Electrical – Do branch circuits sharing conduit with sub-panel feeder wires require separate grounding

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I have installed a 75 amp sub panel with three #6THHN and a #8 ground from the main.
I need to move two branch circuits from main to sub since I do not have space in the 200amp main for the sub panel breaker.

Is a ground wire required for each branch circuit if they are in the same conduit as the feeders for the sub? One inspector said that each circuit has to have a ground. It seems redundant.

Best Answer

No, one ground wire of sufficient size will do the trick

All the branch circuits in a single cable or conduit can share a single ground wire (and are often forced to when metal conduit is used as a ground path or when a multi-circuit cable is used). This is permitted as a consequence of NEC 250.122(C):

(C) Multiple Circuits. Where a single equipment grounding conductor is run with multiple circuits in the same raceway, cable, or cable tray, it shall be sized for the largest overcurrent device protecting conductors in the raceway, cable, or cable tray. Equipment grounding conductors installed in cable trays shall meet the minimum requirements of 392.10(B)(1)(c).

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