Overhead transmission lines are an important part of the power system and bear a great deal of responsibility for the transport of electricity. Overhead transmission lines are composed of line towers, conductors, insulators, line fittings, ties, tower foundations, earthing devices, etc. The structure of overhead transmission lines is different for different voltage levels, so how do we identify their voltage levels? The next step is to tell you how to identify the voltage level through the insulator.
The insulators of overhead transmission lines are generally suspended from the conductors and are the only electrical insulators that, to a certain extent, have a direct impact on the operation of the line. Insulators have a variety of glass insulators, ceramic insulators and composite insulators, etc. What is the relationship between insulators and voltage levels?
In fact, it is related to the number of insulators, the more insulators, the longer the line insulator string, the higher the voltage level. Reference can be made to the following table:
Additional note: 60KV lines with no less than 5 pieces, below 35KV with pin insulators.