因(yin)此(ci)對電(dian)(dian)(dian)(dian)(dian)(dian)(dian)氣安(an)全設計也提出了特殊的(de)(de)(de)要(yao)求。手術(shu)室、ICU、CCU病房等這些對電(dian)(dian)(dian)(dian)(dian)(dian)(dian)力可靠(kao)性(xing)要(yao)求很高(gao)的(de)(de)(de)場(chang)所，不(bu)管(guan)出現任何情況，都應保證電(dian)(dian)(dian)(dian)(dian)(dian)(dian)力供應的(de)(de)(de)連續性(xing)和預防微電(dian)(dian)(dian)(dian)(dian)(dian)(dian)，否則，將導致(zhi)因(yin)維持生命的(de)(de)(de)設備斷(duan)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)或(huo)漏電(dian)(dian)(dian)(dian)(dian)(dian)(dian)而對患者造成生命危(wei)險(xian)。一般供電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)網是以大地作(zuo)為參考電(dian)(dian)(dian)(dian)(dian)(dian)(dian)位，相(xiang)線中(zhong)的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)可以通過任何未絕緣的(de)(de)(de)通道(dao)，對地構成回路(lu)(lu)，這是的(de)(de)(de)根(gen)本原(yuan)因(yin)。隔(ge)離(li)(li)供電(dian)(dian)(dian)(dian)(dian)(dian)(dian)是采(cai)用(yong)隔(ge)離(li)(li)變(bian)(bian)壓(ya)器供電(dian)(dian)(dian)(dian)(dian)(dian)(dian)，it系(xi)統(tong)(tong)廠商，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)源經隔(ge)離(li)(li)變(bian)(bian)壓(ya)器隔(ge)離(li)(li)后，原(yuan)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)網中(zhong)的(de)(de)(de)地已不(bu)再是參考電(dian)(dian)(dian)(dian)(dian)(dian)(dian)位。該(gai)系(xi)統(tong)(tong)接(jie)地故障多為金屬(shu)性(xing)短路(lu)(lu)，因(yin)故障電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)較大，使斷(duan)路(lu)(lu)器或(huo)熔斷(duan)器等過電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)保護裝置(zhi)動作(zuo)，造成房間停電(dian)(dian)(dian)(dian)(dian)(dian)(dian)。顯然TN—S系(xi)統(tong)(tong)不(bu)能滿足醫院中(zhong)一些重要(yao)場(chang)所對不(bu)間斷(duan)供電(dian)(dian)(dian)(dian)(dian)(dian)(dian)的(de)(de)(de)實(shi)用(yong)要(yao)求

醫用(yong)IT系統(tong)是指:醫用(yong)IT系統(tong)中的(de)(de)電(dian)(dian)(dian)氣設備(bei)有外(wai)露導(dao)電(dian)(dian)(dian)部(bu)分(fen)通過(guo)保護線接(jie)(jie)地(di)．而電(dian)(dian)(dian)源隔離回路中的(de)(de)設備(bei)外(wai)殼不做接(jie)(jie)地(di)。它是采(cai)用(yong)特低電(dian)(dian)(dian)壓回路輔以不接(jie)(jie)地(di)的(de)(de)等電(dian)(dian)(dian)位連接(jie)(jie)（將電(dian)(dian)(dian)源隔離區域內的(de)(de)各個電(dian)(dian)(dian)氣設備(bei)金屬外(wai)殼用(yong)絕緣導(dao)線互相(xiang)連通）來(lai)獲得好的(de)(de)安全(quan)的(de)(de)效(xiao)果。電(dian)(dian)(dian)源隔離適用(yong)于浴(yu)室、游泳(yong)池等危險大，對不間(jian)斷供(gong)電(dian)(dian)(dian)無特殊要求的(de)(de)潮(chao)濕場所。

醫用(yong)IT隔離電(dian)(dian)源(yuan)用(yong)在醫院的二類(lei)場所:各類(lei)手(shou)術(shu)室(shi)(shi)、喚醒(xing)室(shi)(shi)、監(jian)護室(shi)(shi)、心(xin)(xin)臟(zang)監(jian)護室(shi)(shi)等均(jun)屬于(yu)2類(lei)場所。在此類(lei)場合(he)醫用(yong)設備電(dian)(dian)源(yuan)中斷會(hui)引(yin)起患者生(sheng)(sheng)命(ming)危險；微(wei)弱的漏電(dian)(dian)流會(hui)產生(sheng)(sheng)”微(wei)電(dian)(dian)流“。在這(zhe)類(lei)場合(he)使(shi)用(yong)的醫用(yong)電(dian)(dian)氣設備包括：在患者體表或體內使(shi)用(yong)的實時監(jian)控儀器(qi)；用(yong)于(yu)手(shou)術(shu)的儀器(qi)設備；維持(chi)患者生(sheng)(sheng)命(ming)和軀(qu)體功(gong)能的設備；用(yong)于(yu)打(da)開心(xin)(xin)臟(zang)、大腦(nao)的設備。