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(xia)簡稱壓縮機(ji)）的故(gu)障(zhang)(zhang)可分為電機(ji)故(gu)障(zhang)(zhang)和(he)機(ji)械(xie)故(gu)障(zhang)(zhang)（包(bao)括曲軸，連桿(gan)，活(huo)塞，閥片(pian)，缸蓋墊等(deng)）。

機(ji)械故障往往使電機(ji)超負(fu)荷運轉甚至堵轉，是電機(ji)損壞的主(zhu)要原因之(zhi)一。

電(dian)機的(de)損(sun)壞(huai)主要表(biao)現為(wei)定子(zi)繞(rao)組絕緣(yuan)層(ceng)破壞(huai)（短(duan)路）和斷(duan)路等(deng)。定子(zi)繞(rao)組損(sun)壞(huai)后(hou)很難及時被(bei)發現，最(zui)終可能導(dao)致(zhi)繞(rao)組燒(shao)(shao)毀。繞(rao)組燒(shao)(shao)毀后(hou)，掩蓋(gai)了(le)一些(xie)導(dao)致(zhi)燒(shao)(shao)毀的(de)現象(xiang)或直接原因(yin)，使(shi)得事后(hou)分析和原因(yin)調查(cha)比較困難。然而，電(dian)機的(de)運轉離(li)不開正常的(de)電(dian)源輸(shu)入(ru)，合理的(de)電(dian)機負(fu)荷，良好(hao)的(de)散熱和繞(rao)組漆包線絕緣(yuan)層(ceng)的(de)保護。

從(cong)這幾方面(mian)入手(shou)，不難發現繞組燒毀(hui)的原因不外乎如下(xia)六種：

(1)異常負荷(he)和(he)堵轉；

(2)金屬(shu)屑引起的繞組短路；

(3)接觸器問題；

(4)電源缺相(xiang)和電壓異常；

(5)冷卻(que)不足(zu)；

(6)用(yong)壓縮機抽(chou)真空。

實際(ji)上，多種因素共同促成的電機損壞更為常見(jian)。

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二、異常負荷和堵轉

電(dian)機負荷(he)包括(kuo)壓縮氣體所需負荷(he)以及克服機械摩(mo)擦所需負荷(he)。

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)(run)滑(hua)油(you)(you)過(guo)熱，潤(run)(run)(run)(run)滑(hua)油(you)(you)焦化(hua)變質，以(yi)及缺(que)油(you)(you)等都(dou)會破(po)壞(huai)正(zheng)常潤(run)(run)(run)(run)滑(hua)，導(dao)致潤(run)(run)(run)(run)滑(hua)失效。回液稀(xi)釋潤(run)(run)(run)(run)滑(hua)油(you)(you)，影響(xiang)摩擦(ca)(ca)面正(zheng)常油(you)(you)膜(mo)的(de)形成(cheng)，甚至(zhi)沖刷掉(diao)原有(you)油(you)(you)膜(mo)，增加摩擦(ca)(ca)和磨損(sun)。壓縮(suo)機過(guo)熱會引起使潤(run)(run)(run)(run)滑(hua)油(you)(you)高溫變稀(xi)甚至(zhi)焦化(hua)，影響(xiang)正(zheng)常油(you)(you)膜(mo)的(de)形成(cheng)。系統(tong)回油(you)(you)不好，壓縮(suo)機缺(que)油(you)(you)，自然無法(fa)維持正(zheng)常潤(run)(run)(run)(run)滑(hua)。曲(qu)軸高速旋轉，連桿活塞等高速運(yun)動，沒有(you)油(you)(you)膜(mo)保護的(de)摩擦(ca)(ca)面會迅速升溫，局部(bu)(bu)高溫使潤(run)(run)(run)(run)滑(hua)油(you)(you)迅速蒸發或焦化(hua)，使該部(bu)(bu)位(wei)潤(run)(run)(run)(run)滑(hua)更加困難(nan)，數秒鐘內可引起局部(bu)(bu)嚴重磨損(sun)。潤(run)(run)(run)(run)滑(hua)失效，局部(bu)(bu)磨損(sun)，使曲(qu)軸轉動需(xu)要更大力矩。

