The role of the shield of the power cable

The outermost layer of wire and cable is generally a rubber or rubber composite sleeve. The role of this layer is insulation. It also protects the cable from damage.

The cable is divided into high-voltage and low-voltage cables. If it is high pressure, there will be a layer of resin-like filler inside. This is an insulation. In high-voltage cables, this layer is the most important part of insulation. There is no such thing as low pressure. Then there will be something like a ribbon wrapped around it. This is to fix every cable core and fill the gaps in the middle.

As for the shielding layer, there are two cases in which the role of the shielding layer of the power cable is as follows:

1, because the power cable through the current is relatively large, the current around the magnetic field will be generated, in order not to affect other components, so add shielding layer can shield this electromagnetic field in the cable.

2, can play a certain degree of grounding protection, if there is damage inside the cable core, leakage of current can be along the shielding of laminar flow such as grounding network, play a role in security protection.

If it is a control cable, there is no difference, but in many places, especially the control cable of a computer system, the shielding layer is used to shield external influences, because the current itself is very weak, and it is very afraid of the influence of the external electromagnetic field.