電(dian)氣(qi)(qi)設(she)(she)備(bei)(bei)的接(jie)(jie)地(di)(di)部分(fen)則是(shi)正常(chang)情(qing)況下不帶電(dian)的金(jin)屬(shu)導(dao)體，一般為金(jin)屬(shu)外殼。電(dian)氣(qi)(qi)設(she)(she)備(bei)(bei)接(jie)(jie)地(di)(di)裝置(zhi)由(you)接(jie)(jie)地(di)(di)體和(he)接(jie)(jie)地(di)(di)線組成。與土壤直接(jie)(jie)接(jie)(jie)觸的金(jin)屬(shu)體稱(cheng)為接(jie)(jie)地(di)(di)體；連(lian)接(jie)(jie)電(dian)氣(qi)(qi)設(she)(she)備(bei)(bei)與接(jie)(jie)地(di)(di)體之間(jian)的導(dao)線（或導(dao)體）稱(cheng)為接(jie)(jie)地(di)(di)線。
　　1.1安全保護(hu)接(jie)地(di)。主要包括：為防止(zhi)電力設(she)(she)施或(huo)電子電氣設(she)(she)備絕緣(yuan)損壞、危及(ji)人身安全而(er)(er)設(she)(she)置(zhi)的(de)保護(hu)接(jie)地(di)；為消除生產(chan)過程中產(chan)生的(de)靜電積累，引(yin)起觸電或(huo)爆炸(zha)而(er)(er)設(she)(she)的(de)靜電接(jie)地(di)；為防止(zhi)電磁(ci)感應而(er)(er)對設(she)(she)備的(de)金(jin)屬外殼、屏(ping)蔽(bi)罩或(huo)屏(ping)蔽(bi)線外皮所進行的(de)屏(ping)蔽(bi)接(jie)地(di)。其中保護(hu)接(jie)地(di)應用最為廣(guang)泛，它將機（外）殼接(jie)地(di)。此種接(jie)地(di)的(de)目的(de)是(shi)為了(le)安全。
　　1.2系(xi)統接(jie)(jie)地(di)。這種接(jie)(jie)地(di)給電(dian)路系(xi)統提供一個基準電(dian)位（電(dian)位），同時(shi)也可將千擾(rao)引走。此種接(jie)(jie)地(di)目的是為(wei)了抵制外部(bu)的千擾(rao)。
　　1.3防(fang)雷接(jie)(jie)地(di)。為防(fang)止雷電(dian)過電(dian)壓對(dui)人身或設備產(chan)生(sheng)危害(hai)，而設置(zhi)的(de)過電(dian)壓保護設備的(de)接(jie)(jie)地(di)，稱為防(fang)雷接(jie)(jie)地(di)，如避雷針、避雷器的(de)接(jie)(jie)地(di)。
　　1.4重(zhong)復接(jie)(jie)地。在低壓配電(dian)系(xi)統的(de)系(xi)統中(zhong)，為(wei)防(fang)止因中(zhong)性(xing)線(xian)故障而失去接(jie)(jie)地保(bao)護作用，造成(cheng)電(dian)擊(ji)危(wei)險和損壞設備，對中(zhong)性(xing)線(xian)進(jin)行重(zhong)復接(jie)(jie)地。系(xi)統中(zhong)的(de)重(zhong)復接(jie)(jie)地點(dian)為(wei)：架空(kong)線(xian)路的(de)終端(duan)及線(xian)路中(zhong)適當點(dian)；四芯(xin)電(dian)纜(lan)的(de)中(zhong)性(xing)線(xian)；電(dian)纜(lan)或架空(kong)線(xian)路在建(jian)筑物或車間的(de)進(jin)線(xian)處。
　　1.5防靜電(dian)接(jie)地(di)。為了消(xiao)除靜電(dian)對人身(shen)和設備產生危害而進行的接(jie)地(di)，如將某(mou)些液體或氣體的金屬輸送管道或車輛(liang)的接(jie)地(di)。
　　1.6屏(ping)蔽接地(di)。為防止電(dian)氣(qi)設備因受電(dian)磁(ci)千擾，而影響其工作或對其他設備造成電(dian)磁(ci)千擾的屏(ping)蔽設備的接地(di)。