小功率(lv)(lv)壓(ya)(ya)縮(suo)機(ji)(ji)（如冰箱，家(jia)用空調壓(ya)(ya)縮(suo)機(ji)(ji)）由(you)于電(dian)(dian)(dian)機(ji)(ji)扭矩小，潤(run)滑失效后常出現堵(du)轉(zhuan)(zhuan)(zhuan)（電(dian)(dian)(dian)機(ji)(ji)無(wu)法轉(zhuan)(zhuan)(zhuan)動）現象，并進入“堵(du)轉(zhuan)(zhuan)(zhuan)－熱保護－堵(du)轉(zhuan)(zhuan)(zhuan)”死循環，電(dian)(dian)(dian)機(ji)(ji)燒(shao)毀只是(shi)(shi)時間問題。而(er)(er)大功率(lv)(lv)半封閉壓(ya)(ya)縮(suo)機(ji)(ji)電(dian)(dian)(dian)機(ji)(ji)扭矩很大，局部磨損(sun)不(bu)會(hui)(hui)(hui)引(yin)起堵(du)轉(zhuan)(zhuan)(zhuan)，電(dian)(dian)(dian)機(ji)(ji)功率(lv)(lv)會(hui)(hui)(hui)在(zai)一定范(fan)圍內隨負(fu)荷(he)而(er)(er)增大，從而(er)(er)引(yin)起更為嚴(yan)重(zhong)的(de)(de)磨損(sun)，甚至引(yin)起咬缸（活塞卡在(zai)氣(qi)缸內），連桿(gan)斷裂等(deng)嚴(yan)重(zhong)損(sun)壞。堵(du)轉(zhuan)(zhuan)(zhuan)時的(de)(de)電(dian)(dian)(dian)流(liu)(liu)(liu)（堵(du)轉(zhuan)(zhuan)(zhuan)電(dian)(dian)(dian)流(liu)(liu)(liu)）大約是(shi)(shi)正常運(yun)行電(dian)(dian)(dian)流(liu)(liu)(liu)的(de)(de)4－8倍。電(dian)(dian)(dian)機(ji)(ji)啟(qi)動瞬(shun)間，電(dian)(dian)(dian)流(liu)(liu)(liu)的(de)(de)峰值(zhi)可接近或達到(dao)堵(du)轉(zhuan)(zhuan)(zhuan)電(dian)(dian)(dian)流(liu)(liu)(liu)。由(you)于電(dian)(dian)(dian)阻放熱量與(yu)電(dian)(dian)(dian)流(liu)(liu)(liu)的(de)(de)平方成正比(bi)，啟(qi)動和堵(du)轉(zhuan)(zhuan)(zhuan)時的(de)(de)電(dian)(dian)(dian)流(liu)(liu)(liu)會(hui)(hui)(hui)使(shi)繞(rao)(rao)組迅速升溫(wen)。熱保護可以(yi)在(zai)堵(du)轉(zhuan)(zhuan)(zhuan)時保護電(dian)(dian)(dian)極，但一般(ban)不(bu)會(hui)(hui)(hui)有很快(kuai)的(de)(de)響應(ying)，不(bu)能阻止(zhi)頻繁啟(qi)動等(deng)引(yin)起的(de)(de)繞(rao)(rao)組溫(wen)度變化。頻繁啟(qi)動和異常負(fu)荷(he)，使(shi)繞(rao)(rao)組經(jing)受高溫(wen)考(kao)驗(yan)，會(hui)(hui)(hui)降低(di)漆(qi)包線的(de)(de)絕緣性能。此外(wai)，壓(ya)(ya)縮(suo)氣(qi)體所需負(fu)荷(he)也會(hui)(hui)(hui)隨壓(ya)(ya)縮(suo)比(bi)增大和壓(ya)(ya)差增大而(er)(er)增大。

因(yin)此將高(gao)溫壓縮(suo)(suo)機(ji)(ji)用于低溫，或將低溫壓縮(suo)(suo)機(ji)(ji)用于高(gao)溫，都會(hui)影響(xiang)電機(ji)(ji)負荷和散熱(re)，是不合(he)適的，會(hui)縮(suo)(suo)短(duan)電極使用壽命(ming)。繞組(zu)絕緣性(xing)能(neng)變差后(hou)，如(ru)果(guo)有(you)其它(ta)因(yin)素(su)（如(ru)金屬屑構成導電回路，酸性(xing)潤滑(hua)油等(deng)）配合(he)，很容易引起短(duan)路而損壞。

