【正文】 Also can39。 Can39。 If will N line, PE line, dc grounding lines are connected together with the dangerous except happen outside, electronic equipment will be disturbed and cannot work. So intelligent building shall set up electronic equipment, the dc grounding munication grounding, safety protection grounding, and ordinary buildings also should have the lightning protection grounded. In addition, because more inside of intelligent building with requires antielectrostatic programcontrolled exchange room,Computer room, fire and fire alarm monitoring room, as well as a number of vulnerable to the electromagic interference, so precision electronic equipments in intelligent building design and construction, still should consider antistatic grounding and shielding grounding request. And then, we then analyze intelligence building should adopt the earthing measures. 一、 Exchange work grounding: somewhere in power system, directly or through special equipment (such as impedance, resistor etc) and the earth for metal connection, called work grounded. Grounding refers to the work transformer neutral point or neuter line (N line) grounded. N line must use TongXin insulation line. Existing in the distribution of terminal blocks, auxiliary equipotential potential terminals on the box normally enclosure. Must note, this terminals can39。 If in TN S system will N line together with PE line again, receiving equipment who received more dangerous, the equipment, the shell PE 畢業(yè)設計 25 online are charged。 Then or not setting electronic equipment, and the dc grounding leads to dc grounding directly to the PE online。t match the neuter line N. So it is not applicable to have large of the intelligent building singlephase equipment. In intelligent building, demanding grounding within very much, have the equipment specialized equipment, extralow equipment, and some does not normally charged of conductive equipment and ponents, all must adopt effective protection grounded. If using TN C system, will TN C system of N line also used as grounding lines。t charged. Only when onephase ground fault protection grounding sensitivity low, because cannot promptly, fault can cut off, equipment shell TT system normal operation similar to TN S system, also can obtain the safety of people and things and getting qualified benchmark grounding potential. With the capacity of the emergence of leakage protector, the system would also more and more as intelligent building grounding system. According to the current situation, because of public power grid power quality is not high, to meet the requirements, so intelligent equipment by intelligent building systems rarely TT adopt. 5. IT system IT system is threephase threewire grounding system, this system of transformer or by impedance ferroresonance, no neutral ground, only line voltage wire N (380V), no photograph by pressing (220V), the protection of ground wire PE independent grounded. The advantages of this system is when a connect, doesn39。t TN S grounding system significantly increased the safety of people and things. And as long as we take grounding lead, each from grounding body a little derivation, and choose the correct grounding resistance and make electronic equipment mon get a equipotential benchmark and other measures, so TN C S system can serve as a kind of intelligent building grounding system. 3. TN S system TN S is a threephase fourwire add PE line grounding system. Usually buildings which are equipped with independent transfering amp。 畢業(yè)設計 22 附錄 附 錄 A 外文資料 The intelligent building electrical protection and grounded Abstract: Based on several power grounding system were introduced, the generalization of the power supply for intelligent building grounding system should be taken, and the various earthing measures are detailed account of intelligent building and the analysis, should adopt the electric protection and earthing puts forward appropriate remendations. Key words: Load balance Potential Benchmark TH S Single Point Grounding Antistatic Grounding Unified Grounded The intelligent building electrical protection and earthing ways In buildings for distribution design, grounding system design occupies an important position, because it concerns the reliability of power supply system, safety. No matter what kind of building in power supply design always contain grounding system design. Moreover, as buildings requirements of different kinds of equipment, the function is different, grounding system also corresponding different. Especially in the 1990s, a large number of intelligent building after the emergence of land system design dock put forward a lot of new contents. In mon earthing types, which can be suitable for intelligent building? We might as well analyze the following grounding systems. 1. TN C system TN C system called threephase fourwire system, this system neuter line N and protect grounding PE close 2 for one, PEN appellative line. This grounding system to malfunction though docking high sensitivity, lines, but it only economic simple for a more balanced threephase load the place. Intelligent building, the proportion of singlephase load larger, difficult to achieve threephase load balance, the unbalance current PEN line with lines exist because of the fluorescent lamp, thyristor (SCR) caused equipment such as higher harmonic current, in the fault cases, will in neutral wires N superimposed on, make 畢業(yè)設計 23 the neuter line N voltage fluctuation, and current as small as unreliable, cause neutralpoint earthing potential unsta