冷庫壓縮機常見的故障及處理方法

一、電機燒毀

電動機壓縮機（以下簡(jian)稱壓縮機(ji)）的故障可分為電機(ji)故障和(he)機(ji)械故障（包(bao)括曲軸，連(lian)桿，活塞，閥片，缸蓋墊等）。

機械故(gu)障往(wang)往(wang)使電機超負荷運轉(zhuan)(zhuan)甚至堵(du)轉(zhuan)(zhuan)，是電機損壞的主要原因之一。

電(dian)機的(de)損壞(huai)(huai)主(zhu)要(yao)表現(xian)為(wei)定子繞(rao)組絕(jue)(jue)緣層破壞(huai)(huai)（短(duan)路）和斷路等。定子繞(rao)組損壞(huai)(huai)后很難及(ji)時被發現(xian)，最終可能導(dao)致(zhi)繞(rao)組燒毀(hui)(hui)(hui)。繞(rao)組燒毀(hui)(hui)(hui)后，掩(yan)蓋(gai)了一(yi)些導(dao)致(zhi)燒毀(hui)(hui)(hui)的(de)現(xian)象(xiang)或直接原因，使(shi)得事后分析和原因調查比較困難。然而，電(dian)機的(de)運(yun)轉離不開正(zheng)常(chang)的(de)電(dian)源輸入，合理(li)的(de)電(dian)機負荷，良好(hao)的(de)散熱和繞(rao)組漆(qi)包線絕(jue)(jue)緣層的(de)保(bao)護。

從這幾方面入手，不(bu)難發現繞組燒(shao)毀(hui)的(de)原因不(bu)外乎如下六種：

(1)異常(chang)負荷和(he)堵轉(zhuan)；

(2)金屬(shu)屑引起的繞組短路；

(3)接觸器問題(ti)；

(4)電源缺(que)相和電壓異常；

(5)冷卻不足；

(6)用壓縮機抽(chou)真空。

實際(ji)上，多種因(yin)素共同促成的電機損壞更為常(chang)見。

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二、異常負荷和堵轉

電機(ji)負(fu)(fu)荷包(bao)括壓縮氣體(ti)所需負(fu)(fu)荷以及克服機(ji)械摩擦所需負(fu)(fu)荷。

壓比過大，或壓差過大，會使壓縮過程更為困難；而潤滑失效引起的摩擦阻力增加，以及極端情況下的電機堵轉，將大大增加電機負荷。潤滑失效，摩擦阻力增大，是負荷異常的首要原因。回液稀釋潤滑油，潤(run)(run)滑(hua)油(you)(you)(you)(you)(you)過熱(re)，潤(run)(run)滑(hua)油(you)(you)(you)(you)(you)焦(jiao)(jiao)化變(bian)質，以(yi)及缺油(you)(you)(you)(you)(you)等(deng)都會(hui)破壞正常(chang)潤(run)(run)滑(hua)，導致潤(run)(run)滑(hua)失(shi)(shi)效。回(hui)液(ye)稀釋潤(run)(run)滑(hua)油(you)(you)(you)(you)(you)，影響摩擦(ca)(ca)(ca)面正常(chang)油(you)(you)(you)(you)(you)膜(mo)(mo)的(de)形成，甚至(zhi)(zhi)沖刷掉原有油(you)(you)(you)(you)(you)膜(mo)(mo)，增加摩擦(ca)(ca)(ca)和(he)磨(mo)損(sun)。壓縮機(ji)過熱(re)會(hui)引起使(shi)潤(run)(run)滑(hua)油(you)(you)(you)(you)(you)高(gao)(gao)溫(wen)變(bian)稀甚至(zhi)(zhi)焦(jiao)(jiao)化，影響正常(chang)油(you)(you)(you)(you)(you)膜(mo)(mo)的(de)形成。系統(tong)回(hui)油(you)(you)(you)(you)(you)不(bu)好，壓縮機(ji)缺油(you)(you)(you)(you)(you)，自然無法維持(chi)正常(chang)潤(run)(run)滑(hua)。曲(qu)(qu)軸高(gao)(gao)速旋轉，連桿活(huo)塞等(deng)高(gao)(gao)速運動，沒有油(you)(you)(you)(you)(you)膜(mo)(mo)保護(hu)的(de)摩擦(ca)(ca)(ca)面會(hui)迅速升溫(wen)，局部(bu)高(gao)(gao)溫(wen)使(shi)潤(run)(run)滑(hua)油(you)(you)(you)(you)(you)迅速蒸發或焦(jiao)(jiao)化，使(shi)該部(bu)位潤(run)(run)滑(hua)更加困難，數秒鐘內可引起局部(bu)嚴(yan)重磨(mo)損(sun)。潤(run)(run)滑(hua)失(shi)(shi)效，局部(bu)磨(mo)損(sun)，使(shi)曲(qu)(qu)軸轉動需要更大力矩。

