如果(guo)出(chu)現單相接地(di)故(gu)障，對(dui)地(di)漏(lou)電流(liu)只能(neng)經(jing)過系(xi)(xi)統(tong)泄(xie)露電容對(dui)系(xi)(xi)統(tong)相線構(gou)成(cheng)回(hui)(hui)路(lu)，而系(xi)(xi)統(tong)泄(xie)露電容引起(qi)的(de)(de)(de)容抗總是(shi)(shi)遠遠大于TN系(xi)(xi)統(tong)中的(de)(de)(de)接地(di)電阻(zu)，因(yin)(yin)此IT系(xi)(xi)統(tong)中的(de)(de)(de)漏(lou)電流(liu)非(fei)常的(de)(de)(de)小，斷路(lu)器(qi)不會因(yin)(yin)接地(di)電流(liu)的(de)(de)(de)存在(zai)(zai)(zai)而引起(qi)過電流(liu)動(dong)作(zuo)，從而保(bao)證系(xi)(xi)統(tong)帶故(gu)障運行。在(zai)(zai)(zai)隔(ge)離變(bian)(bian)壓器(qi)系(xi)(xi)統(tong)中，提高回(hui)(hui)路(lu)的(de)(de)(de)絕緣(yuan)阻(zu)抗降低回(hui)(hui)路(lu)對(dui)地(di)電容，是(shi)(shi)提高系(xi)(xi)統(tong)安(an)全性與可靠性的(de)(de)(de)關鍵(jian)。因(yin)(yin)此在(zai)(zai)(zai)系(xi)(xi)統(tong)設計時要(yao)盡量縮短(duan)系(xi)(xi)統(tong)配電線路(lu)的(de)(de)(de)長(chang)度，減小系(xi)(xi)統(tong)容量，減少(shao)系(xi)(xi)統(tong)分支回(hui)(hui)路(lu)數(shu)，并做好線路(lu)的(de)(de)(de)絕緣(yuan)防護措施。醫用IT供電系(xi)(xi)統(tong)由(you)一臺隔(ge)離變(bian)(bian)壓器(qi)，一臺絕緣(yuan)電阻(zu)，變(bian)(bian)壓器(qi)溫度與電流(liu)負荷監測設備和一臺安(an)裝于手術室或(huo)臨近的(de)(de)(de)護士間的(de)(de)(de)操作(zuo)與報警終端組成(cheng)。

在(zai)隔離變壓器系統(tong)中，提高回路(lu)(lu)的(de)絕(jue)緣阻抗降低回路(lu)(lu)對地電(dian)(dian)容，是提高系統(tong)安全性與可(ke)靠(kao)性的(de)關(guan)鍵。因此在(zai)系統(tong)設計時要盡(jin)量(liang)縮短系統(tong)配電(dian)(dian)線(xian)路(lu)(lu)的(de)長(chang)度，減小系統(tong)容量(liang)，減少系統(tong)分(fen)支回路(lu)(lu)數，并做(zuo)好(hao)線(xian)路(lu)(lu)的(de)絕(jue)緣防(fang)護措施。這也就限制(zhi)了(le) IT 系統(tong)僅能用在(zai)重要的(de)局(ju)部的(de)供電(dian)(dian)場(chang)所，如化工(gong)、制(zhi)藥企業的(de)一些(xie)程序控制(zhi)生產線(xian)，醫用場(chang)所的(de)手術室、監護室等場(chang)所。

IT系(xi)(xi)統(tong)(tong)作(zuo)用(yong)(yong)：降(jiang)低出點(dian)(dian)電(dian)(dian)(dian)(dian)壓(ya)(ya)和電(dian)(dian)(dian)(dian)網對地(di)漏(lou)(lou)電(dian)(dian)(dian)(dian)流（有效控(kong)制(zhi)對心臟(zang)的(de)直接(jie)漏(lou)(lou)電(dian)(dian)(dian)(dian)），故人身觸電(dian)(dian)(dian)(dian)危險被降(jiang)到低程度。可以(yi)(yi)防(fang)止接(jie)地(di)系(xi)(xi)統(tong)(tong)內(nei)漏(lou)(lou)電(dian)(dian)(dian)(dian)流竄入某些(xie)與患者連(lian)接(jie)的(de)醫(yi)用(yong)(yong)電(dian)(dian)(dian)(dian)器(qi)(qi)設(she)備(bei)的(de)對地(di)回路，從(cong)而避免漏(lou)(lou)電(dian)(dian)(dian)(dian)對患者安全所構成的(de)威脅。該系(xi)(xi)統(tong)(tong)還可以(yi)(yi)避免漏(lou)(lou)電(dian)(dian)(dian)(dian)導(dao)致(zhi)(zhi)系(xi)(xi)統(tong)(tong)短(duan)路器(qi)(qi)或熔斷器(qi)(qi)動(dong)作(zuo)，it服務(wu)管(guan)理(li)系(xi)(xi)統(tong)(tong)，保(bao)證用(yong)(yong)電(dian)(dian)(dian)(dian)的(de)持(chi)(chi)續性(xing)(xing)和可靠性(xing)(xing)。在一些(xie)重要的(de)場(chang)所，由于隔(ge)(ge)離變(bian)壓(ya)(ya)器(qi)(qi)持(chi)(chi)續不(bu)斷地(di)工作(zuo)，可能溫(wen)度過(guo)高(gao)而導(dao)致(zhi)(zhi)隔(ge)(ge)離變(bian)壓(ya)(ya)器(qi)(qi)工作(zuo)異常。因此絕緣(yuan)監測器(qi)(qi)還需要實(shi)時檢測變(bian)壓(ya)(ya)器(qi)(qi)的(de)溫(wen)度，當其溫(wen)度過(guo)高(gao)時，應(ying)有相(xiang)應(ying)的(de)超溫(wen)報警信號，以(yi)(yi)提醒相(xiang)關人員及時處理(li)。 醫(yi)用(yong)(yong)IT系(xi)(xi)統(tong)(tong)（俗(su)稱(cheng)醫(yi)用(yong)(yong)隔(ge)(ge)離電(dian)(dian)(dian)(dian)源系(xi)(xi)統(tong)(tong)），又叫中(zhong)(zhong)(zhong)性(xing)(xing)點(dian)(dian)不(bu)接(jie)地(di)配電(dian)(dian)(dian)(dian)系(xi)(xi)統(tong)(tong)。在IT系(xi)(xi)統(tong)(tong)中(zhong)(zhong)(zhong)，系(xi)(xi)統(tong)(tong)中(zhong)(zhong)(zhong)性(xing)(xing)點(dian)(dian)對地(di)完全隔(ge)(ge)離，系(xi)(xi)統(tong)(tong)負(fu)載中(zhong)(zhong)(zhong)的(de)外殼(ke)經接(jie)地(di)保(bao)護線接(jie)地(di)。