properties need to be considered.

A] Mechanical Properties

B] Thermal Properties

C] Environmental including chemical Properties

D] Electric Properties

E] Economic Consideration

A] Mechanical Properties: The mechanical properties which are considered are

tensile strength, elongation, tensile modulus, compressive modulus, impact

strength, etc. Best of one property does not mean that material chosen will be the

best. Mechanability niches are important. Low viscosity liquids are used for X’mer

and switchgear. Porosity is another factor for consideration. High porosity

materials will absorb moisture.

B] Thermal Properties: thermal properties include temperature and time of

exposure. In this, what is important is at what temperature one can operate this

device for the required lifetime. Properties of materials change at lower

temperatures. In general, tensile strength, greater elongation, smaller elongation

makes material brittle. Fire is another aspect of thermal problem. The insulating

materials used must be stable within the allowed temperatures. The ability of

temperature to affect important properties like electrical, mechanical etc. has

made thermal properties all the more important. Some of the thermal properties

checked for certain insulating materials are melting point, flash point, volatility,

thermal conductivity, thermal expansion and heat resistance.

C] Environmental Properties including Chemical: Environmental properties

including chemical come in picture as to under what kind of operation must the

device operate in. Environment includes the effect of air, light, U.V rays, acid,

alkalis fumes and humidity.

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- Hydrolysis and oxidation should not occur in the insulating material. They

should be chemically stable and offer resistance to oils, solvents, acids and

alkalis.

- While in use of a material certain chemical changes take place, but its

properties should not change.

-Some insulating materials absorb moisture and this property is called

hygroscopicity.

- Ageing of a material occurs due to the effects of heat and chemical action and

voltage application.

E] Electrical Properties: The actual performance of an electrical circuit is a

function not only of the properties of materials but of geometry also. There is an

exact analogy with the mechanical properties. From the electric function point of

view the most important property is the dielectric strength of the insulation. It is

that value of voltage which causes the rupture of the insulating material in

practical use. Another important property is the dielectric constant which

determines the share of electric stress which is absorbed by the material.

Economic may or may not be an important factor for a given application. A good

insulating material should have a low dissipation factor, high insulation resistance

and good dielectric strength and high mechanical strength. They should have

high thermal strength. A good insulating material should have a low permittivity

and giving high discharge stress, free from gaseous insulation to avoid

discharges.

NOTE:- Stick color pictures of the following insulating materials and write

it’s Application and Properties.

1. Bakelite

2. Perspex

3. Mica

4. Micanite

5. Fiberglass

Also, add few points based on old insulating material problems and

disadvantages.

Stick insulating material picture from life (Home, Industry etc)

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RESULT:-

We understand the different insulating material and observed

development of tracks due to ageing on different insulating materials.

CONCLUSION:-

Thus, we studied different insulating materials properties and its application.

Education

Ageing insulating material Experiment