bluenoser337
Member
I am working on an outdoor PLC panel that is having issues with damaged PLC modules among other things. The first thing I noticed is that the panel has no incoming service ground wire. In most panels I've worked with in the past, the site ground ran right into the control panel to a common bus (after connecting to the neutral in the service disconnect) and all grounding/bonding wires were connected directly to that bus. The attached sketch shows the layout. Here are some details. (A) 3-phase power with neutral runs to disconnect where neutral and ground wires are connected. 3 phases and neutral continue to meter and then into panel. Ground wire ends at the disconnect. Control panel ground is through the rigid steel conduit connections only. (B) "Grounding" wires in the PLC panel are connected anywhere and everywhere to the backplate. Comments, please from a code point-of-view and from a "sensitive equipment protection" point-of-view. Many thanks!!