電氣專業畢業設計外文資料及中文翻譯(編輯修改稿)

　

【文章內容簡介】 make and join with the building column cap reinforcing bar electrically, guide and roll off the production line and utilize the reinforcing bar in the column cap, enclose the reinforcing bar of roof beam , the floor reinforcing bar and defending the thunder system to join , other wall all metal ponent should with defend thunder system join , column cap reinforcing bar connect with earth body too, make up the shape of enveloping with multilayer shielding and defend the thunder system. Can is it is it damage floor equipment to strike by lightning , but also still can prevent the outside electromagnetism from interfering to prevent effectively like this. Earth resistance frequently of engineering of all kinds of dyke of thunder earth devices , should according to set thunder reaction terms at confirm generally. Defend if thunder device share one total earth at the network with job earth of electric equipment, earth resistance should accord with its minimum requirement . exchanges is grounded: Some any of power system, direct passing special equipment (such as impedance, resistance ,etc.), make metal join , call work earth with earth.　　Job earth mean voltage transformer neutral a bit or neutral line (N line ) earth mainly. N line must spend copper core insulating line. There is wiring end son of the electric potential such as being auxiliary in the distribution , wait for the wiring end son of the electric potential generally in the case cupboard. Must notice , should wire the end son and can expose 。 Can39。t with other earth system, such as direct current earth, shielding earth, defend static earth is it is it connect to mix to wait for。 Can39。t connect with PE line either.　In highpressure system , adopt neutral some person who connects place can make earth relay protection accurate movement and dispel singlephase electric arc earth overvoltage. Can prevent the skew of voltage of zero preface , keep the threephase voltage in a basic balance in some neutral earth, this is very meaningful to lowvoltage system, can be convenient to use the singlephase power. protection is grounded: Safe protection earth metal part and earth body with electricity make good metal join electric equipment. Namely power consuming equipment and some metal ponents near the equipment of building, join with PE thread, but forbid connecting PE line with N line.　In the intelligent building, require there is very much earth equipment of safe protection , there is strong electric equipment , weak electric equipment, and some conductive equipment and ponent with electricity, must take safe protection earth measure. When insulation not doing the earth electric equipment of safe protection is damaged , its outer cover is possible with electricity. If the outer cover that the human body touches this electric equipment may be wounded or caused the life danger by the electricity. Among neutral power system that ground directly a bit, earth short out electric current pass personal, the earth flows back to a bit more neutrally。 In a bit more neutrally power system not grounded directly , the earth electric current flows into the earth through the human body, and form thorough fare by electric capacity by circuit to ground, two situation these can lead to the fact the rights of the person get an electric shock.　If the insulation which is equipped with the electric equipment of the earth device is damaged while electrifying outer cover , short out in the electric current and flow through two thorough fares of earth body and human body at the same time in earth, I =IL + IP, we know: In a parallel circuit, the electric current value of passing each branch road is in inverse proportion to size of the resistance.In the type: I Electric current total value in the earth return circuitIL Electric current flowing through along the earth body IP Flow through electric current of the human body　Have type can find out earth resistance little , flow through to little electric current have human body, human resistance usually is it ground than earth resistance through electric current of human body electric current of body have several hundred less flowing through too to have several hundred heavier. When earth resistance is extremely small, the electric current that remakable body flows nearly equals zero. Namely I≈IL. In fact, because earth resistance very little, earth short out electric current flow out of date produce press and lower very lightly, so equipment outer cover voltage in earth high. People stand while going to touch the outer cover of the equipment on the earth, the voltage that the human body bears is very low, it can not be dangerous.　Is it protect earth device and reduce earth resistance of it to install additional , not only ensure the electric security of system of intelligent building, the effective measure operated effectively, it is not the essential means of equipment and personal security in the intelligent building that ensure too. current is grounded: In a block of intelligent building , include a large number of puters , munication apparatus and automation equipment of building with puter. 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