Why Electrical Insulators Don’t Conduct Electricity? Answered!


You can experience electrical shocks in different situations like opening the car doors or operating an appliance in your home. This usually happens when in contact with conducting materials, but it can’t happen to you when using non-conducting materials like wood.

This is due to the nature of wood, an electrical insulator, where the current doesn’t pass through it like conducting materials. Electrical insulators have different types and many applications in most fields.

Why Do Electrical Insulators not Conduct Electricity?

Because electrons of insulators have to get excited to conduct electricity, the energy required to excite the insulators’ electrons is very high. Therefore, the electrons don’t get excited, so the insulators can’t conduct electricity due to this energy gap between the conduction and the valence bands.

What Are Electrical Insulators?

The electrical insulators, or the insulators in general, are the substances or materials which don’t allow or resist the current to pass through them. Insulators are mostly found in solid materials in nature; they have wide usage in different fields and systems. 

In addition to not passing any electricity, they don’t pass any heat energy. The main difference between the insulators and the conductors is that the insulators have higher resistivity. Insulators have many examples like micawoodglassquartz, and cloth.

Another benefit of insulators is the protection; they provide protection against sound, heat, and flow of electricity. These features of insulators are due to the nonpresence of free electrons in insulators; therefore, they can not pass energy. 

What Are The Applications of Electrical Insulators?

Electrical insulators obstruct the passage or the flow of electrons through them; therefore, you can find electrical insulators widely used in high voltage systems and circuit boards. In addition, electrical insulators are used to protect and cover electrical cables and wires. 

You can also find electrical insulators in electrical appliances and equipment, where they are used to prevent the probability of high voltages. High voltages can cause damage to the electronic pieces in these devices. 

The flexible type of electrical insulator is used to cover and coat electric wires and cables, known as insulated wires. The usage of insulators is very important, especially when wires are going to be close to each other.

Electrical wires, when in contact, can cause short circuits, fire mishaps, and cross-connections. Insulators can also be used in coaxial cables, where to stop the wave reflections of EM support need to be placed at the center of the conductor.

Electrical insulators are made of materials that resist the movement of electrons through them. Electrons are not able between atoms; therefore, insulators can not transfer electric charge.

Insulators can have other applications also where different types of insulators are used, for example, thermal insulators and sound insulators:

  • Sound Insulators
    They control noise levels because they are great for absorbing noise and sound. This can be applied in conference halls and buildings to control noise levels; in some cases, they can be noise-free. 
  • Thermal Insulators
    They prevent the movement or the flow of heat from one place to another, which can be very useful in making thermoplastic bottles. They can also be applied in fireproofing the walls and ceilings.

What Are the Types of Insulators?

Disc Insulator

These insulators are suitable for medium and low polluted environments as they are made of raw materials of good quality. Disc insulators are used in transmission and distribution lines; in addition, they are used in supporting electrical wires conductors and insulation.

Pin Insulator

These insulators are designed from strong materials with a high voltage capacity of 11kV; they can be connected horizontally or vertically. This type of insulator requires low maintenance, and its construction is simple.

Post Insulator

These insulators have different levels of voltages; therefore, they are suitable for substation applications and are arranged in a vertical direction. The main use of these insulators is the protection of transformers, switchgear, and other connecting devices. 

Shackle Insulator

These insulators are small and can be found mainly in distribution systems (overhead). Connecting these insulators is done using a metallic strip. They operate in the position of circular bends or circles; in addition, they have a high voltage capacity of 33kV.

Stay Insulator

Stay insulators are known for their rectangular shape and small size; they are used in distribution systems. They are arranged in line conductors, and within the earth, these insulators’ main job is to protect electrical devices during voltage fluctuations from unexpected jerks.

Strain Insulator

These insulators can be found in transmission systems (overhead), with a voltage capacity of 33kV. They are positioned in a bent position or arm place; despite having similar applications as suspension insulators, they work differently and have different specifications. 

Suspension Insulator

This insulator has a wide range of voltage capacities ranging from 11kV to 765kV, which introduces flexibility when used in transmission lines (overhead). In addition, they have better efficiency when compared to other types of insulators. Because the discs continue to work properly even if one disc gets damaged, the damaged disc can be replaced with another. 


What is The Difference Between Electrical Conductors and Insulators?

Conductors Insulators
Current can flow through them Current can not flow through them
Their surface can carry electric charge Their surface can not carry electric charge
When kept in magnetic field they can’t store energy When kept in magnetic field they can store energy
Conductors have a very high thermal conductivity Insulators have a low thermal conductivity
Conductors have low resistivity Insulators have very high resistivity
Used in designing electrical equipment Used in insulating electrical qeuipment
Mercury, Aluminum, Silver Wood,  Ceramic, Papar

What Are Electrical Conductors?

The electrical conductors, or the conductors in general, are the substances or materials which allow or let the current pass through them. The main reason for the passage of electricity inside conductors is the free movement of electrons between atoms.

In addition to the passage of electricity inside conductors, they allow the passage of light and heat between different sources. Conductors have many examples like animals, humans, metals, and the earth. This is why you can get an electric shock because our body can act as a conductor.

You can find free electrons located on the surface of the conductors, which are responsible for the passage of electric current. This differs between insulators and conductors; insulators lack free electrons on their surfaces. 

What Are The Applications of Electrical Conductors?

Electrical conductors like copper, silver, and gold are used in almost every electrical cable and wire; in addition, they are used in soldering electronic components and joining them. Furthermore, liquid electrical conductors are used in batteries of large capacity. 


To sum up, electrical insulators can not pass any electricity through them due to the absence of free electrons on their surface. As a result, they resist the flow of current through them and prevent the movement of electrons between atoms. 

The energy gap between energy bands in electrical insulators is very high, and since the electrons have to be excited to transfer energy, this doesn’t happen in electrical insulators. 

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