三、金屬屑引起的繞組短路

繞組中夾(jia)雜的金屬屑(xie)是短(duan)路和接地(di)絕緣值低(di)的罪魁(kui)禍首。

壓縮機運(yun)轉(zhuan)(zhuan)時(shi)的(de)(de)(de)正(zheng)常振動(dong)，以(yi)(yi)及(ji)(ji)每次啟動(dong)時(shi)繞組(zu)(zu)受電(dian)磁(ci)力作用(yong)而(er)扭動(dong)，都會(hui)(hui)促使(shi)夾(jia)雜于(yu)繞組(zu)(zu)間(jian)的(de)(de)(de)金屬(shu)(shu)屑(xie)與繞組(zu)(zu)漆(qi)(qi)包(bao)線之(zhi)間(jian)的(de)(de)(de)相對(dui)運(yun)動(dong)和(he)(he)摩擦。棱(leng)角銳利(li)的(de)(de)(de)金屬(shu)(shu)屑(xie)會(hui)(hui)劃傷漆(qi)(qi)包(bao)線絕緣層(ceng)，引起短(duan)路。金屬(shu)(shu)屑(xie)的(de)(de)(de)來源包(bao)括施工時(shi)留下(xia)的(de)(de)(de)銅(tong)管屑(xie)，焊渣，壓(ya)(ya)縮(suo)機(ji)(ji)(ji)內部(bu)磨(mo)損和(he)(he)零部(bu)件損壞（比(bi)如(ru)閥(fa)片(pian)(pian)破碎(sui)）時(shi)掉下(xia)的(de)(de)(de)金屬(shu)(shu)屑(xie)等。對(dui)于(yu)全(quan)封(feng)閉壓(ya)(ya)縮(suo)機(ji)(ji)(ji)（包(bao)括全(quan)封(feng)閉渦旋壓(ya)(ya)縮(suo)機(ji)(ji)(ji)），這些(xie)金屬(shu)(shu)屑(xie)或碎(sui)粒會(hui)(hui)落(luo)在(zai)繞組(zu)(zu)上。對(dui)于(yu)半封(feng)閉壓(ya)(ya)縮(suo)機(ji)(ji)(ji)，有些(xie)顆(ke)粒會(hui)(hui)隨氣(qi)體(ti)和(he)(he)潤滑油在(zai)系(xi)統中流動(dong)，最后由于(yu)磁(ci)性聚集(ji)在(zai)繞組(zu)(zu)中；而(er)有些(xie)金屬(shu)(shu)屑(xie)（比(bi)如(ru)軸承(cheng)磨(mo)損以(yi)(yi)及(ji)(ji)電(dian)機(ji)(ji)(ji)轉(zhuan)(zhuan)子(zi)與定子(zi)磨(mo)損（掃膛(tang)）時(shi)產生的(de)(de)(de)）會(hui)(hui)直接落(luo)在(zai)繞組(zu)(zu)上。繞組(zu)(zu)中聚集(ji)了金屬(shu)(shu)屑(xie)后，發生短(duan)路只是一(yi)個時(shi)間(jian)問(wen)題。需要特別提(ti)請注意的(de)(de)(de)是雙(shuang)(shuang)級(ji)壓(ya)(ya)縮(suo)機(ji)(ji)(ji)。在(zai)雙(shuang)(shuang)級(ji)壓(ya)(ya)縮(suo)機(ji)(ji)(ji)中，回氣(qi)以(yi)(yi)及(ji)(ji)正(zheng)常的(de)(de)(de)回油直接進入(ru)第一(yi)級(ji)（低壓(ya)(ya)級(ji)）氣(qi)缸(gang)，壓(ya)(ya)縮(suo)后經中壓(ya)(ya)管進入(ru)電(dian)機(ji)(ji)(ji)腔冷卻繞組(zu)(zu)，然后和(he)(he)普通單級(ji)壓(ya)(ya)縮(suo)機(ji)(ji)(ji)一(yi)樣(yang)，進入(ru)第二級(ji)（高(gao)壓(ya)(ya)級(ji)氣(qi)缸(gang)）。回氣(qi)中帶(dai)有潤滑油，已經使(shi)壓(ya)(ya)縮(suo)過程如(ru)履薄冰，如(ru)果再有回液(ye)，第一(yi)級(ji)氣(qi)缸(gang)的(de)(de)(de)閥(fa)片(pian)(pian)很容易被打碎(sui)。碎(sui)閥(fa)片(pian)(pian)經中壓(ya)(ya)管后可(ke)進入(ru)繞組(zu)(zu)。因此(ci)，雙(shuang)(shuang)級(ji)壓(ya)(ya)縮(suo)機(ji)(ji)(ji)比(bi)單級(ji)壓(ya)(ya)縮(suo)機(ji)(ji)(ji)更容易出現金屬(shu)(shu)屑(xie)引起的(de)(de)(de)電(dian)機(ji)(ji)(ji)短(duan)路。

