Cables are products used to transmit electrical energy, information and realize the conversion of electromagnetic energy. When purchasing cables, you need to consider whether the quality of the ABC Cables can meet your needs. The following are several important indicators that need to be paid attention to when purchasing wires and cables, which can be used to measure the quality and performance of wires and cables. Help you make better choices.
- Measurement of wire DC resistance:
The conductive core of the wire and cable mainly transmits electrical energy or electrical signals. The resistance of the wire is the main indicator of its electrical performance. When the AC voltage is applied, the wire core resistance is larger than that of the DC voltage due to the skin effect and proximity effect, but the difference between the two is very small when the electrical frequency is 50Hz. Through this The inspection can find defects such as wire breakage or part of the single wire breakage, wire cross-section does not meet the standard, and the length of the product is incorrect.
- Insulation resistance test:
Insulation resistance is an important indicator that reflects the insulation characteristics of wire and cable products, and is closely related to the product’s dielectric strength, dielectric loss, and the gradual deterioration of insulating materials under working conditions. It is generally required that the insulation resistance be higher than the specified value.
- Measurement of capacitance and loss factor:
In EHV cables, once the capacitance current reaches a value comparable to the rated current, it will become an important factor limiting the cable capacity and transmission distance. Therefore, the capacitance of the cable is also one of the main electrical performance parameters of the cable. Through the measurement of capacitance and loss factor, various insulation degradation phenomena such as insulation damp, insulation layer and shielding layer falling off can be found.
- Dielectric strength test:
Dielectric strength refers to the ability of the insulating structure and insulating materials to withstand the action of an electric field without breakdown. In order to ensure the safe operation of the product, all insulation types of wires and cables generally need to undergo a dielectric strength test. Through the test, the reliability of the product operating under the working voltage can be tested, serious defects in the insulation can be found, and some shortcomings of the production process can also be found.
- Thermal aging and thermal stability test:
The aging test is a stability test of whether the performance can be kept stable under the action of stress (mechanical, electrical, thermal). Put the test product in an environment with a certain value higher than the rated working temperature, and observe its performance change at a higher temperature T; the thermal stability test is that the cable is heated by a current and also bears a certain voltage. After a certain period of heating, some sensitive performance parameters are measured to evaluate the stability of the insulation.
