Lightning protection and grounding system for computer room

Lightning protection and grounding system for computer room

Whether a computer system can work properly depends not only on its own software and hardware conditions, but also on the external working environment, mainly the external and internal overvoltage that affects the normal operation of the system. According to the latest statistics, electronic information equipment often stops working due to component breakdown or burnout. The important reason is that the level of transient overvoltage resistance of such equipment components is very low. If transient overvoltage is induced on the power and signal lines of the equipment, and the necessary transient overvoltage protectors are not installed on the lines, the electronic components of the equipment will be broken down. Preventing external and internal overvoltage is also a part of the normal operation investment of computer systems. If this investment is ignored, it may cause damage to the system and incur the cost of replacing and repairing equipment. In terms of the periodic investment cost over a certain period of time, it is likely to exceed the cost of installing overvoltage prevention equipment at once. Here, political, social, and other influences are temporarily disregarded, and it is possible that the impact in this area is much greater than the investment in lightning protection devices.
The concept of overvoltage: The working voltage caused by the external (mainly lightning) and internal operation of the power system exceeding the normal power supply value is called overvoltage. The duration of transient overvoltage is very short, only a few tens of microseconds,But the harm is significant. It has been observed that when the earth is struck by lightning, the average energy of negative charge discharge is30kALightning strikes that discharge positive charges to the ground appear particularly violent, usually100 kA, Gao Da200～300kA.

From a large number of computer lightning strikes, it can be analyzed that lightning electromagnetic pulses are caused by lightning induction and lightning wave invasion（LEMP）It is the main cause of damage to computers and electronic devices.

Lightning protection for power system

The lightning current invading along the power line can not only damage various electrical equipment indoors, but also cause electrical fires indoors. The power supply system of electronic devices in the computer room is transmitted from the mains power through the low-voltage distribution cabinet and then through the distribution cabinet to the computer room, and the power supply line is the main channel for lightning intrusion. Therefore, according toIEC1312The division of lightning protection zones in the lightning protection and overvoltage regulations should be divided into three zones for important systems, and each zone should be considered separately. Only implementing single-stage lightning protection may result in equipment damage due to excessive residual voltage after leakage caused by excessive lightning current or insufficient protection capability. Multi level protection of the power system can prevent the invasion of overvoltage at all levels, from direct lightning strikes to industrial surges.
The power line is the main channel for lightning intrusion, so according to the protection principles of the power system, multiple protection and layered defense should be adopted to deal with lightning protection of the power system.

Lightning protection for communication network systems

Due to the extensive use of microelectronic components such as integrated circuit chips in computer networks. The breakdown voltage of these devices is often only a few tens of volts, and the maximum allowable operating power supply is also onlymAThe ability to withstand transient overvoltage and surge voltage caused by induced lightning, electrostatic interference, electromagnetic radiation interference, etc. is greatly reduced. Therefore, it is necessary to install lightning arresters in the signal lineRS232Serial port lightning arresterRJ45Interface lightning arrester, feeder lightning arrester, etc; So as to ensure the normal operation of the computer network system. Due to the inability to count the communication cables entering and exiting the computer room at present, we did not provide specific models of signal lightning arresters in our quotation. The configuration and installation of signal lightning arresters will be carried out after all network equipment is installed.

Computer room grounding system

The grounding system is an important component of the computer room environment, which not only directly affects the communication quality of the computer room communication equipment and the normal operation of the computer room power system, but also plays a role in protecting personal safety and equipment safety.
The grounding system consists of a grounding body, grounding inlet wire, grounding coil or grounding busbar, and grounding wiring. The resistance of the grounding system is mainly determined by the soil resistance near the grounding body. If the soil resistivity is high, it is impossible to achieve a grounding resistance less than1The requirement of Ohm requires the use of manual methods to reduce the grounding resistance.