Function of cable shielding layer

1, because the power cable through the current is relatively large, the current will produce a magnetic field, in order not to affect other components, so add shielding layer can be shielded in the electric field cable.
2, can play a certain grounding protection, if the cable core wire breakage, leakage out of the current can be shielded laminar flow such as grounding network, play a role in security.