【熱繼(ji)(ji)電器(qi)】熱繼(ji)(ji)電器(qi)工(gong)作原理 熱繼(ji)(ji)電器(qi)型號(hao) 熱繼(ji)(ji)電器(qi)的作用

一、熱繼電器工作原理

熱繼電器是用于電動機或其它電氣設備、電氣線路的過(guo)載保護的保護電器。

電(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)(ji)(ji)(ji)在實(shi)際運行中(zhong)，如拖動(dong)(dong)(dong)生產機(ji)(ji)(ji)(ji)(ji)械(xie)進(jin)行工作過(guo)(guo)程(cheng)中(zhong)，若(ruo)機(ji)(ji)(ji)(ji)(ji)械(xie)出現(xian)不(bu)正常的(de)(de)情(qing)況或電(dian)(dian)路異常使電(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)(ji)(ji)(ji)遇到過(guo)(guo)載(zai)(zai)(zai)，則電(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)(ji)(ji)(ji)轉速(su)下降、繞(rao)(rao)組(zu)中(zhong)的(de)(de)電(dian)(dian)流將增大(da)(da)(da)，使電(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)(ji)(ji)(ji)的(de)(de)繞(rao)(rao)組(zu)溫度升高。若(ruo)過(guo)(guo)載(zai)(zai)(zai)電(dian)(dian)流不(bu)大(da)(da)(da)且過(guo)(guo)載(zai)(zai)(zai)的(de)(de)時(shi)(shi)間較(jiao)短，電(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)(ji)(ji)(ji)繞(rao)(rao)組(zu)不(bu)超過(guo)(guo)允(yun)許(xu)(xu)溫升，這(zhe)種(zhong)過(guo)(guo)載(zai)(zai)(zai)是(shi)允(yun)許(xu)(xu)的(de)(de)。但(dan)若(ruo)過(guo)(guo)載(zai)(zai)(zai)時(shi)(shi)間長，過(guo)(guo)載(zai)(zai)(zai)電(dian)(dian)流大(da)(da)(da)，電(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)(ji)(ji)(ji)繞(rao)(rao)組(zu)的(de)(de)溫升就會(hui)超過(guo)(guo)允(yun)許(xu)(xu)值(zhi)，使電(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)(ji)(ji)(ji)繞(rao)(rao)組(zu)老化(hua)，縮(suo)短電(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)(ji)(ji)(ji)的(de)(de)使用壽命(ming)，嚴(yan)重時(shi)(shi)甚至會(hui)使電(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)(ji)(ji)(ji)繞(rao)(rao)組(zu)燒毀。所以，這(zhe)種(zhong)過(guo)(guo)載(zai)(zai)(zai)是(shi)電(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)(ji)(ji)(ji)不(bu)能承(cheng)受的(de)(de)。熱(re)繼電(dian)(dian)器(qi)就是(shi)利用電(dian)(dian)流的(de)(de)熱(re)效應原理，在出現(xian)電(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)(ji)(ji)(ji)不(bu)能承(cheng)受的(de)(de)過(guo)(guo)載(zai)(zai)(zai)時(shi)(shi)切斷電(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)(ji)(ji)(ji)電(dian)(dian)路，為電(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)(ji)(ji)(ji)提供過(guo)(guo)載(zai)(zai)(zai)保護的(de)(de)保護電(dian)(dian)器(qi)。

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使(shi)用熱(re)繼電(dian)(dian)(dian)器對電(dian)(dian)(dian)動(dong)(dong)機(ji)(ji)進行過(guo)(guo)載保護時，將(jiang)熱(re)元件(jian)與電(dian)(dian)(dian)動(dong)(dong)機(ji)(ji)的(de)(de)定(ding)(ding)子繞組串(chuan)聯，將(jiang)熱(re)繼電(dian)(dian)(dian)器的(de)(de)常閉觸頭串(chuan)聯在交流接觸器的(de)(de)電(dian)(dian)(dian)磁線圈(quan)的(de)(de)控制電(dian)(dian)(dian)路中，并調(diao)(diao)節(jie)整(zheng)定(ding)(ding)電(dian)(dian)(dian)流調(diao)(diao)節(jie)旋(xuan)鈕，使(shi)人字形撥桿(gan)與推(tui)桿(gan)相距一適當距離。當電(dian)(dian)(dian)動(dong)(dong)機(ji)(ji)正(zheng)常工作時，通過(guo)(guo)熱(re)元件(jian)的(de)(de)電(dian)(dian)(dian)流即為(wei)電(dian)(dian)(dian)動(dong)(dong)機(ji)(ji)的(de)(de)額(e)定(ding)(ding)電(dian)(dian)(dian)流，熱(re)元件(jian)發(fa)熱(re)，雙金屬片受熱(re)后彎曲，使(shi)推(tui)桿(gan)剛好與人字形撥桿(gan)接觸，而又不能推(tui)動(dong)(dong)人字形撥桿(gan)。常閉觸頭處(chu)于閉合狀態，交流接觸器保持(chi)吸合，電(dian)(dian)(dian)動(dong)(dong)機(ji)(ji)正(zheng)常運行。

