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Electrical insulators are also called power insulators and overhead insulators. They are widely used in electrical power lines and overhead lines, installed on utility poles or towers to prevent current leakage and act as an insulator.
The material of electrical insulators is different from that of semiconductors or conductors. It can block the passage of electric charges, thus achieving an insulating effect.
Hebei Crown Wealth is one of the leading manufacturers of electrical insulators in China. If you want to buy high-quality electrical insulators for your electrical lines, please contact us and get a free quotation. We can also design and provide OEM and ODM production according to your requirements.
Types of Electrical Insulators – Ultimate Guide
According to statistics on electrical accidents, many people have lost their lives due to contact with live conductors. These shocking statistics include workers in electrical installations and passers-by. These accidents could have been avoided by using electrical insulators.
If you are managing a high voltage power project, the installation and use of overhead insulators is one of your first tasks. Through this guide, we will give you a comprehensive introduction to high voltage power insulators.
What is an Overhead Power Line Insulator?
In simple terms, an electrical insulator blocks the flow of electric charge. The resistance to the flow of charge is so great that even if an electric field passes through them, no current can be conducted. The most prominent characteristic of insulators is their high resistivity. Their resistivity is higher than that of semiconductors and conductors, so electric current cannot pass through them, and they are safer to use.
Material of Electrical Insulators
When buying electrical insulators for overhead lines, you need to understand what material they are made of. Although all insulators can prevent the flow of electricity, their insulating abilities are different.
The materials that have been used to make insulators for the longest time are glass, ceramic, and composite polymers. I will take you through these materials so that you can make a better choice.
1. Glass Insulator
Glass is considered to be the oldest material used for electrical insulators. Although it was later replaced by porcelain, glass insulators are still in use today.
Because glass uses an annealing process, the resistivity of glass insulator is higher than that of ceramic insulator, while the coefficient of thermal expansion is low.
This means that even when the current transmitted is large, the glass insulator can maintain good insulation. The glass insulator is not easily affected by external factors and has excellent thermal properties.
Due to glass is transparent, you can see the bubbles and impurities inside more intuitively. Choose insulators of better quality. Glass material has high tensile strength and a long service life. It can be used continuously for many years, saving your maintenance costs.
Glass insulators are less expensive than porcelain and composite polymer insulators.
2. Porcelain Insulators
Porcelain is the most preferred material for making insulators and it is popular for many reasons. Porcelain insulators are made of clay, quartz and aluminum silicate. They have a smooth glaze on their surface, which is dense and can effectively isolate humid air and prevent corrosion.
As one of the best raw materials for manufacturing porcelain, the detection of bubbles and impurities is particularly strict, and no holes or cracks are allowed, which helps ceramic insulators maintain a high resistivity.
Porcelains have high dielectric strength, up to 60kV/CM.
Since ceramics are made of raw materials such as clay, they have strong plasticity and can be easily cast into any shape, while glass requires high-temperature burning and has too high a technical content. Porcelain insulators can adapt to various environments. Unlike glass, the interior of ceramic will not be damaged by temperature changes.
3. Polymeric Insulator
The polymeric insulator is also called a composite insulator, composed of epoxy resin, glass fibers and rod-shaped polymer.
The rods are secured at both ends with galvanized steel and have polymer coatings including rubber, epoxy, ethylene, polytetrafluoroethylene, and ethylene-propylene monomer.
Polymeric insulators are characterized by light weight and easy transportation. They are suitable for transmission environments with low cable loads. The composite material makes it not break or damage.
Polymer insulators also have high tensile strength and flexibility, making them your best choice for areas with harsh environments.
Each insulator material has advantages and disadvantages, which means the best insulator is the one that meets your needs and is suitable for your project.
Any insulator must meet parameter requirements, which include:
- High mechanical strength
- High resistance
- The insulator body is free of impurities and bubbles
- No holes or cracks
- Strong tensile strength
Types of Electrical Insulators
There are six main types of power insulators. I will take you through them in detail.
