Why is the grounding line exposed?
One end of the ground wire is connected with the ground, and the other end can be connected with the device shell, and can be connected with the shielding layer of the communication wire, and can be connected with the transformer iron core and so on.
1. The grounding of the device housing is to prevent the device power supply from leaking to the housing and the human body can cause electric shock accidents. When the equipment shell is effectively grounded, even if the power supply leaks to the shell, the ground wire will lead the current into the earth. The resistance of the human body is far greater than the resistance of the ground wire, so the person will not get an electric shock, and there is also a leakage circuit breaker. protection. The enclosure described here actually contains all accessible conductive components in the device, such as circuit breaker mounting rails, metal door locks and door handles, all doors, and all mounting boards must be effectively grounded.
However, not all equipment enclosures need to be grounded. For example, fully insulated cable branch boxes do not need to be grounded, and fully insulated distribution boxes do not need to be grounded. These devices are marked with a "back" on the front. Their enclosure is completely insulated, and even if the power cord is directly placed on the enclosure, people will not get an electric shock after touching the enclosure.
2. The communication line shield is grounded. This type of grounding is also common. For example, plc communication lines, servo motor communication lines, signal acquisition lines, etc. The voltage of the general communication line is relatively low, and electromagnetic interference will greatly affect the transmission effect. The shielding layer of the communication line can block electromagnetic interference. After the shielding layer is grounded, the induced voltage can be introduced into the earth. To ensure normal communication. At the same time, it can also prevent the signal in the communication line from affecting other devices in the outside world.
3. Transformer core grounded. When the core of the power transformer is in operation, it will have a large levitation voltage to the earth and it may cause discharge. So you have to ground it. But only a little grounding Oh. It will not be able to take more than one, and it will cause circulation.
These three types of grounding are more common. These grounding wires are all exposed. The ground wire is connected to the ground. Both are at the same potential. The earth can be exposed outside, and of course, the ground can also be exposed. In addition, the role of the ground wire is also enormous. It can not only prevent electric shock accidents, but also protect electrical equipment. Did you understand the ground line?