RELANCE 30V4060 交流驱动器
按如下顺序切断电源
（1）每个操作站依次退出实时监控及操作系统后，关闭操作站工控机及显示器电源；
（2）逐个关闭控制站电源箱电源；
（3）关闭各个支路电源开关；
（4）关闭不间断电源（UPS）开关；
（5）关闭总电源开关。
大修期间对DCS系统应进行彻底的维护，内容包括
（1）系统停电检修，包括彻底的灰尘清理，改接线等内容。
（2） 对于在日常巡检，定期巡检中发现而不能及时处理的问题进行集中处理，如系统升级，组态下载等。
（3）系统在检修前应对DCS系统组态进行备份，并对系统运行参数（如PID等）进行上载和备份。
（4）在检修期间更改组态、控制及联锁程序，必须组织工艺、设备、电气和仪表相关负责人共同参与联锁调试，并形成联锁调试记录。
（5）检修期间应检查供电和接地系统是否符合要求。
（6）及时做好大修期间DCS维护记录。
大修期间系统维护步骤
Dust and seal the control cabinet, and replace the cooling fan.
7) Maintenance of recorders, printers, alarm windows, human-machine interface equipment, etc.
8) Eliminate defects that cannot be handled during operation, restore and improve various flags.
9) Hardware device function test, configuration software loading and inspection.
10) Measurement module calibration and on-site equipment maintenance.
11) Protection interlocking test.
12) Inspection and replacement of cables, pipelines and their accessories.
DCS systems often have rich self diagnostic functions. Based on the alarm, the fault point can be directly identified, and the maintenance results can also be verified by eliminating the alarm.
2) Poor contact of communication connectors can cause communication faults. After confirming poor contact of communication connectors, tools can be used to redo the connectors; If the communication line is damaged, it should be replaced in a timely manner.
3) The flashing fault light of a certain card or all data on the card being zero may be due to incorrect configuration information, the card being in a standby state with redundant terminal connection wires not connected, the card itself malfunctioning, or the lack of configuration information in that slot.
Major repair projects
The major overhaul of the DCS system is carried out randomly on the main equipment of the group, and the major overhaul items include the following contents:
1) Conduct a comprehensive inspection of the control equipment and keep records.
2) Copy the configuration of all modules and verify their flags and addresses.
3) Clean the power supply and modules of the control cabinet, and clean the dust-proof filter screen of the panel cabinet.
4) Check and tighten the wiring and fixing screws of the control cabinet.
5) Grounding system inspection, power performance testing, and line insulation testing.