若(ruo)電(dian)(dian)(dian)動(dong)(dong)機出現過載情況，繞(rao)組中電(dian)(dian)(dian)流(liu)增大，通(tong)過熱繼電(dian)(dian)(dian)器元件(jian)中的電(dian)(dian)(dian)流(liu)增大使(shi)(shi)雙金屬片溫度升(sheng)得更(geng)高(gao)，彎曲程度加大，推(tui)(tui)動(dong)(dong)人字(zi)形(xing)撥桿(gan)，人字(zi)形(xing)撥桿(gan)推(tui)(tui)動(dong)(dong)常(chang)閉(bi)觸頭，使(shi)(shi)觸頭斷(duan)開(kai)而斷(duan)開(kai)交流(liu)接觸器線圈電(dian)(dian)(dian)路，使(shi)(shi)接觸器釋放(fang)、切斷(duan)電(dian)(dian)(dian)動(dong)(dong)機的電(dian)(dian)(dian)源，電(dian)(dian)(dian)動(dong)(dong)機停車(che)而得到(dao)保護(hu)。

螺(luo)(luo)(luo)釘(ding)8是常(chang)閉觸(chu)頭(tou)復(fu)(fu)位(wei)(wei)(wei)方式(shi)調(diao)節(jie)(jie)螺(luo)(luo)(luo)釘(ding)。當(dang)螺(luo)(luo)(luo)釘(ding)位(wei)(wei)(wei)置靠左時(shi)，電(dian)動(dong)(dong)(dong)(dong)機(ji)過載后，常(chang)閉觸(chu)頭(tou)斷(duan)開，電(dian)動(dong)(dong)(dong)(dong)機(ji)停車后，熱(re)繼電(dian)器雙金屬(shu)片(pian)冷卻復(fu)(fu)位(wei)(wei)(wei)。常(chang)閉觸(chu)頭(tou)的動(dong)(dong)(dong)(dong)觸(chu)頭(tou)在彈簧的作用下會自動(dong)(dong)(dong)(dong)復(fu)(fu)位(wei)(wei)(wei)。此時(shi)熱(re)繼電(dian)器為自動(dong)(dong)(dong)(dong)復(fu)(fu)位(wei)(wei)(wei)狀態。將(jiang)(jiang)螺(luo)(luo)(luo)釘(ding)逆時(shi)針旋(xuan)轉向右(you)調(diao)到一定(ding)位(wei)(wei)(wei)置時(shi)，若這時(shi)電(dian)動(dong)(dong)(dong)(dong)機(ji)過載，熱(re)繼電(dian)器的常(chang)閉觸(chu)頭(tou)斷(duan)開。其動(dong)(dong)(dong)(dong)觸(chu)頭(tou)將(jiang)(jiang)擺(bai)到右(you)側一新的平衡位(wei)(wei)(wei)置。電(dian)動(dong)(dong)(dong)(dong)機(ji)斷(duan)電(dian)停車后，動(dong)(dong)(dong)(dong)觸(chu)頭(tou)不能(neng)(neng)復(fu)(fu)位(wei)(wei)(wei)。必須(xu)按動(dong)(dong)(dong)(dong)復(fu)(fu)位(wei)(wei)(wei)按鈕后動(dong)(dong)(dong)(dong)觸(chu)頭(tou)方能(neng)(neng)復(fu)(fu)位(wei)(wei)(wei)。此時(shi)熱(re)繼電(dian)器為手動(dong)(dong)(dong)(dong)復(fu)(fu)位(wei)(wei)(wei)狀態。若電(dian)動(dong)(dong)(dong)(dong)機(ji)過載是故障性的，為了避免再次(ci)輕易地起(qi)動(dong)(dong)(dong)(dong)電(dian)動(dong)(dong)(dong)(dong)機(ji)，熱(re)繼電(dian)器宜采(cai)用手動(dong)(dong)(dong)(dong)復(fu)(fu)位(wei)(wei)(wei)方式(shi)。若要將(jiang)(jiang)熱(re)繼電(dian)器由手動(dong)(dong)(dong)(dong)復(fu)(fu)位(wei)(wei)(wei)方式(shi)調(diao)至自動(dong)(dong)(dong)(dong)復(fu)(fu)位(wei)(wei)(wei)方式(shi)，只需將(jiang)(jiang)復(fu)(fu)位(wei)(wei)(wei)調(diao)節(jie)(jie)螺(luo)(luo)(luo)釘(ding)順時(shi)針旋(xuan)進至適(shi)當(dang)位(wei)(wei)(wei)置即可。