　　我們往(wang)往(wang)只知(zhi)道接地(di)可(ke)(ke)防(fang)止人身遭受電(dian)擊，其實(shi)接地(di)除了這一作用外，還(huan)可(ke)(ke)以防(fang)止設備(bei)和線路遭受損(sun)壞、預防(fang)火(huo)災、防(fang)止雷擊、防(fang)止靜電(dian)損(sun)害和保*電(dian)力系統的正常運行。
　　2.1防止電(dian)(dian)(dian)擊(ji)。人(ren)體阻(zu)抗和所處環境(jing)的(de)狀況有(you)(you)極大(da)的(de)關系，環境(jing)越(yue)(yue)潮(chao)濕，人(ren)體的(de)阻(zu)抗越(yue)(yue)低，也(ye)越(yue)(yue)容(rong)易遭受(shou)電(dian)(dian)(dian)擊(ji)。例如，自裝過(guo)交(jiao)流(liu)收音機(ji)的(de)人(ren)幾(ji)(ji)乎都受(shou)到過(guo)電(dian)(dian)(dian)擊(ji)，但幾(ji)(ji)乎都能擺脫電(dian)(dian)(dian)源(yuan)，因為此時人(ren)所處的(de)環境(jing)千燥，皮膚也(ye)較(jiao)千燥。接地是(shi)防止電(dian)(dian)(dian)擊(ji)的(de)種有(you)(you)效(xiao)的(de)方(fang)法(fa)。
　　電(dian)(dian)(dian)(dian)氣(qi)(qi)設(she)(she)備(bei)通過接地(di)(di)裝置(zhi)接地(di)(di)后，使電(dian)(dian)(dian)(dian)氣(qi)(qi)設(she)(she)備(bei)的(de)電(dian)(dian)(dian)(dian)位(wei)接近地(di)(di)電(dian)(dian)(dian)(dian)位(wei)。由于(yu)接地(di)(di)電(dian)(dian)(dian)(dian)阻的(de)存在，電(dian)(dian)(dian)(dian)氣(qi)(qi)設(she)(she)備(bei)對地(di)(di)電(dian)(dian)(dian)(dian)位(wei)總是存在的(de)，電(dian)(dian)(dian)(dian)氣(qi)(qi)設(she)(she)備(bei)的(de)接地(di)(di)電(dian)(dian)(dian)(dian)阻越大，發(fa)生故(gu)障時(shi)，電(dian)(dian)(dian)(dian)氣(qi)(qi)設(she)(she)備(bei)的(de)對地(di)(di)電(dian)(dian)(dian)(dian)位(wei)也(ye)(ye)越大，人觸及時(shi)的(de)危險性(xing)也(ye)(ye)越大。但是，如(ru)果(guo)不(bu)設(she)(she)置(zhi)接地(di)(di)裝置(zhi)，故(gu)障設(she)(she)備(bei)外(wai)殼的(de)電(dian)(dian)(dian)(dian)壓f就和(he)相線對地(di)(di)電(dian)(dian)(dian)(dian)壓相同，比起接地(di)(di)電(dian)(dian)(dian)(dian)壓還(huan)是高出很多的(de)，因此危險性(xing)也(ye)(ye)相應增加。
　　2.2保*電(dian)(dian)力(li)系(xi)統(tong)的正常運行。電(dian)(dian)力(li)系(xi)統(tong)的接(jie)地(di)(di)，又稱工作(zuo)接(jie)地(di)(di)，一(yi)般在變電(dian)(dian)站(zhan)或變電(dian)(dian)所對(dui)中(zhong)性(xing)點(dian)進行接(jie)地(di)(di)。工作(zuo)接(jie)地(di)(di)的接(jie)地(di)(di)電(dian)(dian)阻要(yao)求(qiu)很小，對(dui)大型的變電(dian)(dian)站(zhan)要(yao)求(qiu)有(you)一(yi)個接(jie)地(di)(di)網，保*接(jie)地(di)(di)電(dian)(dian)阻小而且(qie)可靠。工作(zuo)接(jie)地(di)(di)的目的是使電(dian)(dian)網的中(zhong)性(xing)點(dian)與地(di)(di)之間(jian)的電(dian)(dian)位接(jie)近(jin)于零。
