【正文】 kinds of wiring while carrying. These electronic equipment and wiring system generally belong to and able to bear the grade of pressing low , defend and interfere expecting much , is most afraid of the part struck by lightning. No matter attack directly, bunch hit, is it can make electronic equipment the damage in various degree or interfere seriously to strike back. It designs to be must tight , reliable to intelligent dyke thunder earth of building. Intelligent all function earth of building, must in order to avoid thunder based on the system earth, set up tightly , intact dyke thunder structure.　The intelligent building is mostly first class load, should design according to the protective measure of first class Fang thunder building , connect person who flash adopt needle is it is it connect person who flash to make up to take , is it is it adopt 25* 4 (mm ) zincplated flatrolled steel make up net of ≤ 10* 10 (m ) in roof to take to take shelter from the thunder, this net and metal ponent of the roofing are joined electrically, 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 .s earth: For is it channel earth into rapidly to flow thunder and lightning, taking preventing the thunder from hurting as purpose earth is it defend thunder39。 Will expand the range which will shock by electricity the accident。 Some clearcut to is it answer together to mix N line , PE line , direct current earth connection. The above methods do not accord with earth requirement , and wrong. Have analysed , in the intelligent building, there is more singlephase power consuming equipment in in the front, singlephase load is relatively great in specific gravity, threephase load is usually uneven, so there is random electric current in the neutral line N. In addition, because adopt the fluorescent lamp to light in a large amount, the waves in harmony three times produced by it are superposed on the N line, have strengthened the electric current amount on the N line, if receive N line on the equipment outer cover , will cause shocking by electricity or fire accident 。 Is it together , join N line and PE line really stiff to get on to connect among the system in TNS。t have any electric connection. In this system, the neutral line N regular meeting protects the earth connection PE source without electricity with electricity. Equipment outer cover and metal ponent that PE line connects are in system normal running, will not be with electricity all the time. So TNS earth system has obviously improved the securities of people and thing . At the same time so long as we adopt the earth lead wire, draw from earth body some each, choose correct earth resistance value make electronic equipment obtain one electric potential datum point ,etc. measure together, then TNCS system can be regarded as a kind of earth system of the intelligent building. system　TNS is a earth system that threephase Line four added PE line. Building usually is it enter line adopt this system when turning distribution into independently to have. The characteristic of TNS system is, neutral line N and protecting earth connection PE except in the voltage transformer is grounded neutrally more together a bit, Line two no longer has electric connection of any. Neutral line N belong to electrification, but PE with electricity line. It39。Summary : This text pass to several power supply earth systematic generalization introduction, is it suit as intellectual power supply earth system of building to screen, and has done paratively exhaustive explanation and analysis to all kinds of earth measures should be takenned by it, electric protection that should adopt to the intellectual building and connecting the proper suggestion of local law proposition.Keyword: Load is balanced Electric potential form some earth , TNS of datum point , defend static earth unify the earth body. Support distribution in the design , earth is it occupy important status to design systematically in building, because it concerns the dependability of the electric power system , the security . No matter how many buildings, include earth design systematically always in supplying power design. And, different with requirements of the building, functions of all kinds of equipment are different, earth systems are corresponding and different t