The Role of Electrical Power Cable Shielding Layer
Ⅰ. Insulation layer of electrical power cable
Generally, the outermost layer of the electrical power cable is rubber or rubber composite sheath. The function of this layer is to insulate and to protect the cable from damage.
The cable is classified into high voltage or low voltage. If it suits high voltage, there will be a layer of resin-like filler inside, which is used for insulation. In high voltage cables, this layer is the most important part of insulation. Low-voltage cables do not have this layer. Then there will be something like ribbon wrapped inside, which is to fix each core of the cable and fill the gap in the cable.
Ⅱ. The role of power cable shielding layer
As for the shielding layer, there are two cases. The functions of the shielding layer of the electrical power cable are as follows:
1. Because the current through the electrical power cable is relatively large, a magnetic field will be generated around the current. In order to put no effect on other components, the electromagnetic field can be shielded in the cable by adding a shielding layer.
2. It can be protective by grounding. If the cable core is damaged, the leaked current can flow into the grounding grid along the shielding layer to play a role of protection.
If it's a control cable, there is little difference with electrical power cable. It's just that in many places, especially the control cable of a computer system, the shielding layer here is used to shield from external influences, because its own current is very weak, and it is very sensitive of external electromagnetic fields.