Electrical Insulator Materials
Did it ever occur that items like glass, air, and wood could play a vital role in Electrical purposes? It may come to you as a big surprise, but glass, plastic, paper, cardboard, wood, and even dry air are common Electrical Insulator materials. Let us begin with the Electrical Insulator definition before discussing the properties of Insulators and the uses of Insulators.
What is an Electrical Insulator?
Technically, you need to understand the Electrical Conductor’s concept to master the topic of the Electrical Insulator, and the application of Insulator. The Electrical Conductor’s materials enable the flow of the Electrical current or charges in a single or multiple directions. In other words, the Conductors of Electrical materials can be metals, like copper and non-metallic materials, such as graphite as they have free electrons. For example, if you want to charge your mobile, you plug it in the socket. The electrons present in the Electrical Conductor allow your phone to be fully charged.
On the contrary, Electrical Insulator materials do not allow free flow of Electric currents or charges. The Electrical Insulator materials give very little freedom for the electrons to drift from atom to atom. Thus, Electrical Insulators are a poor Conductor of Electricity. You can get a better understanding with the help of an Electrical Conductor example. You must have observed that the outer covering of your phone charger plug is made from plastic so that the Electric charges do not pass on to human skin. The following is a list of Electrical Insulator examples.
Styrofoam
Plastic
Wax
Rubber
Dry air
Glass
Ceramics
Rubber
Teflon
Mica
Quartz
Porcelain
Asphalt
Uses of Insulators
You must be wondering why are Electrical Insulators important for us when Electric charges cannot be passed through it? Generally, Electrical Insulators are highly useful at home, offices, streets, etc. They are used in Electrical appliances and equipment. Unfortunately, human skin is one of the best Conductors of Electric charges. Furthermore, the presence of Electrical Insulator materials prevents and protects Electrical devices from generating high voltage. There are innumerable uses of Insulators. They are listed below.
It prevents the passing of high-voltage in an Electric circuit.
It helps in reducing the cost of energy.
It helps in saving the environment by controlling the emission of pollutants.
It improves process performances.
It protects from Electric shock or electrocution.
It allows the soundproofing of appliances.
Application of Insulator
Since the Electrical Insulator materials bind the electrons tightly, it prevents the electrons from floating from atom to atom. Thus, they prevent the conduction of Electric charges. Given the benefits of there are multifold applications of the Electrical Insulator. They are applied to-
Circuit boards
Coating of Electric wires
High voltage appliances
Coating of cables
Coating for Electric poles on the streets
Types of Electrical Insulation in Overhead Lines
Electrical Insulators can withstand the charges from Electricity. They are broadly classified into three types of Electrical insulation based on their operating voltage levels and applications.
Pin Type Electrical Insulator
A pin Insulator is best for supporting low voltage line Conductors. A single piece of pin Insulator is used in 11kV, and the double piece is applied to 25kV. Above 44kV, three or four pieces of pin Insulators can be used. An Electrical Insulator has a porcelain shell. So even if the outer surface of an Electrical appliance gets wet, the inner surface is dry to keep it leakage resistant.
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Suspension Type Electrical Insulator
Suspension Electrical Insulators are best to handle high-voltage transmission lines. This type of Electrical Insulator has porcelain discs inside arranged in a series through metal links such that they have a string-like appearance. The arrangement of Insulators highly depends upon the weather condition, voltage, the size of the Insulator, etc.
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Strain Type Electrical Insulator
Another name for strain Insulator is tension Insulator. They are best for high voltages when the Electrical line is subject to change in the direction of the line, and at higher-tension areas at sharp curves, river crossings, etc. It is useful in minimizing the excessive tension in the line. Strain Electrical Insulators have diElectric properties. Additional strings can be added when the tension begins to aggravate.
Fun Facts
You would be surprised to know that the diamond necklace you wear on a special occasion is an excellent Electrical Insulator material.
A high-voltage area, which is dangerous, is enclosed in fiberglass or glass to prevent the conductivity of charges to pass.
Your Electrician uses a special screwdriver with a plastic coating to check the passage of Electrical charges without getting electrocuted.
Difference between Conductor and Insulator
Quick Summary
Here’s a quick summary of the topic of Electrical Insulators and their examples.
This was all about Electrical Insulators, properties and their types. For more such information, access free resources available on the Vedantu website useful for the state board, CBSE, ICSE, and competitive examinations. All NCERT Solutions for all subjects are available on the Vedantu website.
FAQs on Electrical Insulator
1. What is an electrical insulator, with an example?
An electrical insulator is a material whose internal electric charges do not flow freely. Because of this, it does not conduct an electric current under the influence of an electric field. The electrons in an insulator are tightly bound to their atoms, preventing them from moving. A common example is the plastic or rubber coating on electrical wires, which prevents electric shock and short circuits.
2. What are some common examples of electrical insulating materials?
Many materials used in daily life and industry serve as excellent electrical insulators. Some common examples include:
- Rubber
- Glass
- Plastic
- Porcelain and other ceramics
- Dry wood and paper
- Mica
- Teflon
- Pure water
3. How do electrical insulators work at an atomic level?
At the atomic level, electrical insulators work because their electrons are very tightly bound to their respective atoms. Unlike conductors that have many free electrons, insulators have a large energy gap, known as the band gap, between their valence band and conduction band. An extremely high amount of energy is required to force an electron to jump this gap and move freely, which is why these materials effectively resist the flow of electric current.
4. What is the difference between an insulator and a dielectric?
While all dielectrics are insulators, the terms highlight different properties. An insulator is defined by its primary function of blocking the flow of electric current. A dielectric is an insulator that, when placed in an external electric field, can be polarised. This means its internal positive and negative charges shift slightly, creating an internal electric field that opposes the external one. This ability to store energy is crucial in devices like capacitors.
5. What are the key properties that make a material a good electrical insulator?
A good electrical insulator is characterised by several important properties. It must have very high resistivity to prevent current leakage. It also needs high dielectric strength, which is its capacity to withstand a strong electric field without breaking down. Additionally, for practical use, it should be mechanically strong, non-porous to resist moisture, and stable across a range of temperatures.
6. What are the main types of insulators used in high-voltage transmission lines?
In high-voltage power systems, specific types of insulators are used to ensure safety and manage high mechanical loads. The three main types are:
- Pin Insulators: Used for supporting conductors in distribution lines, typically for voltages up to 33kV.
- Suspension Insulators: Comprise a string of discs used for high-voltage transmission lines (above 33kV). The number of discs increases with the voltage.
- Strain Insulators: Designed to handle high mechanical tension, used where a transmission line changes direction, at dead-ends, or across long spans like river crossings.
7. Can an electrical insulator ever conduct electricity?
Yes, an insulator can be forced to conduct electricity if the voltage applied across it is extremely high. This phenomenon is called dielectric breakdown. When the voltage exceeds the material's dielectric strength, the strong electric field can tear electrons away from their atoms, causing a sudden rush of current. This often permanently damages the insulator. A natural example of this is lightning, where air, normally an insulator, breaks down under immense voltage.
8. Why is pure water considered an insulator while tap water is a conductor?
This is a key distinction based on purity. Pure, deionised water (H₂O) has very few free charge carriers and is a poor conductor of electricity, thus acting as an insulator. In contrast, tap water contains dissolved minerals and salts, which dissociate into positive and negative ions (like Ca²⁺, Mg²⁺, Cl⁻). It is the movement of these mobile ions, not the water molecules, that allows tap water to conduct electricity effectively.
