Mike Krzyzewski is really a famous coach of Dream Team. She has coached north america men's basketball team for some time, that's clinched numerous medals for his country. Following Londonfl jerseys supplyn Olympic was over, Krzyzewski told The Associated Press that this game will be his final one as national coach, a job he's held for seven years. He had left open the possibility of swomen nfl jerseystaying with the team beyond the London Games, when practice on Saturday said these will be his last Olympics.When asked if he was sure, Krzyzewski didn't hesitate before again saying, "yecheap nfl jerseys wholesales," this will be his last game "If we could win it, then it might be three major championships in a row, i always do not know when that has been done because we haven't usually won http://govoriotkrito.bg/libs/nflcn08.htmthe globe championships," Krzyzewski said. "It becomes an enormous thing for the program." Whatever, he's an awesome coach. His achievement are going to be remembered by the country.cheap nfl jerseys
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接触器及中间继电器断电不释放或延时释放的原因和修理方法

2013/11/15 10:09:36点击:
接触器及中间继电器断电不释放或延时释放极易造成设备或人身事故,必须设法消除。
1   形成原因
     (1) 新启用的接触器铁心表面有油或使用一定时间后表面有油腻,铁心表面愈光滑愈易发生。这种现象在天冷的时候要严重一些,可能是油的粘性增加的缘故。
     (2) 触头抗熔焊性差,在起动电动机或线路短路时,大电流使触头焊牢而不能释放,其中以纯银触头较易熔焊。
     (3) 机械性故障,如支架的销子和孔配合过紧,销子受振后不能复位而将支架卡住;胶木支架尺寸不合格,动作中卡住不能释放;镙钉未旋紧,受振动而落入接触器内,或其它外物落入而卡住支架;也有些因产品质量很差,胶木外壳或支架变形造成卡住不能释放。
     (4) 铁心片间的绝缘漆或表面油漆受热后流到表面造成断电后不释放。
2   修理和预防
     (1) 接触器装配时,应将表面防锈油脂擦干净。油不擦干净必然要造成延时释放,一般只是延时的时间较短,看不出来罢了。为了防止生锈,出厂的包装要作相应改进。已经发生延时释放或断电不释放的铁芯,应将表面油腻清除。运行中应防止机器的油漏到电器上去,避免再产生油腻。铁心平面要求平整,但也不宜过光,否则易于造成延时释放。
     (2) 交流接触器的主触头应选用抗熔焊能力强的银基含金,如银铁、银镍等,以减少焊牢不释放现象。
     (3) 制造厂应严格控制零部件的质量,防止因配合不当造成卡住的现象;使用时应防止外物落入接触器内,并须将所有的镙钉旋紧,定期检查,以防落入接触器内造成卡住不释放。
     (4) 铁心片间不需要用绝缘漆,表面的油漆也必须烘干。
        除以述原因外,还存在铁芯在断电后一直不能释放的现象,小铁芯剩磁力并不强,一般的油腻又没有这样大的粘性,遇此情况,使用者应仔细分析,多方查找原因。