How to connect the ground wire of three phase electricity? How to do a grounding wire for three phas

As long as the ground wire of the socket is connected, the ground wire connector of the main switch can be connected. This is the ground wire that has been connected. The longer of the three feet is grounded, which can be called the grounding pin, and the other two shorter feet are used to connect household appliances to the circuit, which can be called conductive feet.

When designing the power plug, the grounding pin was consciously designed to be a few millimeters longer than the conductive pin in consideration for the user's safety.

This is because when the three-pin plug is inserted, the grounding pin first touches the grounding wire inside the socket.

In this way, grounding protection can be formed first, and then the power supply can be turned on; Conversely, when pulling out the three-pin plug, the conductive pin is connected to the power socket first.

The conductive end within is separated and disconnected after the grounding pin.

If the metal casing of household appliances is due to insulators.

If the grounding foot is charged for damage and other reasons, the grounding foot will form a grounding short-circuit current, so that the metal shell of the household appliance is grounded and discharged to the ground, so that people will not be electrocuted and play a role in safety protection.

Friends, the leakage phenomenon should be eliminated, only to consider the grounding wire (E), do not connect the fire, zero wire, you can use a square copper core wire, one end is connected to the shell of the laboratory bench, and the other end is connected to the ground wire (E) binding post of the wall socket, if the socket does not have a ground wire, you can connect a ground wire from the power distribution box.

It is connected to a dedicated grounding wire, and if not, you can install it yourself.

The three-phase wire should also have a place to ground.

There is a special three-phase short-circuit grounding wire.

The three-phase short-circuit grounding wire is a combined grounding wire, which is composed of three short-circuit grounding rods, three-phase grounding wire, and a grounding clip, which is mainly used to prevent sudden calls from equipment and lines and eliminate the induced voltage.

Three-phase four-wire system 380V electrical equipment protection grounding method: three-phase four-wire system 380V electrical equipment grounding protection is to connect the equipment shell to the ground or the equipment shell to the grounding line. The equipment shell cannot be connected to the earth or the motor without a grounding wire, and only a leakage protector can be installed, and the neutral wire cannot be used for grounding protection.

Three-phase four-wire 380V grounding protection leakage method: Protective grounding refers to connecting the uncharged metal part of the electrical device with the grounding device under normal conditions to prevent the part from suddenly being charged in the case of a fault and causing harm to the human body. All single-phase and three-phase electrical equipment with metal shells need to be protected and grounded.

Wiring method. When the three-phase alternator supplies power to the outside, the ends of the three groups of coils X, Y, and Z are connected together, and a line is drawn from the connection point, which is called the neutral line, also called the neutral wire. Then draw a wire from the other end of the coil winding, A, B, and C. In this way, a three-phase four-wire system (three live wires and one neutral wire) is formed, and this connection method is called the star connection method.

Because the three-phase four-wire power supply can supply two different voltages of 220V and 380V at the same time, it is widely used. The star connection is represented by y, which is also called the y connection. If the middle line is not drawn, the power supply to the outside with three wires is called a three-phase three-wire system.

The shell of the equipment cannot be connected to the earth or the motor without a grounding wire, and only a leakage protector can be installed, and the neutral wire cannot be used for grounding protection.

In a three-phase electrical system, the main function of the ground wire (also known as the ground wire or ground cable) is to ensure the safe operation of electrical equipment. The ground wire is connected to the metal casing of the electrical equipment to prevent electric shock accidents. The grounding wire is usually a green (or green with yellow stripes) wire that connects to the metal casing of the electrical equipment and connects to the ground, forming a grounding system.

In a three-phase electrical system, the ground wire is connected as follows:

1. The grounding wire should be connected to the metal shell or grounding terminal of the electrical equipment. This helps to ensure that the metal casing of the equipment is not energized in the event of an internal failure, thereby reducing the risk of electric shock.

2. In the distribution box, the grounding wire should be connected to the grounding busbar. The grounding busbar is a metal strip that is used to connect all the grounding wires together to form a unified grounding system.

3. The grounding busbar should be connected to the ground, and the grounding electrode (such as copper grounding rod) is usually buried deep into the ground to form an effective grounding system. The grounding electrode needs to have good conductivity and corrosion resistance to ensure the long-term reliability of the grounding system.

When installing and maintaining a three-phase electrical system, it is important to ensure that the ground wire is properly grounded to ensure the safe and reliable operation of electrical equipment.

Knowledge of phase wire, neutral wire, and grounding wire.

For household electricity, the standard single-phase user has three wires, phase line L, neutral line N and grounding wire PE, neutral line N and phase wire of the same cross-section, grounding wire PE is square millimeters, double colorThe protection of household electricity is completed by the wiring of the socket plug, and the wiring principle of the plug and socket is: the left zero and the right phase are grounded.

It is the plug-in connection between the shell and the plug of the household appliance, the plug-in connection between the grounding wire (PE) and the socket from outside, the zero wire (N) from the outside is plugged in to the left, and the phase wire from the outside is plugged in to the right. The shell of the household appliance is reliably connected to the earth to realize the safety protection of electricity.

Ground and neutral wires cannot be mixed:

1. The neutral wire of the neutral line and the transformer is directly connected, and the live wire directly forms a loop, without voltage drop loss;

2. The grounding resistance of the neutral line and the neutral wire is very high, the grounding resistance of the transformer below 100kva cannot be higher than 10 ohms, and the grounding resistance of the transformer above 100kva cannot be higher than 4 ohms;

3. The grounding wire is connected with the neutral line and the neutral wire at the transformer, and it will be independent in the future, and the grounding will be repeated to the distribution box, but the grounding resistance is only 30 ohms or less.

4. The cross-sectional area of the neutral wire and the live wire are the same, and the same current should be passed, while the ground wire is generally a square millimeter, and a larger current cannot be passed, so the grounding wire cannot be used as the neutral line;

5. Users who do not have a grounding wire, household appliances are not grounded, and they can't get the grounding wire by themselves (if they are unqualified, the harm is greater), and they can't use the zero wire as the grounding wire (when the three-phase current is unbalanced, the zero line is live, and the shell of the household appliance is also pointed, and the shell of the household appliance is directly connected to the thermal power when the zero line is broken, which is more dangerous.) ), which will affect the normal operation of the power system.

6. Users who do not have a grounding wire can install a leakage protector to protect.