指除安裝面外(wai)，其它所有(you)(you)(you)側(ce)面都(dou)被封閉(bi)起來的(de)一種低壓開(kai)(kai)(kai)關(guan)(guan)柜(ju)(ju)。這種柜(ju)(ju)子的(de)開(kai)(kai)(kai)關(guan)(guan)、保護(hu)和監(jian)測控制(zhi)等(deng)電氣元件，均安裝在一個(ge)用鋼或絕(jue)緣(yuan)材料制(zhi)成的(de)封閉(bi)外(wai)殼內(nei)，可(ke)靠墻(qiang)或離墻(qiang)安裝。柜(ju)(ju)內(nei)每(mei)條回(hui)路之間(jian)可(ke)以(yi)不加隔離措施(shi)，也可(ke)以(yi)采用接(jie)地的(de)金(jin)屬板(ban)(ban)或絕(jue)緣(yuan)板(ban)(ban)進(jin)行隔離。通(tong)常門與主開(kai)(kai)(kai)關(guan)(guan)操作有(you)(you)(you)機械(xie)聯鎖。另外(wai)還有(you)(you)(you)防護(hu)式臺(tai)型開(kai)(kai)(kai)關(guan)(guan)柜(ju)(ju)（即控制(zhi)臺(tai)）】面板(ban)(ban)上裝有(you)(you)(you)控制(zhi)、測量、信號等(deng)電器。防護(hu)式開(kai)(kai)(kai)關(guan)(guan)柜(ju)(ju)主要用作工藝現場(chang)的(de)配電裝置(zhi)。

1.主(zhu)母線最(zui)大(da)額定電(dian)(dian)(dian)流(liu)(liu):主(zhu)母線最(zui)大(da)能(neng)夠(gou)(gou)承(cheng)載(zai)的(de)(de)電(dian)(dian)(dian)流(liu)(liu)的(de)(de)額定值(zhi)。2.額定短時(shi)耐受(shou)(shou)電(dian)(dian)(dian)流(liu)(liu):由生(sheng)(sheng)產(chan)廠(chang)家給出的(de)(de),成(cheng)(cheng)套(tao)(tao)設(she)備中(zhong)某條(tiao)電(dian)(dian)(dian)路在(zai)國(guo)家標準(zhun)GB7251.1-2005中(zhong)8.2.3規定的(de)(de)試(shi)驗條(tiao)件(jian)(jian)下能(neng)安全承(cheng)載(zai)的(de)(de)短時(shi)耐受(shou)(shou)電(dian)(dian)(dian)流(liu)(liu)方(fang)(fang)均根值(zhi)。3.峰值(zhi)短時(shi)耐受(shou)(shou)電(dian)(dian)(dian)流(liu)(liu):在(zai)規定試(shi)驗條(tiao)件(jian)(jian)下,生(sheng)(sheng)產(chan)廠(chang)家規定此電(dian)(dian)(dian)路能(neng)夠(gou)(gou)圓滿地(di)承(cheng)受(shou)(shou)的(de)(de)峰值(zhi)電(dian)(dian)(dian)流(liu)(liu)。4.外(wai)殼(ke)防護等(deng)級(ji):IEC60529-1989標準(zhun)由成(cheng)(cheng)套(tao)(tao)設(she)備提(ti)供的(de)(de)防止觸及帶電(dian)(dian)(dian)部件(jian)(jian),以及外(wai)來固體(ti)(ti)的(de)(de)侵(qin)入和液體(ti)(ti)的(de)(de)進(jin)入的(de)(de)等(deng)級(ji)。具體(ti)(ti)等(deng)級(ji)劃分(fen)詳見IEC60529標準(zhun)。5.內(nei)部分(fen)隔(ge)方(fang)(fang)式:根據IEC60529-1989標準(zhun),為保護人身安全,將(jiang)開關(guan)柜(ju)獨立劃分(fen)成(cheng)(cheng)幾個(ge)隔(ge)室的(de)(de)不同(tong)(tong)方(fang)(fang)式。不同(tong)(tong)型號(hao)的(de)(de)配電(dian)(dian)(dian)柜(ju)之間(jian)的(de)(de)技術(shu)參數都(dou)(dou)有很(hen)大(da)不同(tong)(tong),而進(jin)口(kou)配電(dian)(dian)(dian)柜(ju)的(de)(de)技術(shu)參數基本都(dou)(dou)優于國(guo)產(chan)配電(dian)(dian)(dian)柜(ju),但并不能(neng)認(ren)為進(jin)口(kou)配電(dian)(dian)(dian)柜(ju)就一定比(bi)國(guo)產(chan)配電(dian)(dian)(dian)柜(ju)好。

