Drill Top Plate Attic
One hole hole on the wall above the sub panel to get access to the top plate see where the wires are and get your wire fished into the top or back of the panel depending how its mounted.
Drill top plate attic. If you will need to fish wiring through a wall drill a hole through the wood plate in the attic only. Just don t drop the drill. I ve been reading the irc 2015 and the wording for drilling into top plates isn t clear. And i think you can drill larger holes as long as the joists beams resting on the top plate are directly above the studs.
However this would require one to drill one hole through the top plate in order to get the wire from the desired receptacle location into the attic. Cutting drywall and drilling from below may be the only option if you have to access the attic there. I prefer to stick the drill into the vent and drill up into the attic instead of drilling down from the attic. If one wants to add a new receptacle on the second floor in a finished room with no receptacles the easiest method appears to be doing the wiring in the attic.
If that is the case the top plate is not really supporting any load it is only acting as a horizontal tie and nailer. Now that you know the duct will work drill a hole through the double top plate into the attic. It would help to have a right angle drill and i m surprised you can t rent one. I want to pass some conduit up into the attic space over the room for speaker and network cable.
If you drill carefully at an angle you may be able to make it through the top plate and into the wall space without penetrating the outside wall. And use semi rigid wiring fish tape to pull your wiring down to your outlet location. The framing has been done but i m going to be doing the wiring myself. An alternative is to drop all the way through the wall cavity from another top plate in the attic and into the basement or crawlspace then run over to the wall you want to end up in.
I did this recently to run ethernet cable in an exterior wall. Before drilling go into the attic and find the top plate 2x4 that is right above the vent and make sure there are no wires running directly above it that might get cut by the drill. I ve got a 2nd story home theater room under construction. Alternatively i think the only option you have is to cut out the sheetrock near the ceiling and do the hole.