All of them.
Grounding wire is directly connected to the earth's line, can also be called a safety return line, when the danger of it will be high-voltage directly transferred to the earth, is a lifeline. Connected to the shell of electrical equipment and other parts of the timely unsafe charge or leakage current due to various reasons out of the line.
In the household electrical equipment due to poor insulation or use of humid environment, will lead to its shell with a certain amount of static electricity, serious electric shock will occur. In order to avoid accidents can be connected to a wire above the metal shell of the appliance, the other end of the wire into the earth, once the appliance leakage occurs when the grounding wire will bring the static electricity into the earth to release, so electrical appliances should be grounded.
In the power system in the grounding wire, is in order to have been blacked out equipment and lines accidentally appeared on the voltage to ensure that the staff of an important tool. According to the provisions of the ministry, the grounding wire must be more than 25mm 2 bare copper wire made. So the switch socket also need grounding wire.
The components of the grounding method can be divided into two parts of the electrical equipment and power distribution system.
One, the grounding part of the electrical equipment
1, grounding body: close contact with the earth and the earth to form an electrical connection or a group of conductors.
2, exposed conductive part: electrical equipment can touch the conductive part. Normal non-electrical, fault may be charged, usually for the metal casing of electrical equipment.
3, the main grounding terminal board: a building or part of a building within a variety of grounding (such as work grounding, protective grounding) of the terminals and equipotential connecting line of the combination of terminals. If arranged in rows, it is called the main grounding terminal row.
4, protective wire (PE): the exposed conductive part of the above, the main grounding terminal board, grounding and power grounding (or artificial grounding) any part of the conductor for electrical connection. For the connection of more than one exposed conductive part of the conductor is called the protective trunk.
5, grounding line: the main grounding terminal board or the exposed conductive part directly to the grounding body of the protective line. For connecting more than one grounding terminal board is called grounding trunk.
6, equipotential connection: refers to the exposed conductive part and the device outside the conductive part of the potential substantially equal to the electrical connection? .
Two, the grounding part of the distribution system
1, phase line (L). The conductor that carries electrical energy and is not normally grounded.
2, neutral (N). Connected to the neutral point of the system, and can play a role in conveying electrical energy conductor.
3, protective neutral (PEN). Both protective line and neutral conductor.
4, power grounding point. The power supply can be grounded at a point (usually the neutral point) for grounding? .
Expanded information:
Storage of grounding wires:
1, grounding wire storage
2, after the use of processing: grounding wire should be cleaned, wiped after use, and should check the appearance of good. The person in charge of the work should register the use of grounding wire, after the completion of the work must be counted in each group of grounding wire and determine the recovery of the grounding wire and bring out the number of grounding wires, labeling the same.
3, storage and management requirements: each group of grounding wire should be numbered, and stored in a special room (cabinet) corresponding position number storage, so as to avoid the law of God mistakenly dismantled or omitted to dismantle the grounding wire caused by accidents. Annual frequency voltage preventive test, every 5 years into a group of DC resistance test.
4, end-of-life standards: grounding wire in a short-circuit current, once should be scrapped as a whole.
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