DCS and instruments

Generally, it is the instrument installation workers who do the wiring. However, as for who does a good job at wiring it, of course it’s the person who will be responsible for maintaining it that does so

This post was last edited by lotos1987 on 2015-12-10 22:03. There are local terminal boards and wiring on the instrument side; the DCS has its own terminal blocks or intermediate cabinets, and the entire plant is equipped with a cable network. The instrument installers are only responsible for the instrument itself up to the local terminal board ； The DCS side, together with the entire plant’s cable network, is handed over to a reliable construction contractor. The cooperation between the two parties is carried out through standard termination documents, and the format and representation method of these documents must be standardized by the design institute.

The instrument cabinets are equipped with \"field signal terminal blocks,\" to which all external signal cables are connected. This is the task of the construction team, and their work ends here; the interior part falls within the scope of integration provided by the DCS manufacturer. Because instruments generally use multiple pairs of main cables. Installing this terminal block facilitates internal wire miswiring (connecting to different terminal boards in the system), or it allows the use of jumper wires from the terminal block, offering flexibility. Although the terminal block takes up some space, we consider it practical and convenient for maintenance. There will be no disputes over design or construction, so the concerns raised by the original poster do not apply. I guess you’re not too comfortable letting the construction team connect wires to the system’s terminal boards, safety barriers, relay bases, and secondary meters. . . We have also gone through this process. @jiaguoyun

We are the instrument maintenance staff connecting the wires, so as to become familiar with them and facilitate future maintenance.

I think it’s whoever takes care of it that will handle it, after all, once the task is taken on, they’ll become familiar with it when it comes to maintenance

Large DCS systems are the responsibility of the installation company; starting from the safety barriers, through the internal wires to the terminal blocks in the cabinets, these terminal blocks are connected to the on-site intermediate junction boxes via main cables, and from there to the measuring instruments. For smaller systems, generally the manufacturer will fabricate the cabinet terminal blocks for you, and then the installation company can directly connect the cables on-site. Typically, instrument technicians are only responsible for wiring and calibration. Not responsible for wiring.

If it’s the instrument that’s responsible for maintenance, then it’s definitely the instrument that’s connected. I can clearly see all the connections I made myself.