小功(gong)率壓(ya)縮機(ji)(ji)（如冰箱，家用(yong)空調(diao)壓(ya)縮機(ji)(ji)）由于(yu)(yu)電(dian)(dian)(dian)機(ji)(ji)扭矩小，潤滑失效后常(chang)(chang)出現堵(du)(du)(du)轉(zhuan)(zhuan)（電(dian)(dian)(dian)機(ji)(ji)無法轉(zhuan)(zhuan)動(dong)(dong)(dong)）現象，并進入“堵(du)(du)(du)轉(zhuan)(zhuan)－熱保護(hu)－堵(du)(du)(du)轉(zhuan)(zhuan)”死循(xun)環(huan)，電(dian)(dian)(dian)機(ji)(ji)燒毀只是時(shi)間(jian)問(wen)題(ti)。而(er)(er)大(da)功(gong)率半封閉壓(ya)縮機(ji)(ji)電(dian)(dian)(dian)機(ji)(ji)扭矩很大(da)，局部磨損不會(hui)(hui)引(yin)起堵(du)(du)(du)轉(zhuan)(zhuan)，電(dian)(dian)(dian)機(ji)(ji)功(gong)率會(hui)(hui)在(zai)一(yi)定范圍內隨負荷(he)(he)而(er)(er)增(zeng)大(da)，從(cong)而(er)(er)引(yin)起更為嚴重(zhong)的(de)(de)磨損，甚至引(yin)起咬(yao)缸（活塞(sai)卡在(zai)氣缸內），連桿(gan)斷裂等嚴重(zhong)損壞(huai)。堵(du)(du)(du)轉(zhuan)(zhuan)時(shi)的(de)(de)電(dian)(dian)(dian)流（堵(du)(du)(du)轉(zhuan)(zhuan)電(dian)(dian)(dian)流）大(da)約(yue)是正常(chang)(chang)運行電(dian)(dian)(dian)流的(de)(de)4－8倍(bei)。電(dian)(dian)(dian)機(ji)(ji)啟動(dong)(dong)(dong)瞬間(jian)，電(dian)(dian)(dian)流的(de)(de)峰值可接近或達到堵(du)(du)(du)轉(zhuan)(zhuan)電(dian)(dian)(dian)流。由于(yu)(yu)電(dian)(dian)(dian)阻放熱量與(yu)電(dian)(dian)(dian)流的(de)(de)平方成正比，啟動(dong)(dong)(dong)和(he)(he)堵(du)(du)(du)轉(zhuan)(zhuan)時(shi)的(de)(de)電(dian)(dian)(dian)流會(hui)(hui)使繞組(zu)迅速升溫(wen)。熱保護(hu)可以在(zai)堵(du)(du)(du)轉(zhuan)(zhuan)時(shi)保護(hu)電(dian)(dian)(dian)極，但一(yi)般不會(hui)(hui)有很快的(de)(de)響(xiang)應(ying)，不能(neng)(neng)阻止頻(pin)繁(fan)啟動(dong)(dong)(dong)等引(yin)起的(de)(de)繞組(zu)溫(wen)度(du)變(bian)化。頻(pin)繁(fan)啟動(dong)(dong)(dong)和(he)(he)異常(chang)(chang)負荷(he)(he)，使繞組(zu)經受高溫(wen)考驗，會(hui)(hui)降低漆包線的(de)(de)絕緣性(xing)能(neng)(neng)。此外(wai)，壓(ya)縮氣體所需負荷(he)(he)也(ye)會(hui)(hui)隨壓(ya)縮比增(zeng)大(da)和(he)(he)壓(ya)差增(zeng)大(da)而(er)(er)增(zeng)大(da)。

