Ground Wire in Every Conduit?
We are in the process of rough wiring our 180 yr old home. At the suggestion of our Electrical Contractor, we will be installing 2 large juction boxes (1 in the attic and 1 in the basement) and running each 20Amp circuit to one of these 2 boxes. There will then be PVC conduit with THHN/THWN running from the Juction boxes to the Panel. Of course, the junction boxes will be sized appropriately for the number of conductors housed. Our question is if 2 conduits run from a junction box to the panel due to space constraints and allowable fill capacities, do we need a ground in each conduit or just 1 of the conduits?