The conductive wire of the wire and cable mainly transmits electrical or electrical signals. The resistance of the wire is the leading indicator of its electrical performance.
When the AC voltage is applied, the core resistance is larger than that of the DC voltage due to the skin effect. However, when the frequency of the electric eye is 50Hz, the difference is small.
Insulation resistance reflects the insulation characteristics of wire and cable products, an important indicator, with the development of the electrical strength, dielectric loss, and insulation materials in the working state of the gradual deterioration of the relationship are closely related—the current wire and cable insulation resistance measurement.
In a cable with AC voltage, there is a current flow, when the voltage amplitude and frequency of a certain, the size of the capacitor current are proportional to the cable capacitance (Cx).
For EHV cables, the current of this capacitor may reach a value that can be compared to the rated current, making it an important factor in limiting cable capacity and transmission distance.