DZ20系列塑料外殼式斷路器(以下簡(jiǎn)稱斷路器),其額定絕緣電壓為660V,交流50Hz額定工作電壓380(400)V及以下，其額定電流從16A至1250A.一般作為配電用,其中Y、J、G型的額定電流225A及以下和400Y型的斷路器亦可作為保護(hù)電動(dòng)機(jī)用.在正常情況下,斷路器可分別作為線路不頻繁轉(zhuǎn)換及電動(dòng)機(jī)的不頻繁起動(dòng)之用. 四級(jí)斷路器主要用于交流50Hz、額定電壓400V及以下，額定電流16A至630A三相四線制的系統(tǒng)中，它能保證用戶和電源完全斷開(kāi)，確保安全，從而解決三極斷路器的不可克服的中性極電流不為零的弊端．　配電用斷路器，在配電網(wǎng)絡(luò)中用來(lái)分配電能，且可作為線路及電源設(shè)備的過(guò)載，短路和欠電壓保護(hù)．　保護(hù)電動(dòng)機(jī)用斷路器在配電網(wǎng)絡(luò)中用作鼠籠型電動(dòng)機(jī)的起動(dòng)和運(yùn)轉(zhuǎn)中分?jǐn)嘁约白鳂I(yè)電動(dòng)機(jī)的過(guò)載．2、型號(hào)及含義 附件名稱無(wú)報(bào)警觸頭分勵(lì)脫扣器二組輔助觸頭欠電壓脫扣器分勵(lì)脫扣器二組輔助觸頭分勵(lì)脫扣器欠電壓脫扣器四組輔助觸頭二組輔助觸頭欠電壓脫扣器欠電壓脫扣器報(bào)警觸頭二組輔助觸頭報(bào)警觸頭欠電壓脫扣器報(bào)警觸頭二組分勵(lì)脫扣器輔助觸頭報(bào)警觸頭分勵(lì)脫扣器欠電壓脫扣器報(bào)警觸頭四組輔助觸頭報(bào)警觸頭二組輔助觸頭欠電壓脫扣器報(bào)警觸頭瞬時(shí)脫扣器附件代號(hào)200208210220230240250260270218228238248258268278復(fù)式脫扣器附件代號(hào)3003083103203303403503603703183283383483583683783、過(guò)電流脫扣特性表殼架等級(jí)額定電流ImmA 約定發(fā)熱電流IthA短路分?jǐn)嗄芰?jí)別短路分?jǐn)嗄芰A（有效值）斷路器額定電流InAIcu/COS Icu/COS 160160C12/0.30-16,20,25,32,40,50,63,80,100,125,160100100Y18/0.3014/0.3016,20,25,32,40,50,63,80,100100100J35/0.2518/0.3016,20,25,32,40,50,63,80,100100250G100/0.2050/0.2516,20,25,32,40,50,63,80,100250225C15/0.30-100,125,160,180,200,225,250225225Y25/0.2519/0.30100,125,160,180,200,225225225J42/0.2525/0.25100,125,160,180,200,225225225G100/0.2050/0.25100,125,160,180,200,225400400C20/0.30-100,125,160,180,200,225,250,315,350,400400400Y30/0.2523/0.25200,225,250,315,350,400400400J42/0.2525/0.25200,225,250,315,350,400400400G100/0.2050/0.25200,225,250,315,350,400630630C20/0.30-400,500,630630630Y30/0.2523/0.25400,500,630630630J50/0.2525/0.25400,500,63012501250Y50/0.2532.5/0.25630,700,800,1000,125012501250J65/0.2032.5/0.25800,1000,1250