黄一钫 发表于 2006-10-25 22:04:40

异步电动机绕组损坏的原因及处理方法

<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt; WORD-BREAK: break-all; TEXT-ALIGN: left; mso-pagination: widow-orphan" align=left><SPAN style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-bidi-font-family: 宋体; mso-font-kerning: 0pt">经统计,生产上使用的三相异步电动机,在运行中的故障属绕组烧坏的电气故障约<SPAN lang=EN-US>85%</SPAN>,机构及其他故障约<SPAN lang=EN-US>15%</SPAN>,绕组烧坏的原因多为缺相运行或过载运行、绕组接地及绕组相间或匝间短路。其次是定、转子摩擦、断条等机械方面的原因。这里着重从电气角度分析电机绕组烧损的故障原因,并提出相应的处理方法。<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;</SPAN>一、缺相运行<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;1.&nbsp;</SPAN>故障现象<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;</SPAN>电机不能起动,即使空载能起起动,转速慢慢上升,有嗡嗡声;电机冒烟发热,并伴有烧焦味。<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;2.&nbsp;</SPAN>检查结果<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;</SPAN>拆下电机端盖,可看到绕组端部有<SPAN lang=EN-US>1/3</SPAN>或<SPAN lang=EN-US>2/3</SPAN>的极相绕组或焦或变成深棕色。<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;3.&nbsp;</SPAN>故障原因及处理方法<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;</SPAN>(<SPAN lang=EN-US>1</SPAN>)电动机供电回路熔丝回路接触不良或受机械损伤,致使某相熔丝熔断。<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;</SPAN>(<SPAN lang=EN-US>2</SPAN>)电动机供电回路三相熔丝规格不同,容量小的熔丝烧断。应根据电动机功率大小,更换为规格相同的熔丝。<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;</SPAN>(<SPAN lang=EN-US>3</SPAN>)电动机供电回路中的开关<SPAN lang=EN-US>(</SPAN>隔离开关、胶盖开关等<SPAN lang=EN-US>)</SPAN>及接触器的触头接触不良<SPAN lang=EN-US>(</SPAN>烧伤或松脱<SPAN lang=EN-US>)</SPAN>。修复并调整动、静触头,使之接触良好。<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;</SPAN>(<SPAN lang=EN-US>4</SPAN>)线路某相缺相。查出断线处,并连接牢固。<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;</SPAN>(<SPAN lang=EN-US>5</SPAN>)电动机绕组连线间虚焊,导致接触不良。认真检查电动机绕组连接线并焊牢。<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;</SPAN>二、过载运行<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;1.&nbsp;</SPAN>故障现象<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;</SPAN>电动机电流超过额定值;电动机温升超过额定温升。<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;2.&nbsp;</SPAN>检查结果<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;</SPAN>电机三组绕组全部烧毁;轴承无润滑脂或砂架损坏;定、转子铁心相磨擦,俗称扫膛。<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;3.&nbsp;</SPAN>故障原因及处理方法<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;</SPAN>(<SPAN lang=EN-US>1</SPAN>)负载过重时,要考虑适当减载或更换容量合适的电动机。<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;</SPAN>(<SPAN lang=EN-US>2</SPAN>)电源电压过高或过低,需加装三相电源稳压补偿柜。<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;</SPAN>(<SPAN lang=EN-US>3</SPAN>)电机长期严重受潮或有腐蚀性气体侵蚀,绝缘电阻下降。应根据具体情况,进行大修或更换同容量、同规格的封闭电动机。<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;</SPAN>(<SPAN lang=EN-US>4</SPAN>)轴承缺油、干磨或转子机械不同心,导致电动机转子扫膛,使电动机电流超过额定值。首先应认真检查轴承磨损情况,若不合格需更换新轴承;其次,清洗轴承并注入适量润滑脂。然后检查电动机端盖,若端盖中心孔因磨损致使转子不同心,应对端盖进行处理或更换。<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;</SPAN>(<SPAN lang=EN-US>5</SPAN>)机构传动部分发生故障,致使电动机过载而烧坏电机绕组。检查机械部分存在的故障,采取措施处理解决,使之转动灵活。<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US><BR>&nbsp;</SPAN>三、绕组接地<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;1.&nbsp;</SPAN>故障现象<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;</SPAN>电机空载无法起动;电动机供电回路熔丝熔断或开关跳闸。<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;2.