Electrical insulators are known as power insulators. They are essential components in both overhead lines as well as transmission line systems. Electrical insulators are mounted on the poles, and power towers for preventing electric current from flowing to some unwanted areas. Materials of electrical insulators are usually of different kinds like conductors or semiconductors. It depends on electrical needs and dimensions, the product range of the OHL insulator’s design varies.
Why is Overhead line insulators necessary?
According to the statistics of power line accidents, so many people get killed by coming in contact with live power lines. The miserable statistics even consist of normal passersby along with workers working on power line installation or repairing. In a high voltage power transmission project, OHL insulators must be the top priority for the sake of preventing accidents.
What are Overhead Power line Insulators?
Electrical insulators are a kind of material whose electric charges do not freely flow. Resistance of the flow charge makes it almost impossible for conducting an electrical current even while an electric field passes. The main property that makes electrical insulators vital is – their resistivity. Overhead line insulators have great resistivity as compared to conductors and semiconductors. OHL insulators can support suspended wires’ load without permitting the flow of electric current through a tower to the etiler escort ground.
What are different materials for insulators?
When purchasing electrical insulators for power lines, it is important to understand what they are made up of. Every insulator is useful in preventing the flow of electric current but the level of insulation may vary. Some of the common materials used for constructing electrical power line insulators are porcelain, glass, composite polymers etc.
a) Glass insulator
Glass is one of the oldest materials to be used for constructing insulators, especially for overhead lines. Glass has quite higher dielectric strength due to the annealing procedure used for manufacturing them. It has high resistivity to electricity and at the same time has a low coefficient to thermal expansion. Both the features of glass can be advantageous for becoming a good insulator. The high tensile strength of the glass material prevents it from heating up. the glass material can also serve for many years without even degrading its mechanical or electrical properties. Glass insulators are cheaper too as compared to porcelain ones.
b) Porcelain insulator
Porcelain is also a preferred material for overhead transmission lines. Porcelain offers protection against dust, moisture and some other impurities. It doesn’t have porosity. Porcelain helps in preserving its dielectric strength. Insulators made up of porcelain usually do not consist of any holes or cracks and it keeps their insulation resistance very high. Another vital reason for porcelain’s popularity as an OHL insulator is – Its flexibility. Easy casting makes porcelain easy to use and makes any design or shape, unlike glass.
c) Polymeric insulator
The polymeric insulator is known as a composite insulator. The main benefit of using an insulator made of this material is- that it’s lightweight. These materials can be easily transported without getting damaged or broken down. The lightweight feature means they will be exerting very less load on an electric cable. The polymeric insulators have high tensile strength. These insulators are ideal for places where there is a high level of pollution.
So it is upon the user to decide which material to select for the insulator.
What are some vital parameters which insulating material must meet?
> High electrical resistance for preventing leakage of current
> High mechanical strength for supporting the load.
> The material for OHL insulators has to be non-porous.
> Material of construction must be impurities free.
What are the factors to consider while selecting the correct OHL insulator?
You must have seen there are different kinds of OHL insulators. Every insulator has its features and properties. Some of the major factors to consider while purchasing the best insulator are:
a) Voltage head
b) Material of the respective insulator
c) Poles’ distance
d) Dielectric properties of insulators
e) Cost of insulator
f) Environmental condition.
Insulators are essential to be installed in the Overhead line. OHL insulators protect transmission lines from overvoltages that may happen because of switching, lighting and other causes. With overhead line insulators to a great extent, you can prevent accidents.
