changing valve is not allowed to open to start working until 30 seconds after the motor is started
问题描述：
changing valve is not allowed to open to start working until 30 seconds after the motor is started
这句该怎么翻译?
1.改变阀门的时候不允许开启运行,要等30秒马达启动后.
2.开启运行的时候改变阀门是不允许的,要等30秒马达启动后.
哪句对的?
3.改变阀门的时候不允许开启运行，要等马达启动30秒后。
答
Direction changing valve 换向阀
is not allowed to open 不允许打开
30 seconds after the motor is started 电机启动后30秒
整句意思：等电机开启后30秒方可打开换向阀开始工作