What are the important requirements of a insulating material, Electrical Engineering

Assignment Help:

What are the important requirements of a good insulating material?

Important requirements of good insulating materials:-

The necessity of good insulating materials can be classified as mechanical, electrical, chemical and thermal. Electrically the insulating materials must have high resistivity to decrease the leakage current and high dielectric strength to enable this to with stand higher voltage without being broken down or punctured. Also the insulator must have small dielectric loss. Insulators must have low density; a uniform viscosity for liquid insulators makes sure uniform thermal and electrical properties. Gaseous and Liquid insulators are used also as coolants. For illustration, transformer oil, hydrogen and helium are used for both insulation and cooling purposes. For such materials, good thermal conductivity is desirable. The insulators must also have small thermal expansion to prevent mechanical damage. This must be non ignitable or if ignitable, this must be self-extinguishable.

Chemically, the insulators must be resistance to liquids, oils, gas fumes, alkalies and acids. This must not deteriorate by the action of chemicals in soils or with contact with other metals. The insulators must not absorb water particles, because water lowers the insulation resistance and the dielectric strength. Insulating materials must have definite mechanical properties depending upon the use to that they are put. Therefore when used for electric machine insulation the insulator must have sufficient mechanical strength to withstand vibration. Fine heat conducting property is also desirable in this case. Illustration of insulating materials is mica and porcelain. Mica sheets are employed for the insulating leaves in between commutator segments. For transmission line insulators, rail support on railways and conductor, porcelain insulators are used.


Related Discussions:- What are the important requirements of a insulating material

Discuss the closed-loop behavior, Q. Discuss the closed-loop behavior? ...

Q. Discuss the closed-loop behavior? Consider an elementary feedback control system, as shown in Figure, with H = 1. The output variable c and the input e to the direct transmi

Installation of meters and verification of connections, Installation of Met...

Installation of Meters and Verification of Connections Apart from testing and calibrating the meters they must be properly installed as per the links diagram. The points in wh

Determine the rectified load voltage, Consider the circuit of Figure (a) wi...

Consider the circuit of Figure (a) with v S (t) = 10 cos ωt. Use the piecewise-linear model of the diode with a threshold voltage of 0.6 V and a forward resistance of 0.5  to dete

Transformers, What is the difference between “Insulating,” “Isolating,” and...

What is the difference between “Insulating,” “Isolating,” and “Shielded Winding” transformers? Can Acme Transformers be reverse connected? . Can Transformers develop Three Phase po

Machine language - first generation language, Machine Language ( First Gene...

Machine Language ( First Generation Language) As we have  already discussed that all digital  circuits  can identify  only two  states which  can be specified  by 0 and i henc

Mutual inductance and coefficient of coupling, Mutual inductance and coeffi...

Mutual inductance and coefficient of coupling: The equivalent inductance of two series connected coil (with mutual inductance among them) is 0.8 or 0.2 Henry based on the rela

Transformers, Are you able to give a list of factors that could be consider...

Are you able to give a list of factors that could be considered as the transformer''s characteristics?

Find out form factor and peak factor, Find out Form factor and Peak factor:...

Find out Form factor and Peak factor: For the output of full wave rectifier, find out (a) RMS value, (b) Average value, (c) Form factor, and (d) Peak factor. S

Digital electronic, What are the advantages of wired-AND connection of digi...

What are the advantages of wired-AND connection of digital IC

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd