為此我(wo)們必須采取(qu)一定的(de)措施，預防變壓器中性(xing)線與接地線斷線和接地電阻升(sheng)高造成的(de)危(wei)害。

  1、變壓器接(jie)地線(xian)和(he)中性(xing)線(xian)斷線(xian)及接(jie)地電(dian)阻(zu)升高的原因：

  (1)由(you)于接(jie)(jie)(jie)地(di)體埋設不規范(fan)，安(an)裝工(gong)藝(yi)馬虎，接(jie)(jie)(jie)地(di)體與接(jie)(jie)(jie)地(di)線接(jie)(jie)(jie)頭松動，大地(di)過(guo)于干燥等，均有(you)可能造成接(jie)(jie)(jie)地(di)電阻的(de)(de)升高。 (2)由(you)于變壓器設計安(an)裝時(shi)，對接(jie)(jie)(jie)地(di)線的(de)(de)作用及重要性認(ren)識不足(zu)，中性線截(jie)面(mian)選擇過(guo)小(xiao)，當三相負(fu)荷不平(ping)衡時(shi)，中性線電流(liu)過(guo)大而導致(zhi)燒斷。另(ling)外由(you)于外力的(de)(de)破壞或接(jie)(jie)(jie)地(di)線被盜等原因都有(you)可能導致(zhi)接(jie)(jie)(jie)地(di)線或中性線斷線。

  2、升高的現象及危害(hai)

