What is the function of insulators?

The main function of insulators is to firmly support and fix the current carrying conductor, forming a good insulation between the current carrying conductor and the ground. Insulators (commonly known as porcelain bottles) are composed of two parts: a porcelain part and metal fittings, which are bonded with cement adhesive in the middle. The porcelain part ensures good electrical insulation strength of the insulator, and the metal fittings are used to fix the insulator.
Tempered glass insulators are a special type of insulation control that can play an important role in overhead transmission lines. Insulators play two basic roles in overhead transmission lines, namely supporting conductors and preventing current from returning to ground. These two important roles are that insulators can achieve good insulation effects.
Insulators not only bear the weight of mechanical loads, wires, and metal accessories, but also must withstand wind loads, snow loads, wire galloping, and impact loads caused by improper operation during transportation and installation under adverse weather conditions, bearing significant loads. From an electrical perspective, insulators not only need to insulate the wires from the ground, but also must withstand overvoltage surges caused by lightning and switching operations.
When flashover occurs due to voltage impact, local overheating will not cause the tempered glass body of the insulator to burst. All external factors will have an impact on the performance of insulators, therefore, higher requirements are also put forward for the design of glass insulators. The design requirements of glass insulators require strict treatment, with a strict design and practical foundation.
Extended information;
According to different classification standards, insulators can be divided into high and low voltage insulators, suspension insulators, anti pollution insulators, and sleeve insulators according to their structure. These four types of insulators are applied in different fields with different usage restrictions and conditions. The commonly used insulators in overhead lines include pin insulators, suspension insulators, porcelain cross arms, butterfly insulators, rod insulators, and tension insulators.
In addition, the technical standards for insulators also require various electrical, mechanical, physical, and environmental conditions tests to be conducted on insulators based on their models and usage conditions, in order to verify their performance and quality. Insulator fittings will not produce obvious corona discharge under operating voltage, because insulators are widely used devices, and their connection fittings are also required to be interchangeable.
There are two types of electrical performance faults of insulators: flashover and breakdown. The flashover and breakdown electrical performance faults target different faults and have different methods of occurrence. Flashover occurs on the surface of the insulator, where burn marks can be seen and insulation performance is usually not lost. Breakdown occurs inside the insulator and is discharged through the ceramic body between the iron cap and the iron foot. Although there may be no marks on the surface, insulation performance has been lost.