What is the role of the grounding wire

The role of the grounding wire is to electrical equipment or electrical cabinet box and other electrically powered equipment metal shell conductive part, and the earth connected to form an equipotential body. So that even if the shell of the electrical equipment due to accidental leakage, but also because the current through the grounding wire to the earth, and the earth potential connected. Ground wire resistance is very small, when the current from the box shell through the power line to the earth, the line voltage drop is very small, the box shell and the earth between the voltage is very low, negligible, so the human body in contact with the box shell, even if there is a voltage added to the human body, because the voltage is very low, through the human body current to be far smaller than the human body electrocution of the current, the human body will not be electrocuted.

All electrical appliances have a zero wire and a fire wire, thus constituting a pathway, so that the electrical appliances have a current through, function.

The ground wire, also known as lightning conductor, is used to introduce the current into the earth wire; electrical equipment leakage or high voltage, the current through the ground wire into the earth. Ground wire can not be connected to normal operation, is a setup for the safety of the user exists.

Ground can be divided into power supply ground, circuit ground. According to the wire color marking circuit, generally should be phase wire - A phase yellow, B phase green, C phase red. Zero - light blue, ground is yellow and green, if the three-hole socket, the left is zero, the center (above) is ground, the right is fire.

Electronic power equipment in the common grounding methods are: safety grounding: safety grounding that is the shell of high-voltage equipment connected to the earth; lightning grounding: generally set up in the high places of lightning rods connected to the earth in order to prevent lightning strikes endanger the safety of the equipment and personnel; work grounding: work grounding is the normal operation of the circuit is to provide a reference potential. This reference potential is generally set to zero. Unreasonable work grounding but will increase the interference of the circuit; signal: signal ground is a variety of physical quantities signal source zero potential of the public **** reference ground. Signals are generally weak, vulnerable to interference, unreasonable grounding will cause circuit interference; analog ground: analog ground is the analog circuit zero potential of the public **** reference ground. Analog circuit has a small signal amplifier circuit, multi-stage amplification, rectifier circuits, voltage regulator circuits, etc., inappropriate grounding will cause interference, affecting the normal operation of the circuit; digital ground

Digital ground is the zero potential of the digital circuit of the public **** reference ground. As digital circuits work in the pulse state, especially when the front and rear edges of the pulse is steeper or higher frequency, it will produce a large number of electromagnetic waves to interfere with the circuit. Grounding is not reasonable, the interference will be exacerbated; power ground: power ground is the power supply zero potential of the public **** reference ground; power ground: power ground is the load circuit or power drive circuit of the zero potential of the public **** reference ground.