  (1)變(bian)(bian)(bian)壓(ya)(ya)(ya)(ya)(ya)器(qi)(qi)(qi)接(jie)(jie)(jie)(jie)(jie)(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)(di)(di)線(xian)(xian)(xian)(xian)(xian)接(jie)(jie)(jie)(jie)(jie)(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)(di)(di)電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)升高，同(tong)時(shi)(shi)伴有(you)相(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)線(xian)(xian)(xian)(xian)(xian)絕(jue)緣(yuan)損壞而(er)接(jie)(jie)(jie)(jie)(jie)(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)(di)(di)，例如(ru)，B相(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)接(jie)(jie)(jie)(jie)(jie)(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)(di)(di)，這時(shi)(shi)變(bian)(bian)(bian)壓(ya)(ya)(ya)(ya)(ya)器(qi)(qi)(qi)接(jie)(jie)(jie)(jie)(jie)(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)(di)(di)線(xian)(xian)(xian)(xian)(xian)中(zhong)將(jiang)(jiang)(jiang)有(you)一(yi)個(ge)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)流(liu)過(guo)，B相(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)加在大(da)(da)(da)地(di)(di)(di)(di)(di)(di)(di)(di)(di)和(he)接(jie)(jie)(jie)(jie)(jie)(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)(di)(di)電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)上(shang)，當(dang)接(jie)(jie)(jie)(jie)(jie)(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)(di)(di)電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)越(yue)大(da)(da)(da)，那么(me)接(jie)(jie)(jie)(jie)(jie)(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)(di)(di)電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)上(shang)的(de)(de)分(fen)壓(ya)(ya)(ya)(ya)(ya)就(jiu)越(yue)大(da)(da)(da)。這時(shi)(shi)，如(ru)果(guo)(guo)有(you)人誤觸(chu)變(bian)(bian)(bian)壓(ya)(ya)(ya)(ya)(ya)器(qi)(qi)(qi)接(jie)(jie)(jie)(jie)(jie)(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)(di)(di)線(xian)(xian)(xian)(xian)(xian)或中(zhong)性線(xian)(xian)(xian)(xian)(xian)以及(ji)變(bian)(bian)(bian)壓(ya)(ya)(ya)(ya)(ya)器(qi)(qi)(qi)外殼(ke)(ke)，人體將(jiang)(jiang)(jiang)和(he)接(jie)(jie)(jie)(jie)(jie)(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)(di)(di)電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)形成(cheng)并聯，如(ru)果(guo)(guo)接(jie)(jie)(jie)(jie)(jie)(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)(di)(di)電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)足夠大(da)(da)(da)，那么(me)加在人體上(shang)的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)就(jiu)會很高，導致人觸(chu)電(dian)(dian)(dian)(dian)(dian)(dian)。如(ru)果(guo)(guo)人體誤觸(chu)A相(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)或C相(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)，加在人體上(shang)的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)將(jiang)(jiang)(jiang)是(shi)線(xian)(xian)(xian)(xian)(xian)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)380V，那么(me)對(dui)人身安全將(jiang)(jiang)(jiang)造成(cheng)更(geng)大(da)(da)(da)的(de)(de)威脅。另(ling)外，由(you)于有(you)的(de)(de)用(yong)(yong)戶將(jiang)(jiang)(jiang)變(bian)(bian)(bian)壓(ya)(ya)(ya)(ya)(ya)器(qi)(qi)(qi)中(zhong)性線(xian)(xian)(xian)(xian)(xian)與用(yong)(yong)電(dian)(dian)(dian)(dian)(dian)(dian)設(she)(she)備外殼(ke)(ke)相(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)連，作保護接(jie)(jie)(jie)(jie)(jie)(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)(di)(di)用(yong)(yong)，而(er)設(she)(she)備又(you)不(bu)(bu)對(dui)地(di)(di)(di)(di)(di)(di)(di)(di)(di)絕(jue)緣(yuan)。當(dang)B相(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)接(jie)(jie)(jie)(jie)(jie)(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)(di)(di)，大(da)(da)(da)地(di)(di)(di)(di)(di)(di)(di)(di)(di)就(jiu)和(he)B相(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)等電(dian)(dian)(dian)(dian)(dian)(dian)位，相(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)就(jiu)加于大(da)(da)(da)地(di)(di)(di)(di)(di)(di)(di)(di)(di)和(he)中(zhong)性線(xian)(xian)(xian)(xian)(xian)之(zhi)間，這時(shi)(shi)用(yong)(yong)電(dian)(dian)(dian)(dian)(dian)(dian)設(she)(she)備如(ru)取用(yong)(yong)A相(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)或C相(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)源，外殼(ke)(ke)對(dui)地(di)(di)(di)(di)(di)(di)(di)(di)(di)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)將(jiang)(jiang)(jiang)升高到(dao)220V，設(she)(she)備相(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)對(dui)地(di)(di)(di)(di)(di)(di)(di)(di)(di)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)將(jiang)(jiang)(jiang)為380V。這時(shi)(shi)人如(ru)果(guo)(guo)接(jie)(jie)(jie)(jie)(jie)(jie)(jie)觸(chu)用(yong)(yong)電(dian)(dian)(dian)(dian)(dian)(dian)設(she)(she)備外殼(ke)(ke)，同(tong)樣(yang)(yang)會引起觸(chu)電(dian)(dian)(dian)(dian)(dian)(dian)。另(ling)外，B相(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)接(jie)(jie)(jie)(jie)(jie)(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)(di)(di)時(shi)(shi)，將(jiang)(jiang)(jiang)有(you)一(yi)個(ge)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)從大(da)(da)(da)地(di)(di)(di)(di)(di)(di)(di)(di)(di)流(liu)入機殼(ke)(ke)回到(dao)中(zhong)性線(xian)(xian)(xian)(xian)(xian)，對(dui)于有(you)的(de)(de)要求較高的(de)(de)用(yong)(yong)電(dian)(dian)(dian)(dian)(dian)(dian)設(she)(she)備將(jiang)(jiang)(jiang)無法運行(xing)。  (2)接(jie)(jie)(jie)(jie)(jie)(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)(di)(di)線(xian)(xian)(xian)(xian)(xian)斷(duan)線(xian)(xian)(xian)(xian)(xian)，變(bian)(bian)(bian)壓(ya)(ya)(ya)(ya)(ya)器(qi)(qi)(qi)附近(jin)接(jie)(jie)(jie)(jie)(jie)(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)(di)(di)線(xian)(xian)(xian)(xian)(xian)斷(duan)線(xian)(xian)(xian)(xian)(xian)，就(jiu)猶如(ru)接(jie)(jie)(jie)(jie)(jie)(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)(di)(di)電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)升高到(dao)無窮大(da)(da)(da)，這時(shi)(shi)的(de)(de)大(da)(da)(da)地(di)(di)(di)(di)(di)(di)(di)(di)(di)電(dian)(dian)(dian)(dian)(dian)(dian)位就(jiu)是(shi)接(jie)(jie)(jie)(jie)(jie)(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)(di)(di)相(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)位，一(yi)切現象(xiang)就(jiu)同(tong)接(jie)(jie)(jie)(jie)(jie)(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)(di)(di)電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)升高時(shi)(shi)一(yi)樣(yang)(yang)，只是(shi)危害更(geng)大(da)(da)(da)，這里(li)不(bu)(bu)再(zai)重(zhong)述。  (3)當(dang)三(san)相(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)四線(xian)(xian)(xian)(xian)(xian)供電(dian)(dian)(dian)(dian)(dian)(dian)變(bian)(bian)(bian)壓(ya)(ya)(ya)(ya)(ya)器(qi)(qi)(qi)中(zhong)性線(xian)(xian)(xian)(xian)(xian)斷(duan)線(xian)(xian)(xian)(xian)(xian)時(shi)(shi)，此時(shi)(shi)由(you)于三(san)相(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)負載的(de)(de)不(bu)(bu)平衡，負載接(jie)(jie)(jie)(jie)(jie)(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)(di)(di)點將(jiang)(jiang)(jiang)發生偏(pian)移，接(jie)(jie)(jie)(jie)(jie)(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)(di)(di)點電(dian)(dian)(dian)(dian)(dian)(dian)位不(bu)(bu)為零(ling)，使(shi)得有(you)的(de)(de)相(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)升高，燒毀用(yong)(yong)電(dian)(dian)(dian)(dian)(dian)(dian)設(she)(she)備。當(dang)接(jie)(jie)(jie)(jie)(jie)(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)(di)(di)線(xian)(xian)(xian)(xian)(xian)斷(duan)線(xian)(xian)(xian)(xian)(xian)或接(jie)(jie)(jie)(jie)(jie)(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)(di)(di)電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)升高時(shi)(shi)，由(you)于變(bian)(bian)(bian)壓(ya)(ya)(ya)(ya)(ya)器(qi)(qi)(qi)避(bi)雷(lei)器(qi)(qi)(qi)接(jie)(jie)(jie)(jie)(jie)(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)(di)(di)線(xian)(xian)(xian)(xian)(xian)斷(duan)開或接(jie)(jie)(jie)(jie)(jie)(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)(di)(di)電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)升高。雷(lei)擊(ji)過(guo)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)時(shi)(shi)，避(bi)雷(lei)器(qi)(qi)(qi)不(bu)(bu)能正常對(dui)地(di)(di)(di)(di)(di)(di)(di)(di)(di)放電(dian)(dian)(dian)(dian)(dian)(dian)，致使(shi)避(bi)雷(lei)器(qi)(qi)(qi)或變(bian)(bian)(bian)壓(ya)(ya)(ya)(ya)(ya)器(qi)(qi)(qi)損壞。