joshtrevino
Member
- Location
- Beaumont, TX
I am working on a project in which we are upgrading a pipeline metering skid. The scope includes the replacement of several instruments on the skid, addition of supports for piping and cable tray, and the replacement of the control enclosure (new PLC, flow computer, I/O, etc).
We have installed a perimeter grounding grid (ground ring with rods) that we are bonding all supports to as well as the perimeter fencing. The meter skid is isolated from all cathodically protected undergound piping, so there is no need for decoupling on the skid.
My original design was to leave the PLC grounding grid isolated to eliminate any harmonics being transferred to the PLC from the site electrical ground grid. However, now the client is requesting that the PLC ground be tied into the site ground grid simply by bonding to the perimeter ground grid with a #2 bonding jumper.
Does the code address PLC grounding?
Should we look at installing an instrument triad between the PLC ground and the site ground grid? If yes, is this code driven or industry practice?
Any other thoughts/references?
We have installed a perimeter grounding grid (ground ring with rods) that we are bonding all supports to as well as the perimeter fencing. The meter skid is isolated from all cathodically protected undergound piping, so there is no need for decoupling on the skid.
My original design was to leave the PLC grounding grid isolated to eliminate any harmonics being transferred to the PLC from the site electrical ground grid. However, now the client is requesting that the PLC ground be tied into the site ground grid simply by bonding to the perimeter ground grid with a #2 bonding jumper.
Does the code address PLC grounding?
Should we look at installing an instrument triad between the PLC ground and the site ground grid? If yes, is this code driven or industry practice?
Any other thoughts/references?