1.Pin Insulator
Pin insulators are usually used for 25kV~44kV cables to support and protect low voltage cables. Each insulator can be used to transmit 11kV voltage wires.
Even if the outside of this insulator is exposed to rain, the inside can remain dry to prevent leakage.
There is a groove on the top of the insulator to fix the wire, which is easy to install.
Advantages of Pin Insulators
- Lower cost than other insulators.
- Easy to install.
- Effectively support the conductor.
Disadvantages of Pin Insulators
Only applicable to low voltage transmission lines below 50kV.
2.Strain Insulator
The strain insulator (Also called a tension insulator) is used to hang wires and withstand strong pulling forces. Such areas include dead ends and river endings. The design of the strain insulator can increase its mechanical strength and dielectric properties, and it is suitable for high-voltage transmission lines.
3.Stay Insulator
A stay insulator is a type of tension insulator. They are widely used in medium and low voltage lines, such as rural roads.
4.Shackle Insulator
Shackle insulators are usually used in low voltage circuits, have lower capacity, and can be connected horizontally or vertically. They are a substitute for strain insulators.
5.Suspension Insulator
If your project is high voltage wire transmission, then the suspension insulator must be your best ideal insulator, which is very suitable for the insulation of high voltage lines.
The suspension insulator can withstand a high voltage of 400kV. It consists of multiple porcelain plates arranged in sequence, with a wire suspended at one end and the other end connected to an electric tower or utility pole.
Advantages of Suspension Insulator
- If one insulator is damaged, you can replace it, and it won’t affect the other insulators.
- Can adapt to high voltage transmission.
- Easy installation.
- Used with towers to provide lightning protection.
- High mechanical strength, not easily damaged.
6.Post Insulator
Post insulators can be installed on utility poles. Its top is made of a galvanized steel sheet with two holes for fixing.
Characteristics of Electrical Insulators
The insulators manufactured by Hebei Crown Wealth have some special features.
Lightweight – Using a high quality composite support, they are easier to install and safer than most porcelain insulators.
High mechanical strength – Special structure can withstand strong physical shock, after multiple shock tests and vibration tests
High pressure resistance – It can operate stably at voltages from 11kV to 500kV and is suitable for all types of power transmission systems.
Rugged – Long service life and low maintenance cost.
Customizable – Provide OEM and ODM production.
Need to Consider Factors When You Choose Electrical Insulators
Different types of insulators have different properties, and understanding several factors can help you choose the best insulator.
- The voltage transmitted by the conductor
- The distance between the two levels, you need to check if they are long enough
- Choose the right insulator material
- Resistivity of insulator
- Temperature, rain, snow, humidity and other factors will affect the performance of the insulator. Choose the right insulator according to the environment where you live.
- The cost of the insulators may not sound like a decisive factor, but cheap insulators may have quality issues. To ensure your safety, please confirm with the manufacturer and check the price and quality of the insulators.
Electrical Insulator Manufacturers: Hebei Crown Wealth
Where can you find the electrical insulator you want? We provide you with a one-stop solution. You only need to provide the specifications or drawings of the insulators, and we can deliver them according to your requirements.
We have our own factory and manufacture in strict accordance with international standards, so our products are of good quality.
Frequently Asked Questions
What are Electrical Insulators?
Electrical insulators are also called power insulators and overhead insulators. They are widely used in electrical power lines and overhead lines.
What are the types of electrical insulators?
According to the material, there are glass insulators, porcelain insulators, and polymer insulators.
According to voltage, there are low-voltage insulators, medium-voltage insulators, and high-voltage insulators.
According to the purpose, there are pin insulators, stay insulators, post insulators, suspension insulators, shackle insulators, and strain insulators.
What are the Characteristics of Electrical Insulators?
- Lightweight
- High mechanical strength
- High pressure resistance
- Rugged
- Customizable
