【熱繼電(dian)(dian)器(qi)(qi)】熱繼電(dian)(dian)器(qi)(qi)工作(zuo)原理 熱繼電(dian)(dian)器(qi)(qi)型號 熱繼電(dian)(dian)器(qi)(qi)的作(zuo)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(qi)線路的過載保護的保護電器。

電(dian)(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)(ji)在實際運行中(zhong)，如拖動(dong)(dong)(dong)生產機(ji)(ji)(ji)械進(jin)行工作(zuo)過程中(zhong)，若(ruo)機(ji)(ji)(ji)械出現不(bu)(bu)(bu)正常的(de)情況或電(dian)(dian)(dian)路(lu)異常使(shi)電(dian)(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)(ji)遇(yu)到(dao)過載(zai)(zai)(zai)，則(ze)電(dian)(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)(ji)轉速下降(jiang)、繞(rao)組中(zhong)的(de)電(dian)(dian)(dian)流(liu)(liu)將增大，使(shi)電(dian)(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)(ji)的(de)繞(rao)組溫度升(sheng)高。若(ruo)過載(zai)(zai)(zai)電(dian)(dian)(dian)流(liu)(liu)不(bu)(bu)(bu)大且(qie)過載(zai)(zai)(zai)的(de)時(shi)(shi)間較短(duan)，電(dian)(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)(ji)繞(rao)組不(bu)(bu)(bu)超過允許溫升(sheng)，這(zhe)種過載(zai)(zai)(zai)是(shi)允許的(de)。但若(ruo)過載(zai)(zai)(zai)時(shi)(shi)間長，過載(zai)(zai)(zai)電(dian)(dian)(dian)流(liu)(liu)大，電(dian)(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)(ji)繞(rao)組的(de)溫升(sheng)就會超過允許值，使(shi)電(dian)(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)(ji)繞(rao)組老化，縮短(duan)電(dian)(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)(ji)的(de)使(shi)用壽命(ming)，嚴(yan)重時(shi)(shi)甚至會使(shi)電(dian)(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)(ji)繞(rao)組燒毀。所(suo)以(yi)，這(zhe)種過載(zai)(zai)(zai)是(shi)電(dian)(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)(ji)不(bu)(bu)(bu)能承受的(de)。熱繼電(dian)(dian)(dian)器(qi)(qi)就是(shi)利用電(dian)(dian)(dian)流(liu)(liu)的(de)熱效(xiao)應原理，在出現電(dian)(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)(ji)不(bu)(bu)(bu)能承受的(de)過載(zai)(zai)(zai)時(shi)(shi)切斷(duan)電(dian)(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)(ji)電(dian)(dian)(dian)路(lu)，為電(dian)(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)(ji)提供過載(zai)(zai)(zai)保護(hu)的(de)保護(hu)電(dian)(dian)(dian)器(qi)(qi)。

該圖片由注冊用戶"時間如梭"提供，版權聲明反饋

使(shi)用熱繼(ji)電器對電動機(ji)(ji)進行(xing)過載保護時(shi)，將(jiang)熱元(yuan)件與(yu)(yu)電動機(ji)(ji)的(de)定子(zi)繞組串聯(lian)，將(jiang)熱繼(ji)電器的(de)常閉(bi)觸(chu)(chu)頭串聯(lian)在交流(liu)接(jie)(jie)觸(chu)(chu)器的(de)電磁線圈的(de)控制電路(lu)中，并調節整定電流(liu)調節旋鈕，使(shi)人(ren)字形撥(bo)桿(gan)與(yu)(yu)推(tui)(tui)桿(gan)相距一適當距離。當電動機(ji)(ji)正常工(gong)作時(shi)，通過熱元(yuan)件的(de)電流(liu)即為電動機(ji)(ji)的(de)額定電流(liu)，熱元(yuan)件發(fa)熱，雙金屬片(pian)受熱后彎曲，使(shi)推(tui)(tui)桿(gan)剛(gang)好與(yu)(yu)人(ren)字形撥(bo)桿(gan)接(jie)(jie)觸(chu)(chu)，而又不(bu)能推(tui)(tui)動人(ren)字形撥(bo)桿(gan)。常閉(bi)觸(chu)(chu)頭處于閉(bi)合狀態，交流(liu)接(jie)(jie)觸(chu)(chu)器保持吸(xi)合，電動機(ji)(ji)正常運行(xing)。