因此將(jiang)(jiang)高溫(wen)(wen)壓縮機(ji)用(yong)于低溫(wen)(wen)，或將(jiang)(jiang)低溫(wen)(wen)壓縮機(ji)用(yong)于高溫(wen)(wen)，都會影響電(dian)機(ji)負荷(he)和散熱，是不合(he)適的，會縮短電(dian)極(ji)使用(yong)壽命。繞(rao)組絕緣性能(neng)變差后，如果有其它因素（如金(jin)屬屑構成導電(dian)回路(lu)，酸(suan)性潤滑油(you)等）配(pei)合(he)，很(hen)容易引起(qi)短路(lu)而損壞。

三、金屬屑引起的繞組短路

繞組中夾(jia)雜(za)的金屬屑是短路和(he)接(jie)地絕緣(yuan)值(zhi)低的罪魁(kui)禍首。

壓縮機運轉時(shi)(shi)的(de)(de)(de)正(zheng)常振動(dong)，以及每(mei)次啟動(dong)時(shi)(shi)繞(rao)組受電(dian)磁力作用而(er)扭動(dong)，都會(hui)促使(shi)(shi)夾(jia)雜于(yu)繞(rao)組間的(de)(de)(de)金(jin)(jin)屬(shu)(shu)(shu)(shu)屑(xie)(xie)(xie)(xie)與繞(rao)組漆包(bao)線之間的(de)(de)(de)相對(dui)運動(dong)和(he)摩(mo)擦。棱角銳利的(de)(de)(de)金(jin)(jin)屬(shu)(shu)(shu)(shu)屑(xie)(xie)(xie)(xie)會(hui)劃傷漆包(bao)線絕緣層，引起(qi)短路(lu)。金(jin)(jin)屬(shu)(shu)(shu)(shu)屑(xie)(xie)(xie)(xie)的(de)(de)(de)來(lai)源包(bao)括(kuo)施工時(shi)(shi)留下(xia)的(de)(de)(de)銅管屑(xie)(xie)(xie)(xie)，焊渣，壓(ya)(ya)縮(suo)(suo)機(ji)(ji)(ji)(ji)內部(bu)磨損和(he)零部(bu)件損壞（比(bi)如(ru)(ru)閥片(pian)破碎）時(shi)(shi)掉下(xia)的(de)(de)(de)金(jin)(jin)屬(shu)(shu)(shu)(shu)屑(xie)(xie)(xie)(xie)等。對(dui)于(yu)全封(feng)(feng)閉(bi)壓(ya)(ya)縮(suo)(suo)機(ji)(ji)(ji)(ji)（包(bao)括(kuo)全封(feng)(feng)閉(bi)渦旋壓(ya)(ya)縮(suo)(suo)機(ji)(ji)(ji)(ji)），這些(xie)金(jin)(jin)屬(shu)(shu)(shu)(shu)屑(xie)(xie)(xie)(xie)或碎粒會(hui)落(luo)在(zai)(zai)繞(rao)組上。對(dui)于(yu)半封(feng)(feng)閉(bi)壓(ya)(ya)縮(suo)(suo)機(ji)(ji)(ji)(ji)，有些(xie)顆粒會(hui)隨氣(qi)(qi)(qi)(qi)體和(he)潤滑油(you)在(zai)(zai)系統中(zhong)流動(dong)，最后由于(yu)磁性聚(ju)集(ji)在(zai)(zai)繞(rao)組中(zhong)；而(er)有些(xie)金(jin)(jin)屬(shu)(shu)(shu)(shu)屑(xie)(xie)(xie)(xie)（比(bi)如(ru)(ru)軸承磨損以及電(dian)機(ji)(ji)(ji)(ji)轉子與定(ding)子磨損（掃(sao)膛）時(shi)(shi)產生(sheng)的(de)(de)(de)）會(hui)直(zhi)(zhi)接(jie)落(luo)在(zai)(zai)繞(rao)組上。繞(rao)組中(zhong)聚(ju)集(ji)了金(jin)(jin)屬(shu)(shu)(shu)(shu)屑(xie)(xie)(xie)(xie)后，發生(sheng)短路(lu)只是(shi)一個時(shi)(shi)間問題。需要特(te)別(bie)提請注(zhu)意的(de)(de)(de)是(shi)雙級(ji)(ji)壓(ya)(ya)縮(suo)(suo)機(ji)(ji)(ji)(ji)。在(zai)(zai)雙級(ji)(ji)壓(ya)(ya)縮(suo)(suo)機(ji)(ji)(ji)(ji)中(zhong)，回(hui)(hui)氣(qi)(qi)(qi)(qi)以及正(zheng)常的(de)(de)(de)回(hui)(hui)油(you)直(zhi)(zhi)接(jie)進入第(di)一級(ji)(ji)（低壓(ya)(ya)級(ji)(ji)）氣(qi)(qi)(qi)(qi)缸，壓(ya)(ya)縮(suo)(suo)后經(jing)中(zhong)壓(ya)(ya)管進入電(dian)機(ji)(ji)(ji)(ji)腔(qiang)冷卻繞(rao)組，然(ran)后和(he)普(pu)通單級(ji)(ji)壓(ya)(ya)縮(suo)(suo)機(ji)(ji)(ji)(ji)一樣(yang)，進入第(di)二(er)級(ji)(ji)（高壓(ya)(ya)級(ji)(ji)氣(qi)(qi)(qi)(qi)缸）。回(hui)(hui)氣(qi)(qi)(qi)(qi)中(zhong)帶有潤滑油(you)，已經(jing)使(shi)(shi)壓(ya)(ya)縮(suo)(suo)過程如(ru)(ru)履薄冰，如(ru)(ru)果再有回(hui)(hui)液，第(di)一級(ji)(ji)氣(qi)(qi)(qi)(qi)缸的(de)(de)(de)閥片(pian)很容易被(bei)打碎。碎閥片(pian)經(jing)中(zhong)壓(ya)(ya)管后可進入繞(rao)組。因此(ci)，雙級(ji)(ji)壓(ya)(ya)縮(suo)(suo)機(ji)(ji)(ji)(ji)比(bi)單級(ji)(ji)壓(ya)(ya)縮(suo)(suo)機(ji)(ji)(ji)(ji)更容易出現金(jin)(jin)屬(shu)(shu)(shu)(shu)屑(xie)(xie)(xie)(xie)引起(qi)的(de)(de)(de)電(dian)機(ji)(ji)(ji)(ji)短路(lu)。

