What day is it today? [ ]
A. It's Tuesday.
B. It's Friday.
C. It's Thursday.
答案:B
液压系统中的工作机构在短时间停止运动可采用(),以达到节省动力损耗,减少液压系统发热,延长泵的使用寿命的目的。
A.调压回路
B.减压回路
C.卸荷回路
安装变频器时,对电源电缆的绝缘检查有何要求?