The main differences between protective grounding and protective zeroing
Different protection principles Protective grounding is to limit the ground voltage after leakage of equipment so that it does not exceed the safe range. In the high-voltage system, in addition to limiting the ground voltage, in some cases, there is also the role of causing the grid protection device to operate; the protection of the zero is to make the equipment leakage by means of the zero-connecting line to form a single-phase short circuit, and promote the line on the line. The protection device operates and the power to the faulty device is turned off. In addition, in the protected zero-connected grid, the protection neutral and repeated grounding can also limit the ground voltage when the device is leaking.
Scope of application Different protection grounding is applicable to high and low voltage power grids that are generally not grounded. It is also suitable for low voltage power grids that have adopted other safety measures (such as installing leakage protectors). The protection connection is only applicable to low voltages where the neutral point is directly grounded. Grid.
Different line structure If protective grounding measures are taken, there may be no working zero line in the power grid, only the protective grounding line; if the protective zeroing measures are taken, the working zero line must be set, and the working zero line is used for zero protection. The protective zero line should not be connected to switches or fuses. When installing a disconnector such as a fuse on the working zero line, a protective grounding wire or a zeroing wire must be additionally installed.