二、熱繼電器型號

NR2熱繼電器(qi)NR2-11.5/Z 0.1-13A、NR2熱繼電(dian)器NR2-25G/Z 0.1-10A、NR2熱繼電器NR2-25G/Z 13-25A、NR2熱繼電器NR2-36G/Z 23-36A、NR2熱(re)繼電器NR2-93G/Z 23-80A等。

熱繼電器選型方法：

1，熱繼電器(qi)的選擇應等于(yu)或大于(yu)電機的額定電流。

2，熱繼(ji)電(dian)(dian)器的(de)額定電(dian)(dian)流為電(dian)(dian)動(dong)機額定電(dian)(dian)流的(de)（0.95-1.05）倍。

3，對于電(dian)機(ji)電(dian)路(lu)，熱繼電(dian)器的整定(ding)電(dian)流(liu)應等(deng)于電(dian)機(ji)的額定(ding)電(dian)流(liu)。

4，當熱繼電器周圍的環境溫(wen)度不是35℃時，應該設定為(wei)：（95-T）/ 60平方t：環境溫(wen)度。

三、熱繼電器的作用

主要用來對異(yi)步電(dian)(dian)(dian)動(dong)(dong)(dong)機(ji)進(jin)行過(guo)載保(bao)(bao)(bao)護(hu)(hu)，他的(de)工(gong)作(zuo)(zuo)原理是過(guo)載電(dian)(dian)(dian)流通過(guo)熱(re)元(yuan)件后，使雙(shuang)金(jin)屬片加熱(re)彎(wan)曲去(qu)推動(dong)(dong)(dong)動(dong)(dong)(dong)作(zuo)(zuo)機(ji)構來帶(dai)動(dong)(dong)(dong)觸(chu)點動(dong)(dong)(dong)作(zuo)(zuo)，從而將電(dian)(dian)(dian)動(dong)(dong)(dong)機(ji)控制(zhi)電(dian)(dian)(dian)路斷開實(shi)現(xian)電(dian)(dian)(dian)動(dong)(dong)(dong)機(ji)斷電(dian)(dian)(dian)停車，起到過(guo)載保(bao)(bao)(bao)護(hu)(hu)的(de)作(zuo)(zuo)用。鑒(jian)于雙(shuang)金(jin)屬片受熱(re)彎(wan)曲過(guo)程中，熱(re)量的(de)傳遞需要較長的(de)時間，因此，熱(re)繼電(dian)(dian)(dian)器(qi)不能(neng)用作(zuo)(zuo)短路保(bao)(bao)(bao)護(hu)(hu)，而只能(neng)用作(zuo)(zuo)過(guo)載保(bao)(bao)(bao)護(hu)(hu)熱(re)繼電(dian)(dian)(dian)器(qi)的(de)過(guo)載保(bao)(bao)(bao)護(hu)(hu)。

熱繼電器其(qi)它部分的(de)(de)(de)作(zuo)用(yong)如下：人字(zi)形撥(bo)桿(gan)的(de)(de)(de)左臂(bei)也用(yong)雙金屬片制成(cheng)，當環(huan)境溫度發(fa)生變化時，主電(dian)路(lu)中的(de)(de)(de)雙金屬片會(hui)產生一定的(de)(de)(de)變形彎曲，這(zhe)時人字(zi)形撥(bo)桿(gan)的(de)(de)(de)左臂(bei)也會(hui)發(fa)生同方(fang)向的(de)(de)(de)變形彎曲，從而(er)使人字(zi)形撥(bo)桿(gan)與推桿(gan)之間的(de)(de)(de)距離基本保(bao)持不變，保(bao)證熱繼電(dian)器動(dong)作(zuo)的(de)(de)(de)準確性。這(zhe)種作(zuo)用(yong)稱溫度補償作(zuo)用(yong)。