根據相關規范,對低壓電氣線路的剩余電流監控可按主干線、次干線和負載終端分3級進行。設置的基本原則是低壓配電電氣回路末端探測為主,在末端配電柜的進線或出線端設置,以便對末端配電柜至負載終端的線路和設備進行監控。
位于低壓配(pei)(pei)(pei)電系統某(mou)一路分支線到若(ruo)干個終端負載之(zhi)間的配(pei)(pei)(pei)電柜稱(cheng)為(wei)末端配(pei)(pei)(pei)電柜。例如場所區域配(pei)(pei)(pei)電柜、照明配(pei)(pei)(pei)電柜、設備(bei)專用(yong)配(pei)(pei)(pei)電柜等。
在低壓配(pei)電(dian)(dian)系(xi)統(tong)電(dian)(dian)氣回路(lu)(lu)末端正(zheng)常泄漏電(dian)(dian)流不大(da)于200mA,且上一(yi)(yi)級配(pei)電(dian)(dian)處的(de)正(zheng)常泄漏電(dian)(dian)流≤500mA,仍符合設置條件時,也可設置在其上一(yi)(yi)級配(pei)電(dian)(dian)柜處,這便可以對(dui)上下(xia)兩級之間(jian)的(de)線路(lu)(lu)和設備進行監控。
設置的(de)(de)探測器(qi)的(de)(de)報警值(zhi)必須適宜所探測電氣線路(lu),報警的(de)(de)泄(xie)(xie)漏(lou)電流(liu)值(zhi)不應小于(yu)被保護電氣線路(lu)和設備的(de)(de)正常運行時固有泄(xie)(xie)漏(lou)電流(liu)最大值(zhi)的(de)(de)2倍,并(bing)且(qie)≤1000mA。
在配電(dian)(dian)(dian)柜(ju)處設置探(tan)測(ce)器(qi)(qi)時,其柜(ju)內出線(xian)(xian)必(bi)須是TN-S系統,并且要(yao)保證(zheng)N線(xian)(xian)出線(xian)(xian)后不能重復接地。剩余(yu)電(dian)(dian)(dian)流(liu)(liu)探(tan)測(ce)器(qi)(qi)是用于380V/220V饋線(xian)(xian)回(hui)路剩余(yu)電(dian)(dian)(dian)流(liu)(liu)的(de)(de)探(tan)測(ce),是將(jiang)某一(yi)饋線(xian)(xian)回(hui)路各相(A相、B相、C相)和中性(xing)線(xian)(xian)N同時穿過同一(yi)剩余(yu)電(dian)(dian)(dian)流(liu)(liu)探(tan)測(ce)器(qi)(qi)來(lai)進行工作的(de)(de)。因(yin)此剩余(yu)電(dian)(dian)(dian)流(liu)(liu)式電(dian)(dian)(dian)氣火災監(jian)控(kong)探(tan)測(ce)器(qi)(qi)安裝(zhuang)時,三相相線(xian)(xian)及中性(xing)線(xian)(xian)必(bi)須一(yi)起(qi)穿過探(tan)測(ce)器(qi)(qi),PE線(xian)(xian)禁(jin)止穿過探(tan)測(ce)器(qi)(qi);安裝(zhuang)剩余(yu)電(dian)(dian)(dian)流(liu)(liu)式電(dian)(dian)(dian)氣火災監(jian)控(kong)探(tan)測(ce)器(qi)(qi)后,應滿足原有電(dian)(dian)(dian)氣設備的(de)(de)絕(jue)緣標準。
剩余電流互感器在(zai)沒有特殊情況下應該接入(ru)A、B、C、N四條線路。
剩(sheng)余(yu)電(dian)流互(hu)(hu)感器(qi)在安(an)裝(zhuang)時,必須將(jiang)PE線(xian)(xian)(xian)和(he)N線(xian)(xian)(xian)嚴格區分開,PE線(xian)(xian)(xian)不(bu)可接(jie)入(ru)剩(sheng)余(yu)電(dian)流互(hu)(hu)感器(qi)。N線(xian)(xian)(xian)應接(jie)入(ru)互(hu)(hu)感器(qi),而穿過剩(sheng)余(yu)電(dian)流互(hu)(hu)感器(qi)的(de)N線(xian)(xian)(xian)及(ji)接(jie)入(ru)剩(sheng)余(yu)電(dian)流互(hu)(hu)感器(qi)負荷側(ce)的(de)N線(xian)(xian)(xian),僅作(zuo)(zuo)為(wei)中性線(xian)(xian)(xian),不(bu)能(neng)(neng)重(zhong)復多點接(jie)地,不(bu)能(neng)(neng)作(zuo)(zuo)為(wei)PE線(xian)(xian)(xian)使(shi)用(yong),不(bu)能(neng)(neng)接(jie)設備外(wai)殼。并且不(bu)得再與其(qi)他回路(lu)共用(yong)。
根(gen)據規范對(dui)電(dian)氣火(huo)災監控探(tan)測器的(de)定(ding)義,它的(de)任務僅在于(yu)防范電(dian)氣火(huo)災,而且僅用于(yu)報警,不切斷保護對(dui)象的(de)供電(dian)電(dian)源。它與剩余電(dian)流(liu)動作(zuo)斷路(lu)器,在防護功(gong)能、技(ji)術參數、結(jie)構(gou)要求(qiu)等方(fang)面有(you)很大區別。剩余電(dian)流(liu)動作(zuo)斷路(lu)器更(geng)側重(zhong)于(yu)人身安全的(de)防護。兩(liang)者應當配合起來使用,且不能相(xiang)互(hu)替代。
在一些斷(duan)(duan)路(lu)器(qi)切(qie)斷(duan)(duan)故障電(dian)(dian)(dian)氣回路(lu)而停(ting)電(dian)(dian)(dian),或許(xu)造(zao)成重(zhong)大(da)經(jing)濟損失及產生(sheng)不(bu)良社會影響的(de)設(she)備、場所,如公共(gong)場所的(de)通道(dao)照明電(dian)(dian)(dian)源(yuan)(yuan)與應急電(dian)(dian)(dian)源(yuan)(yuan)、消(xiao)防設(she)備的(de)電(dian)(dian)(dian)源(yuan)(yuan)、不(bu)允許(xu)停(ting)電(dian)(dian)(dian)的(de)特殊設(she)備等就不(bu)適(shi)宜安裝(zhuang)使用剩余(yu)電(dian)(dian)(dian)流動作(zuo)斷(duan)(duan)路(lu)器(qi),而應當(dang)使用安裝(zhuang)剩余(yu)電(dian)(dian)(dian)流監控探測器(qi)。