若電(dian)(dian)動機(ji)出現過載情況，繞組(zu)中電(dian)(dian)流(liu)增(zeng)大，通過熱繼電(dian)(dian)器(qi)元件中的電(dian)(dian)流(liu)增(zeng)大使(shi)(shi)雙(shuang)金屬片溫(wen)度升得(de)更高，彎(wan)曲(qu)程(cheng)度加大，推動人(ren)(ren)字(zi)形(xing)撥桿(gan)，人(ren)(ren)字(zi)形(xing)撥桿(gan)推動常閉觸頭，使(shi)(shi)觸頭斷開而斷開交(jiao)流(liu)接(jie)觸器(qi)線圈(quan)電(dian)(dian)路，使(shi)(shi)接(jie)觸器(qi)釋放、切斷電(dian)(dian)動機(ji)的電(dian)(dian)源，電(dian)(dian)動機(ji)停車而得(de)到保護。

螺釘8是(shi)常閉觸(chu)(chu)頭(tou)(tou)(tou)(tou)復(fu)位(wei)(wei)(wei)(wei)方(fang)式(shi)調(diao)節(jie)螺釘。當螺釘位(wei)(wei)(wei)(wei)置靠左時(shi)(shi)，電(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)(dong)(dong)機過載(zai)后，常閉觸(chu)(chu)頭(tou)(tou)(tou)(tou)斷開，電(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)(dong)(dong)機停(ting)車后，熱(re)繼(ji)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)雙金屬片冷(leng)卻復(fu)位(wei)(wei)(wei)(wei)。常閉觸(chu)(chu)頭(tou)(tou)(tou)(tou)的(de)(de)動(dong)(dong)(dong)(dong)(dong)(dong)觸(chu)(chu)頭(tou)(tou)(tou)(tou)在(zai)彈(dan)簧的(de)(de)作用下會自動(dong)(dong)(dong)(dong)(dong)(dong)復(fu)位(wei)(wei)(wei)(wei)。此時(shi)(shi)熱(re)繼(ji)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)為自動(dong)(dong)(dong)(dong)(dong)(dong)復(fu)位(wei)(wei)(wei)(wei)狀態。將(jiang)(jiang)螺釘逆時(shi)(shi)針(zhen)旋轉向右調(diao)到(dao)(dao)一定位(wei)(wei)(wei)(wei)置時(shi)(shi)，若這(zhe)時(shi)(shi)電(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)(dong)(dong)機過載(zai)，熱(re)繼(ji)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)的(de)(de)常閉觸(chu)(chu)頭(tou)(tou)(tou)(tou)斷開。其動(dong)(dong)(dong)(dong)(dong)(dong)觸(chu)(chu)頭(tou)(tou)(tou)(tou)將(jiang)(jiang)擺到(dao)(dao)右側一新的(de)(de)平衡位(wei)(wei)(wei)(wei)置。電(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)(dong)(dong)機斷電(dian)(dian)(dian)(dian)(dian)停(ting)車后，動(dong)(dong)(dong)(dong)(dong)(dong)觸(chu)(chu)頭(tou)(tou)(tou)(tou)不能(neng)復(fu)位(wei)(wei)(wei)(wei)。必須(xu)按動(dong)(dong)(dong)(dong)(dong)(dong)復(fu)位(wei)(wei)(wei)(wei)按鈕后動(dong)(dong)(dong)(dong)(dong)(dong)觸(chu)(chu)頭(tou)(tou)(tou)(tou)方(fang)能(neng)復(fu)位(wei)(wei)(wei)(wei)。此時(shi)(shi)熱(re)繼(ji)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)為手動(dong)(dong)(dong)(dong)(dong)(dong)復(fu)位(wei)(wei)(wei)(wei)狀態。若電(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)(dong)(dong)機過載(zai)是(shi)故障性的(de)(de)，為了避(bi)免再次(ci)輕易地起動(dong)(dong)(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)(dong)(dong)機，熱(re)繼(ji)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)宜(yi)采(cai)用手動(dong)(dong)(dong)(dong)(dong)(dong)復(fu)位(wei)(wei)(wei)(wei)方(fang)式(shi)。若要(yao)將(jiang)(jiang)熱(re)繼(ji)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)由手動(dong)(dong)(dong)(dong)(dong)(dong)復(fu)位(wei)(wei)(wei)(wei)方(fang)式(shi)調(diao)至自動(dong)(dong)(dong)(dong)(dong)(dong)復(fu)位(wei)(wei)(wei)(wei)方(fang)式(shi)，只需將(jiang)(jiang)復(fu)位(wei)(wei)(wei)(wei)調(diao)節(jie)螺釘順時(shi)(shi)針(zhen)旋進至適(shi)當位(wei)(wei)(wei)(wei)置即可。

