Types of Insulators and Their Applications

An insulator gives support to the overhead line conductors on the poles to prevent the current flow toward earth. In the transmission lines, it plays an essential role in its operation. The designing of an insulator can be done using different materials like rubber, wood, plastic, mica, etc. The special materials used in the electrical system are glass, ceramic, PVC, steatite, polymer, etc. But the most common material used in the insulator is porcelain and also special composition, steatite, glass materials are also used. This article discusses an overview of different types of insulators and its working.

Types of Insulators

These are classified into different types based on their rating which includes the following. These are used in transmission & distribution system where each insulator consists of several insulating discs. If one disc used 11kv voltage then the remaining discs use 66kv voltage.

• Pin Insulator
• Suspension Insulator
• Strain Insulator
• Shackle Insulator
• Post-Insulator
• Stay Insulator
• Disc Insulator

Pin Insulator

This kind of insulator is used in distribution systems. The voltage capacity of this insulator is 11kV. It is designed with a high mechanical strength material. These are connected in vertical as well as horizontal positions. The construction of this insulator is simple and needs less maintenance as compared with other types. Please refer to this link to know more what a Pin Type Insulator is: Construction, Causes & Applications.

Suspension Insulator

This also called disc insulator and the designing of these insulators can be done using materials like porcelain or glass. The voltage capacity of suspension insulator ranges from 11 kV to 765 kV. It is used in overhead transmission lines by providing more flexibility. It uses various discs based on the level of voltage. It is connected by using the steel tower so it needs more height to support all the discs.
These insulators are most helpful compare with other insulators because; if one disc in the insulator gets damage then remaining all the discs will work properly. So the damaged disc can be replaced with others. Please refer to this link to know more bout what Suspension Insulator is: Construction, Working & Its Types

Strain Insulator

This is similar to suspension type insulators because it is used in an overhead transmission system but its specifications and working are somewhat different. The voltage capacity of the strain insulator is 33kV. Mostly in the transmission line, it is placed in bend otherwise arm place. Please refer to this link to know more bout Strain insulator and its Working

Shackle Insulator

These insulators are small in size, used in overhead distribution systems. The connection of this insulator can be done by using a metallic strip. The voltage capacity of this insulator is 33 kV and works in the positions of bend or circular turn. At present, these insulators are used as strain insulators but they are used in less voltage distribution lines. Shackle insulators are used in a vertical position or horizontal position. These are connected to the pole using bolt otherwise cross arm. Please refer to this link to know more: What is Shackle Insulator: Working & Its Applications.

Post-Insulator

These insulators are used in the substations because it is appropriate for different voltage levels. It is arranged in a vertical position and protects transformers, switchgear and other connecting devices. The mechanical strength of these insulators is strong.

Stay Insulator

These insulators are rectangular, used in the distribution lines. These are available in small size when compared with other types. The arrangement of these insulators can be done among the line conductor & earth. These insulators work like protecting devices that protect from sudden faults otherwise voltage change happens suddenly.

Disc Insulator

The disc insulators provide a cost-effective solution for medium & low polluted environments and these are designed with high-grade raw materials. These insulators are well-known in the broad market because they are mostly used in transmission & distribution lines. The applications of these insulators include transmission lines, industrial & commercial because they have high efficient features like less corrosion, robust design; it supports conductors, used for insulation in cables and electrical wiring and maintains high voltage within high loads. Please refer to this link to know more: What is Disc Insulator: Types & Its Applications.

Other Types of Insulators

The other types of insulators include the following.

Polymer Insulator

These insulators are composed of fiberglass rod and enclosed with polymer weather sheds. These are low in weight compare with porcelain type while giving better power. These insulators are designed with PTFE, silicon rubber, EPDM and EPM.

Glass Insulator

Glass insulators started being used in the 18th century for telegraph and telephone lines, which were then, replaced by ceramic and porcelain types in the 19th century. To overcome this, toughened glass types were introduced, which became popular due to their longer lifespan.

Long Rod Insulator

These are porcelain rods including weather sheds & metal end fittings at outside. In this insulator, there is no metal part among the units, which assists to raise their strength. These are applicable at both tension and suspension locations.

Properties of Insulators

The properties of an insulator are mechanical and dielectric strength is high, insulation resistance is high to prevent leakage current. Insulator materials must be free from cracks, impurities and nonporous. The properties of an insulator are mechanical and dielectric strength is high, insulation resistance is high to prevent leakage current. Insulator materials must be free from cracks, impurities and nonporous.

Applications of Insulators

The applications are

• These are used in circuits, electric boards to ensure safety techniques.
• These insulators protect the materials from electricity and heat.
• Plastic and rubbers are used to manufacture daily products.

FAQs

1). What is the function of an insulator?

An insulator is one kind of material where the internal electric charge of this does not run freely; insufficient electric current will run through it in the power of an electric field.

2). What are the types of insulators are used in overhead transmission lines?

They are pin, suspension, strain, shackle, and stay.

3). What are the examples of an insulator?

They are paper, plastics, rubber, Styrofoam, glass & dry air

4). What is insulation breakdown?

Once breakdown voltage is applied to insulator then it will become conductive so this is known as insulation breakdown.

Thus, this is all about different types of insulators. These are used in transformers because, in electrical systems, these are the most important parts. We cannot get a secure amount of current without using transformers to use in offices, homes. Here is a question for you, what are the most commonly used insulating materials?