Maintenance lead guarantee all maintenace persons use insulate tools.

维修负责人必须让维修人员使用绝缘合格的工具。

I'll ask the Maintenace Department to send someone to change it.

我将告诉维修部派人去换灯泡。

And then the author summarized related requirements and technology measures of maintenace and protection of PLC system.

同时，总结了PLC系统的维护和保护的相关要求及技术措施。