　　2.3防止(zhi)雷(lei)(lei)擊和(he)靜電的危害。雷(lei)(lei)電發生時，除了(le)直接雷(lei)(lei)外，還(huan)會生產感應雷(lei)(lei)，感應雷(lei)(lei)又分為靜電感應雷(lei)(lei)和(he)電磁(ci)感應雷(lei)(lei)。所有防雷(lei)(lei)措施中最主要的方法(fa)是(shi)接地。
　　3電氣設備(bei)接(jie)地技術原則3.1為(wei)保*人身和設備(bei)安(an)全，各種電氣設備(bei)均(jun)應(ying)根據(ju)國家標準(zhun)GB14050系統接(jie)地的(de)形式及(ji)安(an)全技術要求(qiu)進(jin)行保護接(jie)地。保護接(jie)地線(xian)除用(yong)以實現規定的(de)工作接(jie)地或(huo)保護接(jie)地的(de)要求(qiu)外，不應(ying)作其他(ta)用(yong)途。
　　3.2不同用(yong)途和不同電(dian)壓(ya)的電(dian)氣設備，除(chu)有特殊要(yao)求外(wai)，一般(ban)應(ying)使用(yong)一個總的接(jie)(jie)地體，按等(deng)電(dian)位(wei)連(lian)接(jie)(jie)要(yao)求，應(ying)將建筑物金(jin)屬(shu)(shu)構件、金(jin)屬(shu)(shu)管道（輸送易燃易爆物的金(jin)屬(shu)(shu)管道除(chu)外(wai)）與總接(jie)(jie)地體相連(lian)接(jie)(jie)。
　　3.3人(ren)工總(zong)接(jie)地(di)體(ti)(ti)不(bu)宜(yi)設在(zai)建筑物內，總(zong)接(jie)地(di)體(ti)(ti)的接(jie)地(di)電阻(zu)應滿足(zu)各種接(jie)地(di)中最小的接(jie)地(di)電阻(zu)要(yao)求。
　　3.4有(you)特殊(shu)要求(qiu)的(de)接地，如弱(ruo)電(dian)系統、計算機系統及中(zhong)(zhong)壓系統，為中(zhong)(zhong)性(xing)點(dian)直接接地或經(jing)小電(dian)阻接地時，應按有(you)關專項規定執行。
　　4電(dian)(dian)(dian)(dian)(dian)氣設備(bei)接(jie)地(di)方法安全(quan)保(bao)(bao)(bao)護接(jie)地(di)4.1.1保(bao)(bao)(bao)護接(jie)零。三相(xiang)(xiang)四(si)線(xian)制供電(dian)(dian)(dian)(dian)(dian)系(xi)統中(zhong)(zhong)的(de)(de)(de)(de)中(zhong)(zhong)性(xing)線(xian)，即(ji)為保(bao)(bao)(bao)護接(jie)零線(xian)，它是(shi)電(dian)(dian)(dian)(dian)(dian)路(lu)環(huan)路(lu)的(de)(de)(de)(de)重要組成(cheng)(cheng)部分。在中(zhong)(zhong)性(xing)點直接(jie)接(jie)地(di)的(de)(de)(de)(de)三相(xiang)(xiang)四(si)線(xian)制電(dian)(dian)(dian)(dian)(dian)網中(zhong)(zhong)，電(dian)(dian)(dian)(dian)(dian)子電(dian)(dian)(dian)(dian)(dian)氣設備(bei)應保(bao)(bao)(bao)護接(jie)零。將電(dian)(dian)(dian)(dian)(dian)子電(dian)(dian)(dian)(dian)(dian)氣設備(bei)正(zheng)常運行(xing)時(shi)不(bu)帶電(dian)(dian)(dian)(dian)(dian)的(de)(de)(de)(de)金屬外殼(ke)與電(dian)(dian)(dian)(dian)(dian)網的(de)(de)(de)(de)零線(xian)連(lian)接(jie)起來，當相(xiang)(xiang)發生漏電(dian)(dian)(dian)(dian)(dian)或碰殼(ke)時(shi)，由于金屬外殼(ke)與零線(xian)相(xiang)(xiang)連(lian)，形成(cheng)(cheng)單相(xiang)(xiang)短路(lu)，電(dian)(dian)(dian)(dian)(dian)流很大(da)，使電(dian)(dian)(dian)(dian)(dian)路(lu)保(bao)(bao)(bao)護裝置迅速動作(zuo)，切斷(duan)電(dian)(dian)(dian)(dian)(dian)源(yuan)。在采用(yong)(yong)接(jie)零保(bao)(bao)(bao)護時(shi)，電(dian)(dian)(dian)(dian)(dian)源(yuan)中(zhong)(zhong)線(xian)不(bu)允許斷(duan)開，如果中(zhong)(zhong)線(xian)斷(duan)開，將會失去保(bao)(bao)(bao)護作(zuo)用(yong)(yong)。通(tong)常系(xi)統中(zhong)(zhong)采用(yong)(yong)零線(xian)重復接(jie)地(di)的(de)(de)(de)(de)方法實現保(bao)(bao)(bao)護作(zuo)用(yong)(yong)。
　　4.1.2保護(hu)(hu)(hu)接(jie)(jie)地(di)。為防止觸電事故而(er)裝設的接(jie)(jie)地(di)，稱之為保護(hu)(hu)(hu)接(jie)(jie)地(di)。保護(hu)(hu)(hu)接(jie)(jie)地(di)僅適(shi)用于(yu)中性(xing)點(dian)不接(jie)(jie)地(di)的電網(wang)。凡(fan)在這個電網(wang)中的電氣設備的金屬(shu)外殼(ke)、支架及(ji)相(xiang)連的金屬(shu)部分均應(ying)接(jie)(jie)地(di)。中性(xing)點(dian)接(jie)(jie)地(di)的電路系統不宜采用保護(hu)(hu)(hu)接(jie)(jie)地(di)。
　　系(xi)統接地線既是各電(dian)(dian)(dian)路中的(de)靜態(tai)、動態(tai)電(dian)(dian)(dian)流通道，又是各級電(dian)(dian)(dian)路通過共同的(de)接地阻抗而相互耦合的(de)途徑，從而形成電(dian)(dian)(dian)路間相互千擾的(de)薄弱(ruo)環(huan)節。所以，電(dian)(dian)(dian)子電(dian)(dian)(dian)氣(qi)儀器設備中的(de)一切(qie)抗千擾技術，都(dou)和(he)接地有關。電(dian)(dian)(dian)子電(dian)(dian)(dian)氣(qi)儀器設備中的(de)系(xi)統接地是否要接大地和(he)如何接大地，與系(xi)統的(de)工作穩(wen)定性有著密切(qie)的(de)關系(xi)，通常有4種方式。
　　4.2.1浮地(di)方(fang)式(shi)。浮地(di)就(jiu)是(shi)不接(jie)大(da)地(di)，是(shi)一種(zhong)懸(xuan)浮的(de)(de)方(fang)式(shi)，其(qi)目的(de)(de)是(shi)將(jiang)電(dian)(dian)(dian)路或(huo)設(she)備(bei)(bei)與(yu)公共(gong)地(di)或(huo)可(ke)能引起環(huan)流的(de)(de)公共(gong)導線(xian)隔離開來，從而抑(yi)制來自接(jie)地(di)線(xian)的(de)(de)千擾。這種(zhong)接(jie)地(di)方(fang)式(shi)的(de)(de)缺(que)點是(shi)設(she)備(bei)(bei)不與(yu)大(da)地(di)直(zhi)接(jie)相(xiang)連，容易出現(xian)靜電(dian)(dian)(dian)積(ji)累現(xian)象，這樣積(ji)累起來的(de)(de)電(dian)(dian)(dian)荷達(da)到一定程度(du)后，在設(she)備(bei)(bei)和大(da)地(di)之(zhi)間會產生(sheng)具有(you)強(qiang)大(da)放電(dian)(dian)(dian)電(dian)(dian)(dian)流的(de)(de)靜電(dian)(dian)(dian)擊穿現(xian)象，這是(shi)一種(zhong)破壞(huai)性(xing)很強(qiang)的(de)(de)千擾源(yuan)。
　　4.2.2單(dan)點(dian)接(jie)(jie)地(di)方式。由于(yu)2點(dian)接(jie)(jie)地(di)易形成接(jie)(jie)地(di)環路(lu)(lu)，所以(yi)點(dian)接(jie)(jie)地(di)的功能是消(xiao)除和(he)防止(zhi)形成接(jie)(jie)地(di)環路(lu)(lu)。單(dan)點(dian)接(jie)(jie)地(di)有串(chuan)聯和(he)并聯2種方式。單(dan)點(dian)接(jie)(jie)地(di)是為許多接(jie)(jie)在一起的電路(lu)(lu)系統提供(gong)共同點(dian)。
　　電(dian)(dian)(dian)流(liu)流(liu)過接地(di)導(dao)線時(shi)，導(dao)線中或多或少有(you)阻(zu)抗(kang)(kang)。串聯接地(di)電(dian)(dian)(dian)路(lu)電(dian)(dian)(dian)流(liu)11，2IN都經過阻(zu)抗(kang)(kang)Z1，Z1是電(dian)(dian)(dian)路(lu)1，2N共有(you)的共同阻(zu)抗(kang)(kang)，因(yin)此，電(dian)(dian)(dian)路(lu)1，2N的電(dian)(dian)(dian)位受11，2IN共同影響，它們之間互(hu)(hu)相(xiang)牽制(zhi)。而并聯接地(di)方式沒有(you)公共阻(zu)抗(kang)(kang)，電(dian)(dian)(dian)路(lu)1，2N互(hu)(hu)不千擾(rao)，所以并聯接地(di)最為(wei)簡單實用。
　　4.2.3多點接(jie)地方式。對于高(gao)頻電(dian)路（信(xin)號頻率為10MHz以上，由于各元器(qi)件的(de)(de)(de)引線(xian)(xian)和(he)電(dian)路本身(shen)布局的(de)(de)(de)電(dian)感都(dou)將增(zeng)加接(jie)地線(xian)(xian)的(de)(de)(de)阻抗，一點接(jie)地方式已不再適用。為了降低接(jie)地線(xian)(xian)阻抗及減少地線(xian)(xian)間的(de)(de)(de)雜散(san)電(dian)感和(he)分(fen)布電(dian)容所造成的(de)(de)(de)電(dian)路間的(de)(de)(de)相互耦(ou)合(he)，應短距離把各元器(qi)件接(jie)地端(duan)子接(jie)在此地面(mian)上。
　　4.2.4混合(he)接(jie)(jie)(jie)地(di)。電(dian)路(lu)系統(tong)既有(you)低(di)(di)頻(pin)電(dian)路(lu)，又(you)有(you)高頻(pin)電(dian)路(lu)或數字電(dian)路(lu)時(shi)，在(zai)系統(tong)中應采用(yong)混合(he)接(jie)(jie)(jie)地(di)方(fang)(fang)式。電(dian)路(lu)系統(tong)中的低(di)(di)頻(pin)部(bu)分采用(yong)單點(dian)(dian)接(jie)(jie)(jie)地(di)，而高頻(pin)部(bu)分則(ze)需要(yao)多點(dian)(dian)接(jie)(jie)(jie)地(di)，這樣的接(jie)(jie)(jie)地(di)方(fang)(fang)式既包含了單點(dian)(dian)接(jie)(jie)(jie)地(di)的特性(xing)，又(you)包含了多點(dian)(dian)接(jie)(jie)(jie)地(di)的特性(xing)，從(cong)而達到較佳抑制千擾的目的。