不幸的(de)事情往(wang)往(wang)湊到一塊，出問題(ti)的(de)壓縮機在開機分(fen)析時聞道的(de)常常是(shi)潤(run)滑(hua)油(you)的(de)焦糊味。金屬面(mian)嚴重磨損時溫度是(shi)很高的(de)，而潤(run)滑(hua)油(you)在175?C以上(shang)時開始(shi)焦化。系統中如果(guo)有較多(duo)水分(fen)（真空抽得不理想，潤(run)滑(hua)油(you)和(he)(he)制冷劑(ji)含水量大，負壓回(hui)氣管破(po)裂(lie)后(hou)空氣進入(ru)等），潤(run)滑(hua)油(you)就可能(neng)出現酸(suan)(suan)性。酸(suan)(suan)性潤(run)滑(hua)油(you)會(hui)(hui)腐蝕(shi)銅管和(he)(he)繞組絕(jue)(jue)緣層，一方面(mian)，它(ta)會(hui)(hui)引起鍍銅現象；另一方面(mian)，這種(zhong)含有銅原子(zi)的(de)酸(suan)(suan)性潤(run)滑(hua)油(you)的(de)絕(jue)(jue)緣性能(neng)很差，為繞組短路提供(gong)了條件。

四、接觸器問題

接觸(chu)器是電(dian)機控(kong)制回路中重要部件之(zhi)一，選型不合理可以毀壞最好的(de)壓縮機。

按負(fu)載(zai)正確選擇接(jie)觸(chu)器(qi)(qi)是極其重要的(de)(de)。接(jie)觸(chu)器(qi)(qi)必須(xu)(xu)能滿足苛刻(ke)的(de)(de)條件，如快(kuai)速循環，持續超載(zai)和(he)低電(dian)(dian)壓。它們必須(xu)(xu)有足夠大(da)的(de)(de)面積(ji)以散發負(fu)載(zai)電(dian)(dian)流所產生(sheng)的(de)(de)熱量，觸(chu)點材料的(de)(de)選擇必須(xu)(xu)在啟動或(huo)堵轉等大(da)電(dian)(dian)流情況下能防止(zhi)焊合。為了安(an)全可靠，壓縮機(ji)接(jie)觸(chu)器(qi)(qi)要同(tong)時斷開(kai)三相電(dian)(dian)路。谷(gu)輪(lun)公司不推薦(jian)斷開(kai)二相電(dian)(dian)路的(de)(de)方(fang)法。在美國，谷(gu)輪(lun)公司認(ren)可的(de)(de)接(jie)觸(chu)器(qi)(qi)必須(xu)(xu)滿足如下四項：

接(jie)觸器必須滿(man)足(zu)ARI標(biao)準780-78“專用接(jie)觸器標(biao)準”規定的工作和測(ce)試準則。

制(zhi)造商必(bi)須保證(zheng)接觸器在室溫下(xia)，在最低銘牌電壓的(de)80％時能閉合。

當使(shi)用單個接(jie)觸器時(shi)(shi)，接(jie)觸器額定電(dian)流必(bi)(bi)須(xu)大于電(dian)機(ji)(ji)銘(ming)牌電(dian)流額定值(RLA).同(tong)時(shi)(shi)，接(jie)觸器必(bi)(bi)須(xu)能承受電(dian)機(ji)(ji)堵轉電(dian)流。如(ru)果接(jie)觸器下游還有其它負載，比如(ru)電(dian)機(ji)(ji)風扇(shan)等，也必(bi)(bi)須(xu)考(kao)慮。

當使用兩個接觸器(qi)時，每個接觸器(qi)的(de)分繞(rao)組堵轉(zhuan)額定(ding)值必須等(deng)于(yu)或大(da)于(yu)壓縮機(ji)半繞(rao)組堵轉(zhuan)額定(ding)值。

