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MPM-A1652F-MJ72AA

尊敬的客戶您好！相遇，是一個多么動人的名詞。于這茫茫人海中，于這網(wǎng)海茫茫中，每天有多少的相遇擦肩而過，每天又有多少的匆匆擦肩而過。而緣分，讓你我相遇。期待您的來電！珍惜這得來不易的緣。

MPM-A2152F-SJ72AA

Signal ground: the ground of an b signal element-sensor; the ground of an AC power supply; the ground of an n wire, usually where the main noise is generated; the ground of an enclosure or wire Mesh, usually to prevent electrostatic or magnetic induction, it is connected to the earth by a special copper wire. Protective Ground: generally ground the outer shell of the machine or the independent device inside the machine to protect the personal safety and protect the equipment from electric leakage. The above several kinds of situations have not solved well can choose the suitable isolator product to solve the common ground interference problem. 4.2 earthing of DCS: There are two types of "earthing" in computer control systems. One is the enclosure and shielding of the equipment, which is usually connected to the earth. The purpose of earthing is to avoid the electric charge of the casing which affects the safety of personnel and equipment, and to keep the electric potential between the casing and the shielding layer and the earth so as to shield the external electromagnetic interference. The other is the reference status of the power source or signal. In microcomputer control system, there are analog signal, digital signal, and power (DC) voltage ground terminal. The ground of these signals is ultimaby the ground of the DC power supply. In order to prevent the interference caused by the common impedance, "bus bar separate wiring" is adopted, that is, analog and digital are separated in the circuit, bus bar separate wiring is adopted, and finally two ground are connected together at one point. The Shield layer of the signal adopts the principle of single-point grounding, which can prevent the potential difference (UCM) between different grounding points from bing a current loop through the shield layer and causing interference. Different types of DCS system have different requirements for grounding, but in the final analysis it is to meet the requirements of "a little grounding" . Finally, only one point of the whole grounding system is connected to the grounding grid and meets the requirements of the grounding resistance. The grounding requirement of DCS system should be definite, complete and complete, and can not be changed to meet the different requirements of users. In the power plant environment, DCS is required to have strong anti-interference ability, and the users expect the grounding mode and grounding resistance to be relaxed. But only strictly according to the requirements of manufacturers to implement system grounding, to ensure the system stable operation, but also to facilitate the early exclusion of some fault grounding factors. Following to XX Power Plant Control System (Symphony) ground as an example for analysis: This project does not set a separate DCS ground system, Symphony system of the process control cabinet through the grounding cable in series, the final point is connected to the electrical grounding grid by a single point at the power supply cabinet, and the grounding point within a radius of 5 meters is the one without large current and voltage starting and stopping equipment. The power supply cables from the power supply to the distribution panel and from the distribution panel to the module cabinet shall use 3-core cables as the fire wire, the middle wire and the ground wire respectively. The Middle Wire and the ground wire shall be shorted at the power outlet, connect this short contact to the nearest reliable building grounding system using a flat grounded copper cable (see note 2) , otherwise the center and ground wires should not be shorted anywhere else. When using two-way power supply, it is best to ground the two power supply at the same point.

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MPM-A1652F-MJ72AA

MPM-A1652F-MJ72AA