&nbsp;</SPAN>检查结果<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;</SPAN>定子槽口绕组和铁心有烧伤痕迹,并有铜熔点;槽内绕组与铁心击穿;绕组引出线外皮绝缘损坏。<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;3.&nbsp;</SPAN>故障原因及处理方法 <SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;</SPAN>(<SPAN lang=EN-US>1</SPAN>)电动机在修复时,塞入竹楔不注意,使槽口绕组绝缘破坏;竹楔年久老化,绝缘不良。应按电机下线工艺挑选优质竹楔,并做好绝缘处理。下线时注意不要使竹楔划伤导线。<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;</SPAN>(<SPAN lang=EN-US>2</SPAN>)对于长期受潮或在腐蚀性气体中工作的电动机,应更换为封闭型电动机。<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;</SPAN>(<SPAN lang=EN-US>3</SPAN>)开启式电动机因金属或金属切屑进入电动机内使绕组绝缘破坏。对此,应在电机周围加设防护网或防护板。<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;</SPAN>(<SPAN lang=EN-US>4</SPAN>)转子平衡块松动或脱落,刮破电动机绕组绝缘。应将平衡块重新调整好方位并固定住,并处理好绕组破损处。<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;</SPAN>(<SPAN lang=EN-US>5</SPAN>)对于无避雷器或避雷器失效的,应加设避雷器或重新校验避雷器。<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;<BR></SPAN>四、绕组相间短路<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;1.&nbsp;</SPAN>故障现象<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;</SPAN>电机无法起动;电机供电回路熔丝熔断或开关跳闸;电机绕组冒烟,有烧焦味。<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;2.&nbsp;</SPAN>检查结果<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;</SPAN>相间短路部位的多股导线烧断,其周围有铜熔点。<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;3.&nbsp;</SPAN>故障原因及处理方法<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;</SPAN>(<SPAN lang=EN-US>1</SPAN>)对于下线时导线表面绝缘划伤或绕组端部绝缘不好的电动机,应将烧伤的导线挑开,清理后焊好,并包好绝缘压平,下入槽后刷上绝缘漆并烘干。若无法修复时,应按原数据重绕。<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;</SPAN>(<SPAN lang=EN-US>2</SPAN>)绕组间连线及引用线的套管必须与电动机绕组的绝缘等级相适<SPAN lang=EN-US><BR></SPAN>应,连线的绝缘套管应比焊点长<SPAN lang=EN-US>15</SPAN>~<SPAN lang=EN-US>25mm</SPAN>。<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;<BR></SPAN>五、绕组匝间短路<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;1.&nbsp;</SPAN>故障现象<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;</SPAN>电机在运转中冒烟,局部温升过高,并有烧焦味。<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;2.&nbsp;</SPAN>检查结果<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;</SPAN>电动机三相电流不平衡;几匝或一个线圈变成裸线。<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;3.&nbsp;</SPAN>故障原因及处理方法<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;</SPAN>(<SPAN lang=EN-US>1</SPAN>)烧坏几匝或一个线圈时,若槽满率不高,可进行穿绕修理。<SPAN lang=EN-US><BR></SPAN>  <SPAN lang=EN-US>&nbsp;</SPAN>(<SPAN lang=EN-US>2</SPAN>)其余部分参见第<SPAN lang=EN-US>4</SPAN>项处理方法。<SPAN lang=EN-US> <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p></o:p></SPAN></SPAN></P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt; WORD-BREAK: break-all; TEXT-ALIGN: left; mso-pagination: widow-orphan; mso-margin-top-alt: auto; mso-margin-bottom-alt: auto" align=left><SPAN style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-bidi-font-family: 宋体; mso-font-kerning: 0pt">  <SPAN lang=EN-US>&nbsp;</SPAN>及时发现并迅速排除电气设备故障,能够预防事故的发生,确保生产顺利进行。对此,必须按照规定定期检查和维护电气设备,准确判断和处理电气设备的运行故障,减少设备事故损失,保证生产正常进行。<SPAN lang=EN-US><o:p></o:p></SPAN></SPAN></P>

熊巍 发表于 2007-11-12 14:37:07

请问一下缺相会引起匝间和相问短路(少量的)吗?

我的电机修好后,用了一会就坏了,找维修的拆开,有少量的匝间和相问短路,他说是缺相引起的,他不负全责.(我确信没有缺相,就是说不过他)

我是7.5kw三相角接电机

waiterzzx 发表于 2007-11-13 11:21:46

楼主是自己的经验总结吗?

zhouyang 发表于 2008-5-9 06:29:27

回复 2# 熊巍 的帖子

再有这种情况,先修后给钱或是签立书面合同
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