二、熱繼電器型號

NR2熱繼(ji)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(ji)電器NR2-36G/Z 23-36A、NR2熱(re)繼電器(qi)NR2-93G/Z 23-80A等(deng)。

熱繼電器選型方法(fa)：

1，熱(re)繼電器的選擇(ze)應等于或大于電機的額定電流。

2，熱繼(ji)電器的額定(ding)電流為電動機額定(ding)電流的（0.95-1.05）倍。

3，對于(yu)(yu)電機電路，熱繼電器的整定電流(liu)應等(deng)于(yu)(yu)電機的額定電流(liu)。

4，當熱繼電器周(zhou)圍的環境(jing)溫度(du)不是35℃時，應該設定為：（95-T）/ 60平方(fang)t：環境(jing)溫度。

三、熱繼電器的作用

主要(yao)用(yong)來(lai)對異步電(dian)(dian)動機(ji)(ji)(ji)進行過(guo)載(zai)保護(hu)，他(ta)的(de)工作(zuo)原理是過(guo)載(zai)電(dian)(dian)流(liu)通(tong)過(guo)熱(re)元(yuan)件后(hou)，使(shi)雙金屬片(pian)加熱(re)彎(wan)曲去推動動作(zuo)機(ji)(ji)(ji)構來(lai)帶動觸點動作(zuo)，從而(er)將電(dian)(dian)動機(ji)(ji)(ji)控(kong)制電(dian)(dian)路斷開(kai)實現電(dian)(dian)動機(ji)(ji)(ji)斷電(dian)(dian)停(ting)車，起(qi)到過(guo)載(zai)保護(hu)的(de)作(zuo)用(yong)。鑒于雙金屬片(pian)受熱(re)彎(wan)曲過(guo)程中，熱(re)量的(de)傳遞需要(yao)較長的(de)時間，因此，熱(re)繼電(dian)(dian)器不能用(yong)作(zuo)短路保護(hu)，而(er)只(zhi)能用(yong)作(zuo)過(guo)載(zai)保護(hu)熱(re)繼電(dian)(dian)器的(de)過(guo)載(zai)保護(hu)。

熱繼電器其(qi)它部分的作(zuo)用(yong)如下：人(ren)字形(xing)撥桿的左(zuo)(zuo)臂也(ye)用(yong)雙(shuang)金屬片制成，當環(huan)境溫度發生(sheng)變化時，主(zhu)電(dian)路中(zhong)的雙(shuang)金屬片會(hui)產生(sheng)一定(ding)的變形(xing)彎曲，這時人(ren)字形(xing)撥桿的左(zuo)(zuo)臂也(ye)會(hui)發生(sheng)同方向的變形(xing)彎曲，從(cong)而(er)使人(ren)字形(xing)撥桿與推(tui)桿之(zhi)間(jian)的距離(li)基本保持不變，保證熱繼電(dian)器動作(zuo)的準(zhun)確性。這種作(zuo)用(yong)稱溫度補償(chang)作(zuo)用(yong)。