What Is a Ground Line?

The ground wire is a wire that is connected to the ground, connected to the housing, or connected to a zero reference potential in an electrical system or electronic equipment. On general electrical appliances, the ground wire is connected to the casing to prevent electrical shock caused by the electrical insulation damage to the casing. Ground wire is short for grounding device. The ground wire is divided into working ground and safety ground. Protective grounding to prevent people from getting an electric shock when using home appliances and office electronic equipment is a kind of safety grounding protection wire.

The ground wire is a wire that is connected to the ground, connected to the housing, or connected to a zero reference potential in an electrical system or electronic equipment. On general electrical appliances, the ground wire is connected to the casing to prevent electrical shock caused by the electrical insulation damage to the casing. ^[1]

The longer of the three feet is grounded and can be referred to as the ground 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, in consideration of the safety of the user, the grounding pin is consciously designed to be several millimeters longer than the conductive pin. This is because when the three-pin plug is inserted, the ground pin first contacts the ground wire in the socket, which can form ground protection first, and then turn on the power. On the other hand, when the three-pin plug is pulled out, the conductive pin is first connected to the conductive end in the power socket. Separate and disconnect after grounding. If the metal casing of a household appliance is charged due to damage to the insulator, etc.

Ground wire is short for grounding device. The ground wire is divided into working ground and safety ground. Protective grounding to prevent people from getting an electric shock when using home appliances and office electronic equipment is a kind of safety grounding protection wire. Safety grounding generally includes lightning protection grounding and electromagnetic radiation grounding. ^[2]

In the TN-S power supply system, the residential electrical load is generally different, that is, the three-phase load is unbalanced.

Literature ^[4] used the electrical geometric model method to study the relationship between the installation position of the overhead ground wire, the number of lightning flashovers, and the discharge current of the arrester, and proposed lightning protection grounding measures for the overhead ground wire, and finally proposed engineering applications. The following conclusions were reached: ^[4]

(1) The overhead ground line of the subway can reduce the number of lightning flashovers of the contact network, and the effect is more obvious when the wire height is higher. It is beneficial to use the overhead ground line for lightning protection in subway projects;

(2) There is not much difference between the total number of flashovers of the contact net when the overhead ground wire is installed above the conductor and when it is installed at the top of the pillar.

(3) The overhead ground wire has a shunting effect on the operating impulse current of the metal oxide arrester with a series gap for protective insulators. The overhead ground wire is installed at the height of the top of the pillar to be less than 0.1 times / 100km · a (with 40 Thunderstorm day meter) is used to verify the value of the indicator. The recommended installation position is 1m higher than the wire.