Common Ground Conductor in Cable Tray

[webermd]

I am running a common ground wires in multiple cable trays coming from a single substation. Each ground wire in each tray is sized for the largest current carrying conductor. The common ground wire will connect from the tray to the ground bus in the MCC.

However, if lets say cables come from two separate MCCs are run in one cable tray with one common ground, which MCC ground bus does that common ground connect to?

Or should there be two separate common grounds run the single cable tray? One from each ground bus in the MCCs that the current carrying conductors originate from?

 

[petersonra]

I am running a common ground wires in multiple cable trays coming from a single substation. Each ground wire in each tray is sized for the largest current carrying conductor. The common ground wire will connect from the tray to the ground bus in the MCC.

However, if lets say cables come from two separate MCCs are run in one cable tray with one common ground, which MCC ground bus does that common ground connect to? Both

Or should there be two separate common grounds run the single cable tray? One from each ground bus in the MCCs that the current carrying conductors originate from? Not required as long as the single EGC is sized properly and connected to both MCC ground buses.

Keep in mind the EGC is used only to open the OCPD in the event of a short circuit.