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What are the common performance indicators of insulating materials

Update:13-10-2020
Summary:

Common insulating materials should firstly have high in […]

Common insulating materials should firstly have high insulation resistance and compressive strength, and can avoid accidents such as leakage and breakdown. Secondly, they should have good heat resistance. In addition, they should have good thermal conductivity, moisture resistance and lightning resistance. Features such as mechanical strength and convenient processing.

The performance indicators of common insulating materials include insulation strength, tensile strength, specific gravity, expansion coefficient, etc.

Insulation withstand voltage strength: The higher the voltage applied to both ends of an insulator such as a nylon rod, the greater the electric field force that the charge in the material receives, and the easier it is to ionize and collide, causing the insulator to breakdown. The lowest voltage at which an insulator can break down is called the breakdown voltage of the insulator. When a 1mm thick insulating material is broken down, the kilovolts of voltage that needs to be applied is called the dielectric strength of the insulating material, or dielectric strength for short. Since insulating materials have a certain degree of insulation strength, various electrical equipment, various safety appliances (electrician pliers, electroscopes, insulating gloves, insulating rods, etc.), various electrical materials, the manufacturer has stipulated a certain allowable voltage, said Is the rated voltage. The voltage it bears during use must not exceed its rated voltage value to avoid accidents.

Tensile strength: the tensile force that an insulating material can withstand per unit cross-sectional area, for example, glass can withstand a tensile force of 1400 Newtons per square centimeter of cross-sectional area. The insulating properties of insulating materials are closely related to temperature. The higher the temperature, the worse the insulation performance of the insulating material. In order to ensure the insulation strength, each insulation material has an appropriate maximum allowable operating temperature. Below this temperature, it can be used safely for a long time, and it will age quickly if it exceeds this temperature.

According to the degree of heat resistance, the insulating materials are divided into Y, A, E, B, F, H, C and other levels. For example, the maximum allowable working temperature of Class A insulating materials is 105°C, and most of the insulating materials in distribution transformers and motors generally used are Class A.

 
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