不幸的事情往往湊(cou)到一(yi)(yi)塊，出問(wen)題(ti)的壓縮機(ji)在(zai)開機(ji)分(fen)析時(shi)聞道的常常是潤(run)(run)滑(hua)油的焦糊味(wei)。金屬面嚴重磨損時(shi)溫度是很高的，而潤(run)(run)滑(hua)油在(zai)175?C以上時(shi)開始(shi)焦化。系(xi)統(tong)中(zhong)如果有(you)較(jiao)多水分(fen)（真空(kong)抽得不理想(xiang)，潤(run)(run)滑(hua)油和制冷劑含(han)水量大(da)，負壓回氣管(guan)破裂后空(kong)氣進(jin)入(ru)等），潤(run)(run)滑(hua)油就可能(neng)出現(xian)酸性。酸性潤(run)(run)滑(hua)油會(hui)腐蝕銅(tong)管(guan)和繞(rao)組絕緣(yuan)層(ceng)，一(yi)(yi)方(fang)面，它會(hui)引起(qi)鍍(du)銅(tong)現(xian)象；另一(yi)(yi)方(fang)面，這種含(han)有(you)銅(tong)原子的酸性潤(run)(run)滑(hua)油的絕緣(yuan)性能(neng)很差，為繞(rao)組短路提供了條件。

四、接觸器問題

接觸器是電(dian)機控制(zhi)回路中重要部件之一，選型不(bu)合理可以毀(hui)壞最好的壓縮機。

按負載正確選(xuan)擇接觸(chu)(chu)器(qi)是極(ji)其重要(yao)的(de)(de)(de)。接觸(chu)(chu)器(qi)必須能滿(man)足苛刻的(de)(de)(de)條件，如快速循(xun)環，持續超載和低電壓。它們必須有足夠(gou)大(da)的(de)(de)(de)面積以(yi)散發(fa)負載電流(liu)(liu)所產生(sheng)的(de)(de)(de)熱量，觸(chu)(chu)點材(cai)料(liao)的(de)(de)(de)選(xuan)擇必須在啟動或(huo)堵(du)轉等大(da)電流(liu)(liu)情況(kuang)下(xia)能防止焊合(he)。為了安全可靠，壓縮機接觸(chu)(chu)器(qi)要(yao)同時斷開(kai)三(san)相(xiang)電路(lu)。谷輪公司不推薦斷開(kai)二相(xiang)電路(lu)的(de)(de)(de)方法。在美國，谷輪公司認(ren)可的(de)(de)(de)接觸(chu)(chu)器(qi)必須滿(man)足如下(xia)四項：

接(jie)觸(chu)器(qi)必須滿足ARI標準(zhun)780-78“專用接(jie)觸(chu)器(qi)標準(zhun)”規定的工作(zuo)和(he)測試(shi)準(zhun)則。

制造商必須保(bao)證(zheng)接觸器在(zai)室(shi)溫下(xia)，在(zai)最低銘牌電壓的80％時能閉合。

當使用單(dan)個接(jie)(jie)觸(chu)器時，接(jie)(jie)觸(chu)器額定電流必(bi)須大(da)于電機銘牌電流額定值(RLA).同時，接(jie)(jie)觸(chu)器必(bi)須能承受電機堵轉(zhuan)電流。如(ru)(ru)果接(jie)(jie)觸(chu)器下游(you)還有(you)其它負載(zai)，比如(ru)(ru)電機風(feng)扇(shan)等，也必(bi)須考慮(lv)。

當(dang)使(shi)用兩個接觸(chu)器(qi)時(shi)，每個接觸(chu)器(qi)的(de)分繞組堵轉額定值必須等于或(huo)大于壓縮機半(ban)繞組堵轉額定值。

接觸器的(de)(de)額定(ding)電流(liu)不能低于(yu)壓縮機銘牌(pai)上的(de)(de)額定(ding)電流(liu)。

規格(ge)小或質量低劣的(de)接(jie)(jie)觸器(qi)(qi)無法經(jing)受壓(ya)縮機(ji)啟(qi)動(dong)(dong)(dong)(dong)，堵轉和低電壓(ya)時的(de)大電流沖擊，容(rong)易(yi)出現(xian)單相(xiang)或多(duo)相(xiang)觸點抖動(dong)(dong)(dong)(dong),焊接(jie)(jie)甚(shen)至脫落(luo)的(de)現(xian)象，引(yin)起電機(ji)損(sun)壞。觸點抖動(dong)(dong)(dong)(dong)的(de)接(jie)(jie)觸器(qi)(qi)頻繁地啟(qi)停電機(ji)。電機(ji)頻繁啟(qi)動(dong)(dong)(dong)(dong)，巨大的(de)啟(qi)動(dong)(dong)(dong)(dong)電流和發熱,會加劇繞組(zu)絕(jue)緣(yuan)層的(de)老化(hua)。每次啟(qi)動(dong)(dong)(dong)(dong)時，磁性力矩使電機(ji)繞組(zu)有(you)微小的(de)移動(dong)(dong)(dong)(dong)和相(xiang)互摩擦。如果(guo)有(you)其它因素配(pei)合（如金屬屑，絕(jue)緣(yuan)性差的(de)潤滑油等），很容(rong)易(yi)引(yin)起繞組(zu)間短路。熱保護系統并未設(she)計(ji)成(cheng)能防止這種(zhong)毀壞。此外(wai)，抖動(dong)(dong)(dong)(dong)的(de)接(jie)(jie)觸器(qi)(qi)線圈容(rong)易(yi)失效。如果(guo)有(you)接(jie)(jie)觸線圈損(sun)壞，容(rong)易(yi)出現(xian)單相(xiang)狀態。

如(ru)(ru)果接觸器選型偏小(xiao)，觸頭不能(neng)承受(shou)電(dian)(dian)弧和(he)由于頻繁開停循(xun)環(huan)或(huo)不穩定控(kong)(kong)制(zhi)(zhi)回(hui)路電(dian)(dian)壓(ya)產生(sheng)的(de)(de)高溫，可能(neng)焊合(he)或(huo)從觸頭架中脫落。焊合(he)的(de)(de)觸頭將(jiang)產生(sheng)永久性單相狀(zhuang)態(tai)，使過(guo)載保護(hu)器持(chi)續地循(xun)環(huan)接通和(he)斷(duan)開，需要(yao)特別強調的(de)(de)是(shi)，接觸器觸點焊合(he)后(hou)，依賴接觸器斷(duan)開壓(ya)縮機電(dian)(dian)源回(hui)路的(de)(de)所有控(kong)(kong)制(zhi)(zhi)（比如(ru)(ru)高低壓(ya)控(kong)(kong)制(zhi)(zhi)，油壓(ya)控(kong)(kong)制(zhi)(zhi)，融霜控(kong)(kong)制(zhi)(zhi)等）將(jiang)全部失效，壓(ya)縮機處于無保護(hu)狀(zhuang)態(tai)。

因此，當電機(ji)燒毀后，檢查接觸器是必不(bu)可少的(de)工序。接觸器是導致電機(ji)損壞的(de)一個常常被(bei)人(ren)遺忘的(de)重(zhong)要原因。

