Here is the situation. Subpanel needs to be added. Feeder to sub will be in flexible metal conduit. Main panel completely full. So 2 branch ciruits will be landed in sub panel from main panel to make room for 2 pole breaker for sub feed.
Do the neutrals for these 2 branch circuits need to be run out of the main panel to the neutral bar in the subpanel? I am thinking no because the magnetic field from the branch circuits will be cancelled by the by the sub feeders.
I have seen an entire subpanel added with 12 ciruits and not one neutral was landed on the neutral bar (all were landed in the main panel).