the ground conductor for the sub panel back to the main panel connection should be in the same conduit/cable as the two hots and the neutral. This is the only ground that is needed on a sub panel unless the panel is located in another structure. In that case a ground rod may be required as well. Contrary to popular belief, ground rods will not clear a fault in the case of an electrical malfunction. The rod is only there to protect the system in the event of a high energy event such as a lightning strike. The ground wire back to the main panel will carry any fault current back to the source/zero reference connection point which is what will clear a fault.
Proper grounding and requirements for inground pool with paver patio
- Thread starter steveg_nh
- Start date
That is the situation I have. My sub panel is in a separate garage building and therefore has its own ground rod as well as a ground wire run back to the main house panel. I suspect steveg_nh has a similar installation. That would explain the additional ground rod. Thanks danpik for the great explaination.
Agreed, great explanation. And yes, my sub panel has a ground that is in the same conduit as the two hots and the neutral, back to the main panel. While my panel isn't in another building, it is outside, freestanding, mounted on a backer mounted to 4x4 posts. So it's not "in" the same building as the main panel, it's outside and not even mounted on the house itself. Here's a pic from the install last fall:
