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(yi)下簡稱壓(ya)縮機）的(de)故障可分為電機故障和機械故障（包(bao)括(kuo)曲(qu)軸(zhou)，連桿，活塞，閥片(pian)，缸蓋墊等(deng)）。

機(ji)(ji)械故(gu)障(zhang)往(wang)往(wang)使電機(ji)(ji)超負荷(he)運轉(zhuan)甚至堵轉(zhuan)，是電機(ji)(ji)損(sun)壞的(de)主要原因之(zhi)一。

電(dian)機的損壞(huai)主要表現為定子繞(rao)(rao)組(zu)絕緣層(ceng)破壞(huai)（短路(lu)）和斷路(lu)等。定子繞(rao)(rao)組(zu)損壞(huai)后很難及時被發(fa)現，最(zui)終可能導致繞(rao)(rao)組(zu)燒(shao)毀(hui)。繞(rao)(rao)組(zu)燒(shao)毀(hui)后，掩蓋(gai)了(le)一些導致燒(shao)毀(hui)的現象或直接(jie)原因，使得(de)事后分析和原因調查比較困難。然而，電(dian)機的運轉離不開正常的電(dian)源輸入，合理(li)的電(dian)機負(fu)荷，良好的散熱和繞(rao)(rao)組(zu)漆包線絕緣層(ceng)的保(bao)護(hu)。

從(cong)這幾方面入手，不(bu)難發現繞(rao)組燒(shao)毀的原因不(bu)外乎如(ru)下六種：

(1)異常負荷和堵轉；

(2)金屬屑引起的繞組(zu)短路(lu)；

(3)接(jie)觸器問題；

(4)電源缺相和電壓異常(chang)；

(5)冷卻不足；

(6)用壓縮機(ji)抽真空。

實際上，多種因素共(gong)同促成的(de)電(dian)機損壞更為常(chang)見(jian)。

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二、異常負荷和堵轉

電機(ji)負(fu)荷包括壓縮氣(qi)體所(suo)需(xu)負(fu)荷以及克服機(ji)械摩擦(ca)所(suo)需(xu)負(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)(run)滑油(you)(you)(you)(you)過(guo)熱(re)，潤(run)(run)(run)滑油(you)(you)(you)(you)焦化變質(zhi)，以(yi)及(ji)缺油(you)(you)(you)(you)等(deng)都會(hui)破壞正常(chang)(chang)潤(run)(run)(run)滑，導(dao)致潤(run)(run)(run)滑失效(xiao)。回(hui)液稀(xi)釋(shi)潤(run)(run)(run)滑油(you)(you)(you)(you)，影響(xiang)摩擦(ca)面(mian)正常(chang)(chang)油(you)(you)(you)(you)膜(mo)的形成(cheng)，甚(shen)至沖(chong)刷掉原(yuan)有油(you)(you)(you)(you)膜(mo)，增(zeng)加摩擦(ca)和磨損(sun)。壓縮機(ji)過(guo)熱(re)會(hui)引起(qi)使潤(run)(run)(run)滑油(you)(you)(you)(you)高溫(wen)變稀(xi)甚(shen)至焦化，影響(xiang)正常(chang)(chang)油(you)(you)(you)(you)膜(mo)的形成(cheng)。系(xi)統(tong)回(hui)油(you)(you)(you)(you)不好，壓縮機(ji)缺油(you)(you)(you)(you)，自然(ran)無法維持正常(chang)(chang)潤(run)(run)(run)滑。曲軸高速(su)旋轉，連(lian)桿(gan)活塞等(deng)高速(su)運動，沒有油(you)(you)(you)(you)膜(mo)保護(hu)的摩擦(ca)面(mian)會(hui)迅速(su)升溫(wen)，局部(bu)(bu)高溫(wen)使潤(run)(run)(run)滑油(you)(you)(you)(you)迅速(su)蒸發或焦化，使該(gai)部(bu)(bu)位潤(run)(run)(run)滑更加困難，數秒(miao)鐘內(nei)可引起(qi)局部(bu)(bu)嚴重磨損(sun)。潤(run)(run)(run)滑失效(xiao)，局部(bu)(bu)磨損(sun)，使曲軸轉動需要更大力(li)矩。

小功率壓(ya)縮(suo)(suo)機(ji)(ji)(ji)（如冰箱，家用空調壓(ya)縮(suo)(suo)機(ji)(ji)(ji)）由于(yu)電(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)扭矩小，潤滑失效(xiao)后常(chang)(chang)出現(xian)堵轉(zhuan)(zhuan)(zhuan)（電(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)無法轉(zhuan)(zhuan)(zhuan)動(dong)）現(xian)象，并進入(ru)“堵轉(zhuan)(zhuan)(zhuan)－熱(re)保護－堵轉(zhuan)(zhuan)(zhuan)”死循環，電(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)燒毀(hui)只是時(shi)間(jian)問題。而大(da)(da)(da)功率半封閉(bi)壓(ya)縮(suo)(suo)機(ji)(ji)(ji)電(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)扭矩很大(da)(da)(da)，局部磨損(sun)不會(hui)(hui)引起堵轉(zhuan)(zhuan)(zhuan)，電(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)功率會(hui)(hui)在一定(ding)范圍內(nei)(nei)隨負(fu)荷(he)而增(zeng)大(da)(da)(da)，從(cong)而引起更為嚴(yan)重的(de)(de)磨損(sun)，甚至(zhi)引起咬缸(gang)（活塞卡在氣(qi)缸(gang)內(nei)(nei)），連(lian)桿斷裂(lie)等嚴(yan)重損(sun)壞(huai)。堵轉(zhuan)(zhuan)(zhuan)時(shi)的(de)(de)電(dian)(dian)(dian)(dian)(dian)流（堵轉(zhuan)(zhuan)(zhuan)電(dian)(dian)(dian)(dian)(dian)流）大(da)(da)(da)約(yue)是正(zheng)(zheng)常(chang)(chang)運(yun)行(xing)電(dian)(dian)(dian)(dian)(dian)流的(de)(de)4－8倍。電(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)啟動(dong)瞬間(jian)，電(dian)(dian)(dian)(dian)(dian)流的(de)(de)峰值可(ke)接近或達到堵轉(zhuan)(zhuan)(zhuan)電(dian)(dian)(dian)(dian)(dian)流。由于(yu)電(dian)(dian)(dian)(dian)(dian)阻(zu)放熱(re)量與(yu)電(dian)(dian)(dian)(dian)(dian)流的(de)(de)平方成正(zheng)(zheng)比，啟動(dong)和堵轉(zhuan)(zhuan)(zhuan)時(shi)的(de)(de)電(dian)(dian)(dian)(dian)(dian)流會(hui)(hui)使繞(rao)組(zu)迅速升溫。熱(re)保護可(ke)以在堵轉(zhuan)(zhuan)(zhuan)時(shi)保護電(dian)(dian)(dian)(dian)(dian)極，但一般不會(hui)(hui)有很快的(de)(de)響應(ying)，不能(neng)阻(zu)止頻繁啟動(dong)等引起的(de)(de)繞(rao)組(zu)溫度(du)變(bian)化(hua)。頻繁啟動(dong)和異常(chang)(chang)負(fu)荷(he)，使繞(rao)組(zu)經受高溫考驗(yan)，會(hui)(hui)降(jiang)低漆包線的(de)(de)絕緣性(xing)能(neng)。此外(wai)，壓(ya)縮(suo)(suo)氣(qi)體所需負(fu)荷(he)也(ye)會(hui)(hui)隨壓(ya)縮(suo)(suo)比增(zeng)大(da)(da)(da)和壓(ya)差增(zeng)大(da)(da)(da)而增(zeng)大(da)(da)(da)。

因此將高(gao)溫(wen)(wen)壓(ya)縮機(ji)(ji)用(yong)于低(di)溫(wen)(wen)，或(huo)將低(di)溫(wen)(wen)壓(ya)縮機(ji)(ji)用(yong)于高(gao)溫(wen)(wen)，都會(hui)影響電(dian)機(ji)(ji)負荷和(he)散(san)熱，是不(bu)合適的，會(hui)縮短電(dian)極(ji)使用(yong)壽命(ming)。繞組(zu)絕緣性能變差后，如(ru)果有其它因素（如(ru)金屬(shu)屑構成(cheng)導電(dian)回路(lu)，酸(suan)性潤(run)滑油(you)等）配合，很(hen)容易引起短路(lu)而損壞。

三、金屬屑引起的繞組短路

繞組中夾雜的金(jin)屬(shu)屑(xie)是短路和(he)接地絕緣(yuan)值低的罪魁禍首。

壓縮機運轉時(shi)(shi)(shi)的(de)(de)正常振動(dong)，以及(ji)每次啟動(dong)時(shi)(shi)(shi)繞(rao)組(zu)(zu)受電(dian)磁力作(zuo)用而(er)扭動(dong)，都會(hui)(hui)促使(shi)夾雜于繞(rao)組(zu)(zu)間(jian)的(de)(de)金(jin)(jin)屬(shu)屑(xie)(xie)(xie)(xie)與繞(rao)組(zu)(zu)漆包(bao)線(xian)之間(jian)的(de)(de)相對(dui)運動(dong)和(he)摩擦。棱角銳(rui)利的(de)(de)金(jin)(jin)屬(shu)屑(xie)(xie)(xie)(xie)會(hui)(hui)劃(hua)傷漆包(bao)線(xian)絕緣層，引(yin)起(qi)(qi)短路。金(jin)(jin)屬(shu)屑(xie)(xie)(xie)(xie)的(de)(de)來源包(bao)括施工(gong)時(shi)(shi)(shi)留下(xia)的(de)(de)銅管(guan)屑(xie)(xie)(xie)(xie)，焊渣，壓(ya)(ya)(ya)(ya)縮(suo)機(ji)(ji)內部(bu)磨(mo)損(sun)(sun)和(he)零(ling)部(bu)件損(sun)(sun)壞（比(bi)如(ru)閥片破碎）時(shi)(shi)(shi)掉下(xia)的(de)(de)金(jin)(jin)屬(shu)屑(xie)(xie)(xie)(xie)等。對(dui)于全封(feng)閉壓(ya)(ya)(ya)(ya)縮(suo)機(ji)(ji)（包(bao)括全封(feng)閉渦(wo)旋(xuan)壓(ya)(ya)(ya)(ya)縮(suo)機(ji)(ji)），這(zhe)些金(jin)(jin)屬(shu)屑(xie)(xie)(xie)(xie)或碎粒會(hui)(hui)落在繞(rao)組(zu)(zu)上。對(dui)于半(ban)封(feng)閉壓(ya)(ya)(ya)(ya)縮(suo)機(ji)(ji)，有(you)些顆粒會(hui)(hui)隨氣(qi)體和(he)潤滑油在系統中(zhong)(zhong)流動(dong)，最后(hou)(hou)由于磁性聚(ju)集(ji)在繞(rao)組(zu)(zu)中(zhong)(zhong)；而(er)有(you)些金(jin)(jin)屬(shu)屑(xie)(xie)(xie)(xie)（比(bi)如(ru)軸承(cheng)磨(mo)損(sun)(sun)以及(ji)電(dian)機(ji)(ji)轉子與定子磨(mo)損(sun)(sun)（掃膛）時(shi)(shi)(shi)產生的(de)(de)）會(hui)(hui)直接落在繞(rao)組(zu)(zu)上。繞(rao)組(zu)(zu)中(zhong)(zhong)聚(ju)集(ji)了(le)金(jin)(jin)屬(shu)屑(xie)(xie)(xie)(xie)后(hou)(hou)，發生短路只是一(yi)個時(shi)(shi)(shi)間(jian)問題。需要特(te)別提請注意的(de)(de)是雙級(ji)(ji)(ji)壓(ya)(ya)(ya)(ya)縮(suo)機(ji)(ji)。在雙級(ji)(ji)(ji)壓(ya)(ya)(ya)(ya)縮(suo)機(ji)(ji)中(zhong)(zhong)，回氣(qi)以及(ji)正常的(de)(de)回油直接進入第(di)一(yi)級(ji)(ji)(ji)（低壓(ya)(ya)(ya)(ya)級(ji)(ji)(ji)）氣(qi)缸，壓(ya)(ya)(ya)(ya)縮(suo)后(hou)(hou)經中(zhong)(zhong)壓(ya)(ya)(ya)(ya)管(guan)進入電(dian)機(ji)(ji)腔冷卻(que)繞(rao)組(zu)(zu)，然后(hou)(hou)和(he)普通單級(ji)(ji)(ji)壓(ya)(ya)(ya)(ya)縮(suo)機(ji)(ji)一(yi)樣，進入第(di)二級(ji)(ji)(ji)（高(gao)壓(ya)(ya)(ya)(ya)級(ji)(ji)(ji)氣(qi)缸）。回氣(qi)中(zhong)(zhong)帶有(you)潤滑油，已(yi)經使(shi)壓(ya)(ya)(ya)(ya)縮(suo)過(guo)程如(ru)履薄(bo)冰，如(ru)果再有(you)回液，第(di)一(yi)級(ji)(ji)(ji)氣(qi)缸的(de)(de)閥片很容(rong)易被(bei)打碎。碎閥片經中(zhong)(zhong)壓(ya)(ya)(ya)(ya)管(guan)后(hou)(hou)可(ke)進入繞(rao)組(zu)(zu)。因此(ci)，雙級(ji)(ji)(ji)壓(ya)(ya)(ya)(ya)縮(suo)機(ji)(ji)比(bi)單級(ji)(ji)(ji)壓(ya)(ya)(ya)(ya)縮(suo)機(ji)(ji)更容(rong)易出現(xian)金(jin)(jin)屬(shu)屑(xie)(xie)(xie)(xie)引(yin)起(qi)(qi)的(de)(de)電(dian)機(ji)(ji)短路。

不(bu)幸的(de)(de)事(shi)情往(wang)往(wang)湊到一塊，出問題的(de)(de)壓縮機(ji)在開(kai)機(ji)分析時(shi)聞(wen)道的(de)(de)常(chang)常(chang)是潤(run)(run)滑(hua)油(you)的(de)(de)焦(jiao)糊味。金屬面嚴(yan)重磨(mo)損時(shi)溫度(du)是很高(gao)的(de)(de)，而潤(run)(run)滑(hua)油(you)在175?C以(yi)上時(shi)開(kai)始焦(jiao)化。系統中如(ru)果有較多水分（真(zhen)空抽得不(bu)理想(xiang)，潤(run)(run)滑(hua)油(you)和(he)制冷劑含水量大，負壓回氣管(guan)破裂(lie)后空氣進入等），潤(run)(run)滑(hua)油(you)就(jiu)可能出現酸性(xing)。酸性(xing)潤(run)(run)滑(hua)油(you)會腐蝕銅(tong)管(guan)和(he)繞組(zu)絕(jue)緣層，一方(fang)面，它會引起鍍銅(tong)現象；另一方(fang)面，這(zhe)種(zhong)含有銅(tong)原子的(de)(de)酸性(xing)潤(run)(run)滑(hua)油(you)的(de)(de)絕(jue)緣性(xing)能很差，為繞組(zu)短路(lu)提供了條件。

四、接觸器問題

接觸(chu)器是電機(ji)控制(zhi)回路(lu)中(zhong)重要(yao)部(bu)件(jian)之一，選型不合理可以毀壞最好的壓縮(suo)機(ji)。

按負載正確選擇接(jie)觸器(qi)是極其重要的(de)(de)(de)。接(jie)觸器(qi)必(bi)(bi)須能(neng)滿足(zu)苛刻的(de)(de)(de)條件，如快速循環(huan)，持續超(chao)載和(he)低電(dian)壓。它們必(bi)(bi)須有足(zu)夠(gou)大的(de)(de)(de)面積以散發(fa)負載電(dian)流所產(chan)生的(de)(de)(de)熱量，觸點材料的(de)(de)(de)選擇必(bi)(bi)須在(zai)啟動(dong)或堵轉等大電(dian)流情況下能(neng)防(fang)止焊(han)合。為(wei)了安全可靠，壓縮(suo)機(ji)接(jie)觸器(qi)要同時斷開三(san)相電(dian)路。谷輪公司不推薦斷開二相電(dian)路的(de)(de)(de)方(fang)法(fa)。在(zai)美國，谷輪公司認(ren)可的(de)(de)(de)接(jie)觸器(qi)必(bi)(bi)須滿足(zu)如下四項：

接觸器(qi)必須(xu)滿足ARI標準780-78“專用(yong)接觸器(qi)標準”規(gui)定的工作和(he)測試準則。

制造商必須保證(zheng)接觸器在室溫(wen)下，在最低銘(ming)牌電(dian)壓(ya)的80％時能閉合。

當(dang)使用(yong)單個接(jie)觸器(qi)時(shi)，接(jie)觸器(qi)額(e)定電(dian)流必(bi)須大于電(dian)機(ji)銘牌電(dian)流額(e)定值(zhi)(RLA).同時(shi)，接(jie)觸器(qi)必(bi)須能承(cheng)受電(dian)機(ji)堵轉電(dian)流。如果接(jie)觸器(qi)下(xia)游還有其它負載，比如電(dian)機(ji)風扇等(deng)，也必(bi)須考(kao)慮。

當使用兩(liang)個(ge)接(jie)觸(chu)器時，每個(ge)接(jie)觸(chu)器的分繞組堵轉(zhuan)額定(ding)值(zhi)必須等于或大于壓縮機半繞組堵轉(zhuan)額定(ding)值(zhi)。

接觸器的額(e)定(ding)電流(liu)(liu)不能(neng)低(di)于壓(ya)縮機銘牌(pai)上的額(e)定(ding)電流(liu)(liu)。

規格(ge)小或質(zhi)量低(di)劣的接觸器無法經受壓縮機(ji)啟(qi)動(dong)，堵(du)轉和(he)低(di)電壓時的大電流沖擊，容(rong)易(yi)出現單相或多相觸點(dian)(dian)抖(dou)動(dong),焊(han)接甚至脫落的現象(xiang)，引起電機(ji)損(sun)壞。觸點(dian)(dian)抖(dou)動(dong)的接觸器頻(pin)繁地啟(qi)停電機(ji)。電機(ji)頻(pin)繁啟(qi)動(dong)，巨大的啟(qi)動(dong)電流和(he)發熱,會加劇繞(rao)組絕(jue)緣層的老(lao)化。每(mei)次啟(qi)動(dong)時，磁(ci)性力矩使電機(ji)繞(rao)組有微小的移動(dong)和(he)相互(hu)摩擦(ca)。如果有其它因(yin)素配(pei)合（如金(jin)屬屑(xie)，絕(jue)緣性差的潤(run)滑油(you)等(deng)），很容(rong)易(yi)引起繞(rao)組間(jian)短路(lu)。熱保護系統并未設計成(cheng)能防(fang)止這種毀壞。此外，抖(dou)動(dong)的接觸器線圈容(rong)易(yi)失效。如果有接觸線圈損(sun)壞，容(rong)易(yi)出現單相狀態。

如果接(jie)(jie)(jie)觸(chu)器選型(xing)偏小，觸(chu)頭不能承受電(dian)弧和由于頻繁開停循環(huan)或不穩定控制(zhi)(zhi)回(hui)路(lu)電(dian)壓(ya)產生(sheng)的(de)(de)高溫，可能焊合或從觸(chu)頭架中脫落。焊合的(de)(de)觸(chu)頭將(jiang)產生(sheng)永久性單(dan)相(xiang)狀(zhuang)態，使過載保(bao)護器持(chi)續(xu)地循環(huan)接(jie)(jie)(jie)通和斷開，需要(yao)特(te)別強調的(de)(de)是，接(jie)(jie)(jie)觸(chu)器觸(chu)點焊合后，依賴接(jie)(jie)(jie)觸(chu)器斷開壓(ya)縮機(ji)電(dian)源回(hui)路(lu)的(de)(de)所有(you)控制(zhi)(zhi)（比如高低壓(ya)控制(zhi)(zhi)，油壓(ya)控制(zhi)(zhi)，融霜控制(zhi)(zhi)等）將(jiang)全部失效，壓(ya)縮機(ji)處于無保(bao)護狀(zhuang)態。

因此，當電機燒毀(hui)后，檢查接觸器(qi)是必不可少的工序。接觸器(qi)是導致電機損(sun)壞(huai)的一個常常被人(ren)遺忘(wang)的重要原因。

五、電源缺相和電壓異常

電壓不正常(chang)和缺相可以(yi)輕而易舉地(di)毀掉任何電機(ji)。

電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)變化范圍不(bu)(bu)(bu)能超過額(e)定(ding)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)的(de)(de)(de)(de)(de)±10%。三(san)相(xiang)間的(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)不(bu)(bu)(bu)平(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)(heng)(heng)不(bu)(bu)(bu)能超過5％。大(da)(da)(da)功率電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)必(bi)(bi)須獨(du)立供電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，以(yi)防同線其他大(da)(da)(da)功率設備啟(qi)動和運轉(zhuan)(zhuan)時(shi)造(zao)(zao)(zao)成(cheng)(cheng)低電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)。電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源線必(bi)(bi)須能夠承載電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)的(de)(de)(de)(de)(de)額(e)定(ding)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流。如果(guo)發(fa)生缺相(xiang)時(shi)壓(ya)(ya)(ya)(ya)(ya)縮(suo)機(ji)(ji)(ji)(ji)正(zheng)(zheng)在(zai)(zai)運轉(zhuan)(zhuan)，它將繼續運行(xing)但會有大(da)(da)(da)的(de)(de)(de)(de)(de)負載電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流。電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)繞(rao)(rao)組(zu)(zu)(zu)會很(hen)快過熱(re)(re)，正(zheng)(zheng)常(chang)情(qing)況(kuang)下(xia)(xia)壓(ya)(ya)(ya)(ya)(ya)縮(suo)機(ji)(ji)(ji)(ji)會被熱(re)(re)保(bao)護(hu)(hu)。當電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)繞(rao)(rao)組(zu)(zu)(zu)冷(leng)卻至設定(ding)溫度，接觸(chu)器會閉合(he)，但壓(ya)(ya)(ya)(ya)(ya)縮(suo)機(ji)(ji)(ji)(ji)啟(qi)動不(bu)(bu)(bu)起(qi)來，出(chu)現堵轉(zhuan)(zhuan)，并進入“堵轉(zhuan)(zhuan)－熱(re)(re)保(bao)護(hu)(hu)－堵轉(zhuan)(zhuan)”死循(xun)環。現代電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)繞(rao)(rao)組(zu)(zu)(zu)的(de)(de)(de)(de)(de)差別非常(chang)小，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源三(san)相(xiang)平(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)(heng)(heng)時(shi)相(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流的(de)(de)(de)(de)(de)差別可(ke)以(yi)忽略(lve)。理(li)想狀(zhuang)態(tai)下(xia)(xia)，相(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)始終相(xiang)等(deng)，只要(yao)在(zai)(zai)任一相(xiang)上接一個(ge)保(bao)護(hu)(hu)器就可(ke)以(yi)防止過電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流造(zao)(zao)(zao)成(cheng)(cheng)的(de)(de)(de)(de)(de)損(sun)壞。實際(ji)上很(hen)難保(bao)證相(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)的(de)(de)(de)(de)(de)平(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)(heng)(heng)。電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)不(bu)(bu)(bu)平(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)(heng)(heng)百(bai)(bai)分(fen)(fen)數(shu)計算方(fang)法為(wei)，相(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)與(yu)(yu)三(san)相(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)平(ping)(ping)(ping)均(jun)(jun)值的(de)(de)(de)(de)(de)最大(da)(da)(da)偏差值與(yu)(yu)三(san)相(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)平(ping)(ping)(ping)均(jun)(jun)值比值。例如，標稱380V三(san)相(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源，在(zai)(zai)壓(ya)(ya)(ya)(ya)(ya)縮(suo)機(ji)(ji)(ji)(ji)接線端測(ce)量(liang)的(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)分(fen)(fen)別為(wei)380V、366V、400V。可(ke)以(yi)計算出(chu)三(san)相(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)平(ping)(ping)(ping)均(jun)(jun)值382V，最大(da)(da)(da)偏差為(wei)20V,所(suo)以(yi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)不(bu)(bu)(bu)平(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)(heng)(heng)百(bai)(bai)分(fen)(fen)數(shu)為(wei)5.2％。作為(wei)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)不(bu)(bu)(bu)平(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)(heng)(heng)的(de)(de)(de)(de)(de)結果(guo)，在(zai)(zai)正(zheng)(zheng)常(chang)運行(xing)使負載電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流的(de)(de)(de)(de)(de)不(bu)(bu)(bu)平(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)(heng)(heng)是電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)不(bu)(bu)(bu)平(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)(heng)(heng)百(bai)(bai)分(fen)(fen)點數(shu)的(de)(de)(de)(de)(de)4－10倍。前(qian)例中，5.2％不(bu)(bu)(bu)平(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)(heng)(heng)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)可(ke)能引起(qi)50％的(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流不(bu)(bu)(bu)平(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)(heng)(heng)。美國(guo)國(guo)家電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)器制造(zao)(zao)(zao)商協會(NEMA)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)動機(ji)(ji)(ji)(ji)和發(fa)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)標準出(chu)版物指出(chu)，由(you)不(bu)(bu)(bu)平(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)(heng)(heng)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)造(zao)(zao)(zao)成(cheng)(cheng)的(de)(de)(de)(de)(de)相(xiang)繞(rao)(rao)組(zu)(zu)(zu)溫升(sheng)百(bai)(bai)分(fen)(fen)比大(da)(da)(da)約是電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)不(bu)(bu)(bu)平(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)(heng)(heng)百(bai)(bai)分(fen)(fen)點數(shu)平(ping)(ping)(ping)方(fang)的(de)(de)(de)(de)(de)兩(liang)倍。前(qian)例中電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)不(bu)(bu)(bu)平(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)(heng)(heng)點數(shu)為(wei)5.2，繞(rao)(rao)組(zu)(zu)(zu)溫度增加的(de)(de)(de)(de)(de)百(bai)(bai)分(fen)(fen)數(shu)為(wei)54％。結果(guo)是一相(xiang)繞(rao)(rao)組(zu)(zu)(zu)過熱(re)(re)而其他兩(liang)個(ge)繞(rao)(rao)組(zu)(zu)(zu)溫度正(zheng)(zheng)常(chang)。一份(fen)由(you)U.L.(保(bao)險商實驗室，美國(guo))完成(cheng)(cheng)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)(dian)(dian)(dian)力公(gong)司允許3％的(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)不(bu)(bu)(bu)平(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)(heng)(heng)，另有30％的(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)力公(gong)司允許5％的(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)不(bu)(bu)(bu)平(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)(heng)(heng)。

