Insulators are widely used in power distribution devices, transformers, various electrical appliances and transmission lines in power plants and substations. It is used to support and fix the bare current carrying conductor and insulate the bare conductor from the ground, or to insulate the current carrying conductors at different potentials in devices and electrical equipment from each other. Therefore, the insulator must have sufficient electrical insulation strength, mechanical strength, heat resistance and moisture resistance. According to the installation location, insulators can be divided into indoor type and outdoor type.

According to the structure and use, it can be divided into support insulator and bushing insulator. 

Post insulator

Post insulators are divided into indoor type and outdoor type. Indoor post insulators are widely used in power grids with various voltage levels of 3 - 110 K.

1. Indoor post insulator

Indoor post insulators can be divided into external glue type, internal glue type and combined glue type.

2. Outdoor post insulator

There are two types of outdoor post insulators: pin type and solid rod type. It is mainly composed of insulating porcelain bodies 2 and 4, cast iron web 5 and mounting foot 1 with flange plate.

Bushing insulator

Bushing insulator is called bushing for short. Failure tube insulators can be divided into indoor type and outdoor type according to their installation location.

1. indoor tube failure insulator

According to the characteristics of current carrying conductor, indoor bushing insulator can be divided into the following three types: current carrying conductor with rectangular section, current carrying conductor with circular section and bus type.

The first two bushing current carrying conductors and their insulating parts are made into a whole. When in use, both ends of the current cutting conductor are directly connected with the bus. The bus type bushing itself does not have current carrying conductor. When installed and used, the original current carrying bus is installed in the rectangular window of the bushing.

2. outdoor tube insulator

The outdoor bushing insulator is used to connect the indoor current carrying conductor and the outdoor current carrying conductor in the power distribution device, such as the outgoing end of the line or the current carrying conductor part of the outdoor electrical appliance led out from the inside of the grounding shell. Therefore, the insulation at both ends of outdoor bushing insulator shall be designed according to indoor and outdoor requirements.