What is the difference between low impedance grounding and high impedance grounding? What are their functions?
In short, low impedance grounding means that the grounding resistance between neutral point and ground is between 1 ~ 10 ohm, and high impedance grounding means that the grounding resistance between neutral point and ground is greater than 100 ohm. When a single-phase grounding fault occurs in low impedance grounding, the fault current is large, and the fault line can be quickly cut off through the protection device; When a single-phase grounding fault occurs in high resistance grounding, the fault current is small and the line can continue to run with the fault, so the system needs to be equipped with insulation monitoring devices. Therefore, when there is a demand for uninterrupted power supply in the power consumption area, the power supply terminal should be grounded wITh high resistance or ungrounded, that is, it grounding system.