The family only needs a total grounding wire (mostly the three-phase five-wire power supply system, the grounding wire refers to the protection zero wire or the PE wire). If you are a new house, the home distribution box should be There is a total PE line connected to the terminal block. You have to split the two lines and take two lines from the terminal block.
If you are a three-phase four-wire power supply system, you can repeat the grounding of the working zero line of the incoming line (the grounding resistance is not more than 10 ohms, of course, the smaller the better), and then a protective neutral line is taken from the grounding pole. .
The uppermost hole of the three-hole socket should be connected to the protective neutral wire. The protective neutral wire is connected to the metal casing of the electrical appliance through the three-phase plug. If the electrical appliance is charged due to insulation problems, then a single-phase short circuit is formed, thereby forming a single-phase short circuit. Actuate the protection device and cut off the power supply to protect your life.
If it is a commercial house, naturally there is a grounding wire to enter the household, the decoration electrician also understands, the wiring is the simplest. And the general grounding line color is yellow-green two-color, generally more BVR soft lines. Of course, it is also possible to make a ground wire for the BV line.
The ground wire of the family, the phase of the three-phase plug on the wall alone is the ground wire, and some old buildings have no ground wire. It is best to take a look at it. If that phase is wired, it will be right. If it is a factory, the general distribution cabinet has a ground wire. As long as it is connected to the main body of the cabinet, the outside of the building is connected to the underground metal objects (there is a small iron box), some are steel bars, and some are steel bars. If you are a bungalow, you want a ground wire. You can dig a long hole of about 50 cm deep in the house. The channel steel or iron plate is placed in the bottom of the pit to weld steel bars or steel bars. After connecting, pull out the pit. The wall is fixed and the cable is used if needed indoors.
If it is a self-built house in the countryside, the main business in order to save money, and the concept is not, there is no grounding line. Of course, if it is done, it is the best, just like the landlord said, looking for an open space outside, buying root galvanizing Angle iron or galvanized steel pipe can also be broken into the ground, and then welded to the indoor distribution box (this is the soil method. According to the correct method at the atlas, it should be grounded, 3 angle iron is one Group, one pitch of five meters, 2.5 meters into the ground, grounding resistance, <1 ohm according to lightning protection requirements, <4 ohms for transformer neutral line.)