So I am coming out of my subpanel with 1/2 in metal conduit and using metal handy boxes with NEMA 5-20 for all the receptacles on my two indoor branch circuits. One is dedicated for a window unit AC. All wires are 12AWG stranded copper THHN/THWN.
The ac receptacle is protected with AFCI and GFCI because part of the unit is outdoors. The other receptacles are protected with AFCI only.
So six conductors in all come out. At a t-type conduit body we split off L1/N/G and go up to a handy box near the window. L2/N/G continue on to the wall receptacles.
A separate N ang G run to each circuit. I chose to use a separate G for the two circuits in case the G to one circuit somehow comes loose. No splices are planned anywhere in this setup. All receptacles use the better clamp-type screw connectors the hold the wire captive between two plates.
Is this safe? Am I violating the fill calculation for the conduit body? I used an online calculator assuming 6 conductors pass thru box, and it yielded 13.5 cubic inches ... really? Is that much room really needed with no splices?