接觸器的(de)額定電(dian)流(liu)不(bu)能(neng)低于壓縮機銘牌上(shang)的(de)額定電(dian)流(liu)。

規格小或(huo)質量低(di)劣的(de)(de)(de)接觸(chu)器無法經受壓縮機(ji)(ji)(ji)啟(qi)動(dong)，堵轉和低(di)電(dian)壓時的(de)(de)(de)大(da)電(dian)流(liu)沖擊，容(rong)易出(chu)現(xian)(xian)單(dan)相或(huo)多相觸(chu)點抖(dou)(dou)(dou)動(dong),焊接甚(shen)至脫落的(de)(de)(de)現(xian)(xian)象，引起(qi)電(dian)機(ji)(ji)(ji)損壞。觸(chu)點抖(dou)(dou)(dou)動(dong)的(de)(de)(de)接觸(chu)器頻繁地啟(qi)停電(dian)機(ji)(ji)(ji)。電(dian)機(ji)(ji)(ji)頻繁啟(qi)動(dong)，巨大(da)的(de)(de)(de)啟(qi)動(dong)電(dian)流(liu)和發熱(re),會(hui)加劇繞(rao)組絕(jue)(jue)緣層的(de)(de)(de)老(lao)化。每次啟(qi)動(dong)時，磁(ci)性(xing)力(li)矩(ju)使(shi)電(dian)機(ji)(ji)(ji)繞(rao)組有微小的(de)(de)(de)移動(dong)和相互摩(mo)擦。如果(guo)有其它因素(su)配合（如金屬屑(xie)，絕(jue)(jue)緣性(xing)差的(de)(de)(de)潤(run)滑油(you)等），很容(rong)易引起(qi)繞(rao)組間(jian)短路。熱(re)保護(hu)系(xi)統并未設計成能(neng)防(fang)止(zhi)這種毀壞。此外，抖(dou)(dou)(dou)動(dong)的(de)(de)(de)接觸(chu)器線圈容(rong)易失效。如果(guo)有接觸(chu)線圈損壞，容(rong)易出(chu)現(xian)(xian)單(dan)相狀態。

如(ru)果接(jie)觸(chu)(chu)器(qi)選型偏小，觸(chu)(chu)頭不(bu)能承受電(dian)弧和由(you)于(yu)頻繁開(kai)停循環或不(bu)穩定控(kong)(kong)制回(hui)(hui)路電(dian)壓(ya)產(chan)生(sheng)的高溫，可能焊(han)合(he)或從觸(chu)(chu)頭架中脫落。焊(han)合(he)的觸(chu)(chu)頭將產(chan)生(sheng)永(yong)久性單相狀(zhuang)態，使(shi)過載保護器(qi)持(chi)續(xu)地循環接(jie)通和斷開(kai)，需要特別強調的是，接(jie)觸(chu)(chu)器(qi)觸(chu)(chu)點焊(han)合(he)后，依賴接(jie)觸(chu)(chu)器(qi)斷開(kai)壓(ya)縮機電(dian)源回(hui)(hui)路的所有控(kong)(kong)制（比如(ru)高低壓(ya)控(kong)(kong)制，油(you)壓(ya)控(kong)(kong)制，融霜(shuang)控(kong)(kong)制等(deng)）將全部(bu)失效(xiao)，壓(ya)縮機處于(yu)無保護狀(zhuang)態。

因此，當電(dian)機燒毀(hui)后(hou)，檢查接觸器是必(bi)不可少的工序。接觸器是導致電(dian)機損壞(huai)的一(yi)個常常被(bei)人(ren)遺(yi)忘(wang)的重要原因。