五、電源缺相和電壓異常

電(dian)壓不(bu)正常和缺相可以輕而易(yi)舉(ju)地毀掉任何電(dian)機。

電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)變化范圍(wei)不(bu)(bu)(bu)(bu)(bu)(bu)能超過(guo)(guo)額(e)定(ding)(ding)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)的(de)(de)(de)(de)(de)±10%。三(san)(san)相(xiang)(xiang)(xiang)(xiang)間(jian)的(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)不(bu)(bu)(bu)(bu)(bu)(bu)平(ping)衡(heng)(heng)不(bu)(bu)(bu)(bu)(bu)(bu)能超過(guo)(guo)5％。大(da)功率電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)必須(xu)獨立供電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，以(yi)(yi)防同線其(qi)他(ta)大(da)功率設備(bei)啟動和運(yun)轉(zhuan)(zhuan)時(shi)造(zao)成低電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)。電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源線必須(xu)能夠承載電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)的(de)(de)(de)(de)(de)額(e)定(ding)(ding)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)。如果發生缺相(xiang)(xiang)(xiang)(xiang)時(shi)壓(ya)(ya)(ya)(ya)(ya)(ya)縮(suo)機(ji)正(zheng)(zheng)在(zai)運(yun)轉(zhuan)(zhuan)，它將繼續運(yun)行(xing)但會(hui)(hui)(hui)有(you)大(da)的(de)(de)(de)(de)(de)負載電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)。電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)繞(rao)組(zu)會(hui)(hui)(hui)很快過(guo)(guo)熱，正(zheng)(zheng)常情況下(xia)壓(ya)(ya)(ya)(ya)(ya)(ya)縮(suo)機(ji)會(hui)(hui)(hui)被(bei)熱保護(hu)。當電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)繞(rao)組(zu)冷卻(que)至設定(ding)(ding)溫度，接(jie)觸器(qi)會(hui)(hui)(hui)閉(bi)合(he)，但壓(ya)(ya)(ya)(ya)(ya)(ya)縮(suo)機(ji)啟動不(bu)(bu)(bu)(bu)(bu)(bu)起來，出(chu)現堵(du)(du)轉(zhuan)(zhuan)，并進入“堵(du)(du)轉(zhuan)(zhuan)－熱保護(hu)－堵(du)(du)轉(zhuan)(zhuan)”死循環。現代電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)繞(rao)組(zu)的(de)(de)(de)(de)(de)差(cha)別非常小(xiao)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源三(san)(san)相(xiang)(xiang)(xiang)(xiang)平(ping)衡(heng)(heng)時(shi)相(xiang)(xiang)(xiang)(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)的(de)(de)(de)(de)(de)差(cha)別可(ke)以(yi)(yi)忽略。理想狀態(tai)下(xia)，相(xiang)(xiang)(xiang)(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)始(shi)終相(xiang)(xiang)(xiang)(xiang)等，只要在(zai)任一(yi)(yi)(yi)相(xiang)(xiang)(xiang)(xiang)上(shang)接(jie)一(yi)(yi)(yi)個(ge)保護(hu)器(qi)就可(ke)以(yi)(yi)防止過(guo)(guo)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)造(zao)成的(de)(de)(de)(de)(de)損(sun)壞(huai)。實(shi)際上(shang)很難保證相(xiang)(xiang)(xiang)(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)的(de)(de)(de)(de)(de)平(ping)衡(heng)(heng)。電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)不(bu)(bu)(bu)(bu)(bu)(bu)平(ping)衡(heng)(heng)百分數(shu)(shu)計(ji)算方法為(wei)，相(xiang)(xiang)(xiang)(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)與三(san)(san)相(xiang)(xiang)(xiang)(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)平(ping)均值(zhi)的(de)(de)(de)(de)(de)最大(da)偏差(cha)值(zhi)與三(san)(san)相(xiang)(xiang)(xiang)(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)平(ping)均值(zhi)比值(zhi)。例(li)(li)如，標稱380V三(san)(san)相(xiang)(xiang)(xiang)(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源，在(zai)壓(ya)(ya)(ya)(ya)(ya)(ya)縮(suo)機(ji)接(jie)線端測量的(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)分別為(wei)380V、366V、400V。可(ke)以(yi)(yi)計(ji)算出(chu)三(san)(san)相(xiang)(xiang)(xiang)(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)平(ping)均值(zhi)382V，最大(da)偏差(cha)為(wei)20V,所以(yi)(yi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)不(bu)(bu)(bu)(bu)(bu)(bu)平(ping)衡(heng)(heng)百分數(shu)(shu)為(wei)5.2％。作為(wei)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)不(bu)(bu)(bu)(bu)(bu)(bu)平(ping)衡(heng)(heng)的(de)(de)(de)(de)(de)結果，在(zai)正(zheng)(zheng)常運(yun)行(xing)使負載電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)的(de)(de)(de)(de)(de)不(bu)(bu)(bu)(bu)(bu)(bu)平(ping)衡(heng)(heng)是電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)不(bu)(bu)(bu)(bu)(bu)(bu)平(ping)衡(heng)(heng)百分點(dian)數(shu)(shu)的(de)(de)(de)(de)(de)4－10倍。前例(li)(li)中，5.2％不(bu)(bu)(bu)(bu)(bu)(bu)平(ping)衡(heng)(heng)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)可(ke)能引起50％的(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)不(bu)(bu)(bu)(bu)(bu)(bu)平(ping)衡(heng)(heng)。美國(guo)國(guo)家電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)器(qi)制造(zao)商協會(hui)(hui)(hui)(NEMA)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)動機(ji)和發電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)標準出(chu)版物指出(chu)，由不(bu)(bu)(bu)(bu)(bu)(bu)平(ping)衡(heng)(heng)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)造(zao)成的(de)(de)(de)(de)(de)相(xiang)(xiang)(xiang)(xiang)繞(rao)組(zu)溫升百分比大(da)約是電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)不(bu)(bu)(bu)(bu)(bu)(bu)平(ping)衡(heng)(heng)百分點(dian)數(shu)(shu)平(ping)方的(de)(de)(de)(de)(de)兩倍。前例(li)(li)中電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)不(bu)(bu)(bu)(bu)(bu)(bu)平(ping)衡(heng)(heng)點(dian)數(shu)(shu)為(wei)5.2，繞(rao)組(zu)溫度增(zeng)加的(de)(de)(de)(de)(de)百分數(shu)(shu)為(wei)54％。結果是一(yi)(yi)(yi)相(xiang)(xiang)(xiang)(xiang)繞(rao)組(zu)過(guo)(guo)熱而(er)其(qi)他(ta)兩個(ge)繞(rao)組(zu)溫度正(zheng)(zheng)常。一(yi)(yi)(yi)份由U.L.(保險商實(shi)驗室，美國(guo))完成的(de)(de)(de)(de)(de)調查顯示，43％的(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)力公司允許(xu)3％的(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)不(bu)(bu)(bu)(bu)(bu)(bu)平(ping)衡(heng)(heng)，另(ling)有(you)30％的(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)力公司允許(xu)5％的(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)不(bu)(bu)(bu)(bu)(bu)(bu)平(ping)衡(heng)(heng)。

