If I have two sets of conductors (two unbalanced 120V circuits) in a conduit, can they share a ground wire and if so, is the ground wire sized by the minimum ground wire sizes for the sum of the ungrounded conductor areas?
For example, if I have two 20A circuits (12AWG UF) with both hots and neutrals in the same conduit, can they share a ground wire (10AWG, if my calculations are correct)?
Best Answer
Yes, and no.
The Equipment Ground Conductor for multiple circuits is sized for the largest circuit in the raceway. Sized from table 250.122 for the largest OCPD.
Additionally, the Code allows you to use the raceway, if it is metallic, as the EGC and save your money.
Lastly, if you have UF cable you don't need a raceway unless it is exposed to damage and it should already have an equipment ground wire in the cable.
Good luck with your project!