定子串电阻启动电动机启动时,在电动机的定子绕组上串联电阻,由于电阻的分压作用,使加在电动机的定子绕组上的电压低于电源电压,待启动后,再将电阻短接,电动机便在额定电压下正常运行。定子绕组串接电阻降压启动控制线路手动控制串联电阻降压启动电路组成分析手动控制串联电阻降压启动合上电源开关QS1,电动机串联电阻降压启动手动控制串联电阻降压启动合上QS2,电阻R被短接,电动机全压正常运转定子串电阻降压起动控制线路4)工作原理5)电路改进从前面分析可知,本线路在起动结束后,KM1、KT一直得电工作。为了减少能量损耗,延长接触器、继电器得使用寿命,要求M起动以后,KM1、KT断电。SB1KM1KM2时间继电器控制串联电阻降压启动FU1FU2KM1KM2FRSB2KM1KM1KM2FRUVWQSKM2RKTKTM3~L1L2L3SB1KM1KM2时间继电器控制串联电阻降压启动FU1FU2KM1KM2FRSB2KM1KM1KM2FRUVWQSKM2RKTKTM3~L1L2L3合上电源开关QSL1L2L3SB1KM1KM2时间继电器控制串联电阻降压启动FU1FU2KM1KM2FRSB2KM1KM1KM2FRUVWQSKM2RKTKTM3~降压启动:按下SB1KM1线圈得电KM1L1L2L3SB1KM1KM2时间继电器控制串联电阻降压启动FU1FU2KM2FRSB2KM1KM1KM2FRUVWQSKM2RKTKTM3~KM1自锁触头闭合,自锁KM1主触头闭合,电动机降压启动KM1动合辅助触头闭合,KT线圈得电KM1L1L2L3SB1KM1KM2时间继电器控制串联电阻降压启动FU1FU2KM2FRSB2KM1KM1KM2FRUVWQSKM2RKTKTM3~松开SB1,继续电动机降压启动KTKM1L1L2L3SB1KM1KM2时间继电器控制串联电阻降压启动FU1FU2KM2FRSB2KM1KM1KM2FRUVWQSKM2RKTM3~KT延时闭合,KM2线圈得电KTKM1L1L2L3SB1KM1KM2时间继电器控制串联电阻降压启动FU1FU2KM2FRSB2KM1KM1KM2FRUVWQSKM2RKTM3~KM2联锁触头断开,对KM1联锁,KM1线圈失电KTKM1L1L2L3SB1KM1KM2时间继电器控制串联电阻降压启动FU1FU2KM2FRSB2KM1KM1KM2FRUVWQSKM2RKTM3~KM2自锁触头闭合,自锁KM2主触头闭合,电阻被短路KTKM1L1L2L3SB1KM1KM2时间继电器控制串联电阻降压启动FU1FU2KM2FRSB2KM1KM1KM2FRUVWQSKM2RKTM3~KM1自锁触头断开,解除自锁KM1主触头断开,电动机全压运行KM1动合辅助触头断开,KT线圈失电,KT延时闭合触头瞬时断开SB1KM1KM2时间继电器控制串联电阻降压启动FU1FU2KM1KM2FRSB2KM1KM1KM2FRUVWQSKM2RKTKTM3~L1L2L3停:按下SB2谢谢观看