IT系(xi)統是區分(fen)(fen)了三類不同的接(jie)(jie)(jie)地(di)(di)(di)系(xi)統 字(zi)母表(biao)示電(dian)(dian)源(yuan)(yuan)(yuan)端(duan)與地(di)(di)(di)的關系(xi)：T表(biao)示電(dian)(dian)源(yuan)(yuan)(yuan)端(duan)有一(yi)點(dian)(dian)直(zhi)接(jie)(jie)(jie)接(jie)(jie)(jie)地(di)(di)(di)；I表(biao)示電(dian)(dian)源(yuan)(yuan)(yuan)端(duan)所有帶電(dian)(dian)部(bu)分(fen)(fen)不接(jie)(jie)(jie)地(di)(di)(di)或(huo)有一(yi)點(dian)(dian)通(tong)過阻抗接(jie)(jie)(jie)地(di)(di)(di)。第二個字(zi)母表(biao)示電(dian)(dian)氣(qi)(qi)裝(zhuang)(zhuang)置(zhi)的外露(lu)可導(dao)電(dian)(dian)部(bu)分(fen)(fen)與地(di)(di)(di)的關系(xi)：T表(biao)示電(dian)(dian)氣(qi)(qi)裝(zhuang)(zhuang)置(zhi)的外露(lu)可導(dao)電(dian)(dian)部(bu)分(fen)(fen)直(zhi)接(jie)(jie)(jie)接(jie)(jie)(jie)地(di)(di)(di)，此(ci)接(jie)(jie)(jie)地(di)(di)(di)點(dian)(dian)在電(dian)(dian)氣(qi)(qi)上獨立(li)于電(dian)(dian)源(yuan)(yuan)(yuan)端(duan)的接(jie)(jie)(jie)地(di)(di)(di)點(dian)(dian)；表(biao)示電(dian)(dian)氣(qi)(qi)裝(zhuang)(zhuang)置(zhi)的外露(lu)可導(dao)電(dian)(dian)部(bu)分(fen)(fen)與電(dian)(dian)源(yuan)(yuan)(yuan)端(duan)接(jie)(jie)(jie)地(di)(di)(di)有直(zhi)接(jie)(jie)(jie)電(dian)(dian)氣(qi)(qi)連(lian)接(jie)(jie)(jie)。IT系(xi)統與大地(di)(di)(di)間不直(zhi)接(jie)(jie)(jie)連(lian)接(jie)(jie)(jie)，電(dian)(dian)氣(qi)(qi)裝(zhuang)(zhuang)置(zhi)的外露(lu)可導(dao)電(dian)(dian)部(bu)分(fen)(fen)通(tong)過保護接(jie)(jie)(jie)地(di)(di)(di)線與接(jie)(jie)(jie)地(di)(di)(di)極連(lian)接(jie)(jie)(jie)。

醫用(yong)IT供電(dian)(dian)系統(tong)由一(yi)臺隔(ge)離變壓器(qi)，一(yi)臺絕(jue)(jue)(jue)緣電(dian)(dian)阻，變壓器(qi)溫度與(yu)電(dian)(dian)流負荷(he)監(jian)測設(she)備和一(yi)臺安裝于手術室或(huo)臨近的(de)(de)護士間(jian)的(de)(de)操(cao)作與(yu)報警(jing)終端(duan)組成。持(chi)續絕(jue)(jue)(jue)緣監(jian)測(IEC60364-7-710:2002-11. section 413.1.5)保(bao)證醫用(yong)設(she)施的(de)(de)絕(jue)(jue)(jue)緣電(dian)(dian)阻降低被及時(shi)監(jian)測并(bing)發出報警(jing)信(xin)號，但(決定性因(yin)素)醫用(yong)設(she)施絕(jue)(jue)(jue)緣故障不會因(yin)絕(jue)(jue)(jue)緣電(dian)(dian)阻降低導致供電(dian)(dian)中斷(duan)，因(yin)此也(ye)保(bao)證了醫用(yong)設(she)備的(de)(de)安全持(chi)續運行。

隔離(li)變(bian)(bian)(bian)壓(ya)(ya)(ya)器的(de)作(zuo)用(yong)無外乎有(you)：治理非線(xian)性負載的(de)電(dian)(dian)流(liu)畸變(bian)(bian)(bian)影(ying)(ying)響(xiang)到交(jiao)流(liu)電(dian)(dian)源的(de)正常工作(zuo)及對(dui)電(dian)(dian)網(wang)產生的(de)污染，it系統絕(jue)緣(yuan)檢(jian)測(ce)，起到凈(jing)化電(dian)(dian)網(wang)及去(qu)除(chu)諧(xie)波(bo)的(de)作(zuo)用(yong)。在隔離(li)變(bian)(bian)(bian)壓(ya)(ya)(ya)器輸入端采樣(yang)，使得非線(xian)性負載電(dian)(dian)流(liu)的(de)畸變(bian)(bian)(bian)不(bu)影(ying)(ying)響(xiang)取(qu)樣(yang)的(de)準確性，從而(er)得到能反(fan)應實際情(qing)況的(de)控制信號(hao)。若(ruo)負載分(fen)布不(bu)平(ping)衡，也不(bu)會影(ying)(ying)響(xiang)穩壓(ya)(ya)(ya)電(dian)(dian)源的(de)正常工作(zuo)狀(zhuang)態。需要說(shuo)明的(de)是因為電(dian)(dian)氣設(she)備的(de)諧(xie)波(bo)干擾(rao)(rao)原因很多很復雜，隔離(li)變(bian)(bian)(bian)壓(ya)(ya)(ya)器不(bu)是的(de)，它只(zhi)能去(qu)除(chu)三次(ci)(ci)諧(xie)波(bo)干擾(rao)(rao)功能即可以去(qu)除(chu)奇(qi)數次(ci)(ci)諧(xie)波(bo)干擾(rao)(rao)，對(dui)于別的(de)干擾(rao)(rao)也是沒有(you)什么(me)作(zuo)用(yong)的(de)。而(er)一(yi)般(ban)的(de)普通變(bian)(bian)(bian)壓(ya)(ya)(ya)器（自(zi)耦(ou)）就起到改變(bian)(bian)(bian)初、次(ci)(ci)級電(dian)(dian)壓(ya)(ya)(ya)的(de)作(zuo)用(yong)（還可以在次(ci)(ci)級抽頭分(fen)出幾個電(dian)(dian)壓(ya)(ya)(ya)等級）。