五、電源缺相和電壓異常

電壓不正常和缺相可以輕而(er)易(yi)舉地毀掉任何電機。

電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)變化范圍(wei)不(bu)(bu)能(neng)超過(guo)額定(ding)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)的(de)(de)(de)(de)±10%。三相(xiang)間的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)不(bu)(bu)平(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)(heng)不(bu)(bu)能(neng)超過(guo)5％。大(da)(da)功率電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)(ji)必須獨立供電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，以(yi)防同(tong)線(xian)其他大(da)(da)功率設備啟動(dong)和(he)運轉(zhuan)時造(zao)成(cheng)低(di)電(dian)(dian)(dian)(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)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)(ji)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)線(xian)必須能(neng)夠(gou)承載電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)(ji)的(de)(de)(de)(de)額定(ding)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流。如果(guo)發生缺相(xiang)時壓(ya)(ya)(ya)(ya)(ya)縮(suo)(suo)機(ji)(ji)(ji)(ji)(ji)正(zheng)在(zai)(zai)運轉(zhuan)，它將繼續運行但(dan)會(hui)(hui)有大(da)(da)的(de)(de)(de)(de)負載電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流。電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)(ji)繞(rao)組(zu)(zu)會(hui)(hui)很快過(guo)熱，正(zheng)常(chang)情況下壓(ya)(ya)(ya)(ya)(ya)縮(suo)(suo)機(ji)(ji)(ji)(ji)(ji)會(hui)(hui)被熱保(bao)護(hu)。當電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)(ji)繞(rao)組(zu)(zu)冷(leng)卻至設定(ding)溫(wen)(wen)度，接(jie)觸器(qi)會(hui)(hui)閉(bi)合(he)，但(dan)壓(ya)(ya)(ya)(ya)(ya)縮(suo)(suo)機(ji)(ji)(ji)(ji)(ji)啟動(dong)不(bu)(bu)起來，出(chu)現堵轉(zhuan)，并(bing)進入“堵轉(zhuan)－熱保(bao)護(hu)－堵轉(zhuan)”死循(xun)環(huan)。現代電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)(ji)繞(rao)組(zu)(zu)的(de)(de)(de)(de)差(cha)(cha)別(bie)非常(chang)小，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)三相(xiang)平(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)(heng)時相(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流的(de)(de)(de)(de)差(cha)(cha)別(bie)可(ke)以(yi)忽略。理想(xiang)狀態(tai)下，相(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)始終相(xiang)等，只要(yao)在(zai)(zai)任一(yi)(yi)相(xiang)上接(jie)一(yi)(yi)個保(bao)護(hu)器(qi)就可(ke)以(yi)防止過(guo)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流造(zao)成(cheng)的(de)(de)(de)(de)損(sun)壞。實際上很難保(bao)證相(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)的(de)(de)(de)(de)平(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)(heng)。電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)不(bu)(bu)平(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)(heng)百(bai)分(fen)(fen)數計算方(fang)法(fa)為(wei)，相(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)與(yu)三相(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)平(ping)(ping)(ping)均值(zhi)的(de)(de)(de)(de)最(zui)大(da)(da)偏差(cha)(cha)值(zhi)與(yu)三相(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)平(ping)(ping)(ping)均值(zhi)比(bi)值(zhi)。例如，標稱380V三相(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)，在(zai)(zai)壓(ya)(ya)(ya)(ya)(ya)縮(suo)(suo)機(ji)(ji)(ji)(ji)(ji)接(jie)線(xian)端測量的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)分(fen)(fen)別(bie)為(wei)380V、366V、400V。可(ke)以(yi)計算出(chu)三相(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)平(ping)(ping)(ping)均值(zhi)382V，最(zui)大(da)(da)偏差(cha)(cha)為(wei)20V,所以(yi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)不(bu)(bu)平(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)(heng)百(bai)分(fen)(fen)數為(wei)5.2％。作為(wei)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)不(bu)(bu)平(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)(heng)的(de)(de)(de)(de)結(jie)果(guo)，在(zai)(zai)正(zheng)常(chang)運行使負載電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流的(de)(de)(de)(de)不(bu)(bu)平(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)(heng)是(shi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)不(bu)(bu)平(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)(heng)百(bai)分(fen)(fen)點(dian)數的(de)(de)(de)(de)4－10倍。前例中(zhong)，5.2％不(bu)(bu)平(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)(heng)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)可(ke)能(neng)引起50％的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流不(bu)(bu)平(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)(heng)。美(mei)國(guo)國(guo)家(jia)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)器(qi)制造(zao)商(shang)協會(hui)(hui)(NEMA)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)機(ji)(ji)(ji)(ji)(ji)和(he)發電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)(ji)標準出(chu)版物指出(chu)，由不(bu)(bu)平(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)(heng)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)造(zao)成(cheng)的(de)(de)(de)(de)相(xiang)繞(rao)組(zu)(zu)溫(wen)(wen)升百(bai)分(fen)(fen)比(bi)大(da)(da)約是(shi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)不(bu)(bu)平(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)(heng)百(bai)分(fen)(fen)點(dian)數平(ping)(ping)(ping)方(fang)的(de)(de)(de)(de)兩倍。前例中(zhong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)不(bu)(bu)平(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)(heng)點(dian)數為(wei)5.2，繞(rao)組(zu)(zu)溫(wen)(wen)度增加的(de)(de)(de)(de)百(bai)分(fen)(fen)數為(wei)54％。結(jie)果(guo)是(shi)一(yi)(yi)相(xiang)繞(rao)組(zu)(zu)過(guo)熱而其他兩個繞(rao)組(zu)(zu)溫(wen)(wen)度正(zheng)常(chang)。一(yi)(yi)份由U.L.(保(bao)險(xian)商(shang)實驗室，美(mei)國(guo))完成(cheng)的(de)(de)(de)(de)調查顯示，43％的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)力公司允(yun)許3％的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)不(bu)(bu)平(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)(heng)，另有30％的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)力公司允(yun)許5％的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)不(bu)(bu)平(ping)(ping)(ping)衡(heng)(heng)(heng)(heng)(heng)。

