The main factors in the quality of silicone insulated cables are: conductor resistance, insulation resistance, insulation strength, capacitance and loss, ageing and stability, thermal stability and other six aspects.
1. The conductor is the carrier of the signal or electrical energy transmission, and is the most important determinant of the electrical performance of a silicone insulated cable, and we commonly use conductors such as aluminium, copper-clad steel, copper and tinned copper. When the AC voltage is applied, the core resistance is greater than the DC voltage due to the skin effect and proximity effect, but the difference between the two is very small when the frequency of the electric eye is 50 Hz. Through the inspection of this can be found in the production process of certain defects.
2. Insulation material is also an important quality indicator. Different resistance coefficients due to the material varies, insulation strength, dielectric loss and the performance of the gradual damage shown under the work can be very clear judgment of the quality of a silicone insulated cable. The general requirement is that the edge resistance should be higher than the specified value.
3. Insulation strength refers to the silicone insulated cable insulation structure and insulation materials to withstand the electric field without breakdown damage. Insulation strength can be determined through the voltage test and breakdown test to determine whether qualified.
4. As a parameter indicator, the capacitance and loss factor are generally proportional to the current and capacitance under AC voltage. For ultra-high voltage cable capacitance may reach a value comparable to the rated current, becoming an important factor limiting the cable capacity and transmission distance. The reason for the bad can be identified by the change in capacitance.
5. Aging stability that is under stress (mechanical, electrical, thermal) can maintain stable performance of the stability test. If the product quality is not qualified, it cannot reach the life of the product experimental provisions.
6. Thermal stability is a certain cycle of silicone insulated cable heating after the determination of certain sensitive performance parameters to assess the stability of insulation. Insulation stability test is divided into long-term stability test or short-term accelerated aging test.