I am working on a fuel farm automation project of Airport. We have supplied DCS system. I came to know after visiting site that there is no separate earth pits are available for instrument system. All the earthing system including lightning are connected to a single grid. I am using IS, Non IS and FF devices and have separate busbars for each in the DCS panel. Since a common grid is there, I am getting continuity between all. Now the construction work at site is already completed. Is there any way I can make sure safety of my system and instruments and provide isolation??
Thanks in advance