Insulation materials are graded. The insulation level is closely related to the temperature resistance of insulation materials. The higher the temperature is, the worse the insulation grade and performance of insulation materials. Therefore, insulation materials have a temperature proof performance standard, and they can be used safely within the standard.
The grade of insulating material is generally divided into 3 kinds:
One, the insulation level of gas insulation material: air insulation, nitrogen insulation and six fluoride sulfur insulation, general gas insulation has strong insulation resistance below discharge voltage, and if it destroys insulation, it can also automatically restore. Compared with liquid insulation and solid insulation.
Its disadvantage is that the yield value of the insulation grade is low. So the demand for it is:
1. has very good free field strength and breakdown field strength, and after breakdown its insulation performance can quickly, automatically restore. It belongs to elastic breakdown.
2. chemical properties are stable, inert, no corrosiveness, no poison.
3. does not burn without explosion is not easy to decompose because of the discharge effect.
4. high temperature stability, large capacity, good thermal conductivity and good flow performance.
5. easy to make and low cost.
6. the liquefying temperature is low.
Two, the insulation grade of liquid insulating material: there are two kinds of liquid insulating materials with mineral insulating oil and synthetic insulating oil to separate the liquid of electric potential. It can also be called insulating oil. It can replace gas to fill the gap between the internal and the poles of the solid material to improve the insulation performance and improve the heat dissipation of the equipment. For example, in the oil immersed paper insulation power cable, it not only improved the insulation performance obviously, but also enhanced the strong heat dissipation function. In the capacitor, it increased its insulation performance and enhanced the energy storage per unit volume. In addition to the switch in the switch, the main thing is that it can play the role of arc extinguishing.
Three, insulation grade of solid insulating material: it is divided into organic solid insulating material: insulation binding tape, insulating paper, insulating pipe, insulating adhesive and so on. It is a solid separated from a conductor. Solid insulating materials also require support. Compared with gas and liquid insulating materials, solid insulation materials have higher breakdown strength due to higher density, which is of great significance for reducing the thickness of insulating materials. The insulation resistance, dielectric and dielectric loss of solid insulating materials vary widely. So it can prevent the leakage of electricity too much, and the relative dielectric constant of the solid insulation material is very low only 2 make the insulation capacitance measure very small. The high dielectric constant of high dielectric ceramics is very high, up to thousands.
So it can be chosen according to the different requirements.