六、冷卻不足

功率較(jiao)大的(de)壓(ya)縮機一般都是(shi)回氣(qi)冷卻型的(de)。蒸發溫(wen)度越(yue)低(di)，系統質(zhi)量流往往越(yue)小(xiao)。

當蒸發(fa)溫(wen)度(du)很低時（超過(guo)制(zhi)造商的(de)(de)(de)(de)(de)規(gui)定），流量就(jiu)不(bu)(bu)足以冷(leng)(leng)卻(que)(que)電機(ji)(ji)(ji)，電機(ji)(ji)(ji)就(jiu)會(hui)在較高溫(wen)度(du)下(xia)運轉(zhuan)。空氣(qi)(qi)冷(leng)(leng)卻(que)(que)型壓(ya)(ya)縮(suo)機(ji)(ji)(ji)（一(yi)般不(bu)(bu)超過(guo)10HP）對回氣(qi)(qi)的(de)(de)(de)(de)(de)依(yi)賴性小，但對壓(ya)(ya)縮(suo)機(ji)(ji)(ji)環境(jing)溫(wen)度(du)和(he)冷(leng)(leng)卻(que)(que)風量有(you)明確要求。制(zhi)冷(leng)(leng)劑(ji)大(da)量泄漏也(ye)會(hui)造成系統質量流減小，電機(ji)(ji)(ji)的(de)(de)(de)(de)(de)冷(leng)(leng)卻(que)(que)也(ye)會(hui)受(shou)到(dao)影響。一(yi)些無(wu)人看管的(de)(de)(de)(de)(de)冷(leng)(leng)庫，往往要等到(dao)制(zhi)冷(leng)(leng)效果(guo)很差時才會(hui)發(fa)現制(zhi)冷(leng)(leng)劑(ji)大(da)量泄漏了(le)。電機(ji)(ji)(ji)過(guo)熱(re)后會(hui)出現頻繁(fan)保護，有(you)些用(yong)(yong)戶不(bu)(bu)深入(ru)檢查原因(yin)，甚至將熱(re)保護器短(duan)路，那是非(fei)常(chang)糟糕的(de)(de)(de)(de)(de)事(shi)情(qing)。過(guo)不(bu)(bu)了(le)多久，電機(ji)(ji)(ji)就(jiu)會(hui)燒(shao)掉。壓(ya)(ya)縮(suo)機(ji)(ji)(ji)都有(you)安全(quan)運行(xing)工況范圍。安全(quan)工況主要的(de)(de)(de)(de)(de)考慮因(yin)素就(jiu)是壓(ya)(ya)縮(suo)機(ji)(ji)(ji)和(he)電機(ji)(ji)(ji)的(de)(de)(de)(de)(de)負荷與冷(leng)(leng)卻(que)(que)。由于不(bu)(bu)同(tong)溫(wen)區的(de)(de)(de)(de)(de)壓(ya)(ya)縮(suo)機(ji)(ji)(ji)的(de)(de)(de)(de)(de)價格不(bu)(bu)同(tong)，過(guo)去國內冷(leng)(leng)凍(dong)行(xing)業超范圍使(shi)用(yong)(yong)壓(ya)(ya)縮(suo)機(ji)(ji)(ji)是比較常(chang)見(jian)的(de)(de)(de)(de)(de)。隨著專(zhuan)業知識的(de)(de)(de)(de)(de)增(zeng)長(chang)和(he)經濟條件的(de)(de)(de)(de)(de)改(gai)善，情(qing)況已(yi)明顯改(gai)善。