Ground wire(s) in multiple conduits between sub panel and j-box

masterofnone · Jul 4, 2023

At long last my wife is getting her new kitchen and the contractor will be running 10 or so new circuits from a new sub panel. The sub panel, unfortunately, is on an outside wall around 35 feet from the kitchen. The wiring will have to go down the wall, into the crawlspace under the house, and over closer to the kitchen area.

I haven't been able to speak with the contractor's electrician yet. Is it reasonable to think the electrician may decide to run the multiple circuits--correctly derated and upsized as necessary--in 2 or 3 conduits from the sub panel to a junction box near the kitchen area, with the individual circuits branching out from there? And in this case would each branch circuit have its ground wire connected at the junction box, not all the way back at the sub panel?

If so, my question is: should each of the conduits contain an appropriately sized ground wire to the sub panel, or is just a single ground wire allowed, based on the highest-amperage circuit. I googled but was unable to find a specific answer.

I know I may be missing other ways this wiring may be done. I'm willing to be enlightened.

Megawatt · Jul 4, 2023

masterofnone said:
At long last my wife is getting her new kitchen and the contractor will be running 10 or so new circuits from a new sub panel. The sub panel, unfortunately, is on an outside wall around 35 feet from the kitchen. The wiring will have to go down the wall, into the crawlspace under the house, and over closer to the kitchen area.

I haven't been able to speak with the contractor's electrician yet. Is it reasonable to think the electrician may decide to run the multiple circuits--correctly derated and upsized as necessary--in 2 or 3 conduits from the sub panel to a junction box near the kitchen area, with the individual circuits branching out from there? And in this case would each branch circuit have its ground wire connected at the junction box, not all the way back at the sub panel?

If so, my question is: should each of the conduits contain an appropriately sized ground wire to the sub panel, or is just a single ground wire allowed, based on the highest-amperage circuit. I googled but was unable to find a specific answer.

I know I may be missing other ways this wiring may be done. I'm willing to be enlightened.

I’m a little confused but most electrical companies will probably pull romex cables to each dedicated circuits, so about 10 separate cables. All grounds should be connected at the panel and the loads. Maybe if you requested the circuits be in conduit then that’s a different story. In my opinion all circuits should have their own ground wires that are installed in multiple circuits conduit. If it’s a metal junction box then you’re required to ground it too. Hope this helps