六、冷卻不足

功率較(jiao)大(da)的(de)壓(ya)縮機一般都(dou)是回氣冷卻型的(de)。蒸發溫度越低，系統質(zhi)量流(liu)往往越小。

當蒸發溫(wen)度很(hen)低時（超(chao)(chao)過制(zhi)造商的(de)規(gui)定），流量(liang)就不(bu)足以冷(leng)卻電(dian)(dian)機(ji)(ji)(ji)(ji)，電(dian)(dian)機(ji)(ji)(ji)(ji)就會在較高溫(wen)度下運轉。空氣冷(leng)卻型壓(ya)縮機(ji)(ji)(ji)(ji)（一(yi)般(ban)不(bu)超(chao)(chao)過10HP）對(dui)回氣的(de)依賴性(xing)小(xiao)，但對(dui)壓(ya)縮機(ji)(ji)(ji)(ji)環境溫(wen)度和冷(leng)卻風量(liang)有(you)(you)明確要求。制(zhi)冷(leng)劑大量(liang)泄漏也(ye)會造成系統質量(liang)流減小(xiao)，電(dian)(dian)機(ji)(ji)(ji)(ji)的(de)冷(leng)卻也(ye)會受到影響。一(yi)些(xie)無人看管(guan)的(de)冷(leng)庫，往往要等到制(zhi)冷(leng)效果很(hen)差(cha)時才(cai)會發現(xian)制(zhi)冷(leng)劑大量(liang)泄漏了。電(dian)(dian)機(ji)(ji)(ji)(ji)過熱后會出現(xian)頻繁保護(hu)，有(you)(you)些(xie)用戶不(bu)深入(ru)檢查原(yuan)因，甚至將(jiang)熱保護(hu)器短路(lu)，那(nei)是(shi)(shi)非(fei)常(chang)糟糕(gao)的(de)事情。過不(bu)了多久，電(dian)(dian)機(ji)(ji)(ji)(ji)就會燒掉(diao)。壓(ya)縮機(ji)(ji)(ji)(ji)都有(you)(you)安(an)全運行(xing)工(gong)況范圍(wei)。安(an)全工(gong)況主要的(de)考慮因素就是(shi)(shi)壓(ya)縮機(ji)(ji)(ji)(ji)和電(dian)(dian)機(ji)(ji)(ji)(ji)的(de)負荷與冷(leng)卻。由于不(bu)同(tong)溫(wen)區的(de)壓(ya)縮機(ji)(ji)(ji)(ji)的(de)價格不(bu)同(tong)，過去國內冷(leng)凍行(xing)業超(chao)(chao)范圍(wei)使用壓(ya)縮機(ji)(ji)(ji)(ji)是(shi)(shi)比(bi)較常(chang)見的(de)。隨著專業知識的(de)增長和經(jing)濟條件(jian)的(de)改善(shan)，情況已明顯改善(shan)。