What happens if the high-voltage grounding wire is not connected to the grounding wire and the three-phase is directly connected to the three-phase suddenly
The three-phase voltage has a phase difference of 120 degrees, which means that the average value of the voltage is only about 70% of the amplitude due to the phase difference; In the power transmission system, three-phase power transmission is often used in high voltage; For example, 10kV or 35kV; Such a system has no ground wire during transmission, but that does not mean there is no current and voltage; Because there is a relative zero potential; The three-phase four wire distribution system you mentioned can transmit electricity as usual if the ground wire is not grounded; But the 220V you usually use is the difference between a live line and a neutral line; Because there is no zero line, this value may have deviation; If the three-phase load is unbalanced and the zero line is not grounded, the zero line potential will rise, which may reach the voltage of electric shock accident; For example, some circuits are grounded through the neutral line, and the neutral line is charged at this time, an accident will occur!