六、冷卻不足

功率較大的壓縮機一般都(dou)是回(hui)氣冷卻型的。蒸發溫度越低(di)，系(xi)統質量流往往越小。

當(dang)蒸發溫(wen)度很(hen)低時（超過(guo)制(zhi)造(zao)商的(de)(de)規定），流量就不(bu)(bu)足以冷(leng)(leng)(leng)卻(que)(que)電(dian)機(ji)(ji)，電(dian)機(ji)(ji)就會(hui)在較高溫(wen)度下運轉。空(kong)氣冷(leng)(leng)(leng)卻(que)(que)型(xing)壓(ya)(ya)縮(suo)(suo)機(ji)(ji)（一(yi)般不(bu)(bu)超過(guo)10HP）對回氣的(de)(de)依賴性小(xiao)，但(dan)對壓(ya)(ya)縮(suo)(suo)機(ji)(ji)環境溫(wen)度和冷(leng)(leng)(leng)卻(que)(que)風量有(you)明確要(yao)求。制(zhi)冷(leng)(leng)(leng)劑大(da)量泄漏也(ye)會(hui)造(zao)成系(xi)統質(zhi)量流減小(xiao)，電(dian)機(ji)(ji)的(de)(de)冷(leng)(leng)(leng)卻(que)(que)也(ye)會(hui)受到(dao)影響。一(yi)些(xie)無(wu)人看管的(de)(de)冷(leng)(leng)(leng)庫，往(wang)往(wang)要(yao)等到(dao)制(zhi)冷(leng)(leng)(leng)效果很(hen)差時才會(hui)發現(xian)制(zhi)冷(leng)(leng)(leng)劑大(da)量泄漏了。電(dian)機(ji)(ji)過(guo)熱后會(hui)出現(xian)頻繁(fan)保護，有(you)些(xie)用(yong)戶不(bu)(bu)深入檢(jian)查原因(yin)，甚至將熱保護器短路，那是非常糟(zao)糕的(de)(de)事情(qing)(qing)。過(guo)不(bu)(bu)了多久，電(dian)機(ji)(ji)就會(hui)燒掉。壓(ya)(ya)縮(suo)(suo)機(ji)(ji)都有(you)安全運行工況(kuang)(kuang)范(fan)(fan)圍(wei)(wei)。安全工況(kuang)(kuang)主要(yao)的(de)(de)考(kao)慮因(yin)素(su)就是壓(ya)(ya)縮(suo)(suo)機(ji)(ji)和電(dian)機(ji)(ji)的(de)(de)負(fu)荷與冷(leng)(leng)(leng)卻(que)(que)。由于不(bu)(bu)同(tong)溫(wen)區(qu)的(de)(de)壓(ya)(ya)縮(suo)(suo)機(ji)(ji)的(de)(de)價格不(bu)(bu)同(tong)，過(guo)去國內冷(leng)(leng)(leng)凍(dong)行業(ye)超范(fan)(fan)圍(wei)(wei)使用(yong)壓(ya)(ya)縮(suo)(suo)機(ji)(ji)是比較常見的(de)(de)。隨著專(zhuan)業(ye)知識的(de)(de)增長(chang)和經(jing)濟條件的(de)(de)改(gai)善，情(qing)(qing)況(kuang)(kuang)已明顯(xian)改(gai)善。