這類開(kai)關柜(ju)采用鋼板制(zhi)成(cheng)(cheng)封閉外殼(ke)，進(jin)出(chu)線(xian)回路的電(dian)器元(yuan)(yuan)(yuan)(yuan)件(jian)都安裝在可(ke)抽出(chu)的抽屜中，構成(cheng)(cheng)能(neng)完成(cheng)(cheng)某一類供(gong)(gong)電(dian)任務的功(gong)能(neng)單元(yuan)(yuan)(yuan)(yuan)。功(gong)能(neng)單元(yuan)(yuan)(yuan)(yuan)與母(mu)線(xian)或(huo)電(dian)纜之間，用接地的金屬(shu)板或(huo)塑料制(zhi)成(cheng)(cheng)的功(gong)能(neng)板隔開(kai)，形(xing)成(cheng)(cheng)母(mu)線(xian)、功(gong)能(neng)單元(yuan)(yuan)(yuan)(yuan)和(he)電(dian)纜三個區域(yu)。每(mei)個功(gong)能(neng)單元(yuan)(yuan)(yuan)(yuan)之間也有(you)隔離措(cuo)施。抽屜式開(kai)關柜(ju)有(you)較高(gao)的可(ke)靠性、安全(quan)性和(he)互換性，是(shi)(shi)比較先進(jin)的開(kai)關柜(ju)，開(kai)關柜(ju)多數(shu)是(shi)(shi)指抽屜式開(kai)關柜(ju)。它們適用于要求供(gong)(gong)電(dian)可(ke)靠性較高(gao)的工礦企業(ye)、高(gao)層(ceng)建筑，作為集中控(kong)制(zhi)的配(pei)電(dian)中心。

施工(gong)用(yong)電(dian)(dian)(dian)配(pei)電(dian)(dian)(dian)系統(tong)應(ying)設置總(zong)配(pei)電(dian)(dian)(dian)箱(xiang)(xiang)、分(fen)配(pei)電(dian)(dian)(dian)箱(xiang)(xiang)、開關箱(xiang)(xiang)，并按(an)照“總(zong)-分(fen)-開”順序(xu)作分(fen)級設置，并形成“三級配(pei)電(dian)(dian)(dian)”模式(shi)。施工(gong)用(yong)配(pei)電(dian)(dian)(dian)系統(tong)各配(pei)電(dian)(dian)(dian)箱(xiang)(xiang)、開關箱(xiang)(xiang)的(de)安裝位置要合理。總(zong)配(pei)電(dian)(dian)(dian)箱(xiang)(xiang)要盡量靠近(jin)變壓器或外電(dian)(dian)(dian)源(yuan)處，以便電(dian)(dian)(dian)源(yuan)的(de)引入。分(fen)配(pei)電(dian)(dian)(dian)箱(xiang)(xiang)應(ying)盡量安裝在用(yong)電(dian)(dian)(dian)設備(bei)或負(fu)荷相對集中的(de)中心地(di)帶，確(que)保(bao)三相負(fu)荷保(bao)持平衡。開關箱(xiang)(xiang)安裝的(de)位置應(ying)視現場情況和工(gong)況盡量靠近(jin)其控制的(de)用(yong)電(dian)(dian)(dian)設備(bei)。

在農網改造中當時由于需求的配電箱數量大、施工期短，配電箱廠需要有關低壓電器的供貨時間急且數量多，配電箱廠家因而產生了對產品質量的要求不嚴格的現象，訂做配電箱造成(cheng)了一些(xie)產品投(tou)入運行(xing)后不(bu)久就發生故障(zhang)。如有些(xie)型號交流接觸(chu)器(qi)在(zai)配電箱投(tou)運后不(bu)久，就因接觸(chu)器(qi)合(he)閘線圈燒(shao)壞，而無(wu)法運行(xing)。