I am installing an outdoor subpanel and struggling to figure out the proper way to connect the feeder to the panel. I am planning to run 2,2,2,6 conductors in 1 1/4 PVC. The subpanel doesn't have any knockouts large enough for that sized conduit, and I don't have access to a knockout punch. So I think that leaves attaching through the hub on top. I've found a hub cover with a 1 1/4 sized hole, but the hole is threaded metal. I'm wondering what the proper, code-approved way to transition the PVC conduit to the metal threaded hub is? I believe the best thing to do is a threaded metal nipple to a female PVC adapter, but I've also seen some suggestions that this isn't always code acceptable. Alternatively, if anyone has suggestions for inexpensive ways to add a 1 3/4 knockout for the 1 1/4 conduit, I'd appreciate that too. Many thanks!
You're doing the thing we say never to do...
... and paying the price already.
We have so many people come through here saying "help, my panel is full" that we say "When buying panels, think BIG and get a really large panel with plenty of spaces. Spaces are cheap, so there's no earthly reason to run out of them".
Later when are at a project impasse because you are out of spaces, trust us - you will not remember the taste of the pizza you bought with the paltry savings. Spaces are cheap.
This is fate agreeing with us.
In this case your size R2A box has no openings larger than 3/4". They did not imagine feeder entering any way other than the top. So keeping that box will wipe out your cost savings by forcing you to buy special tools.
A 12-space panel - a modest upgrade - will use the R3 or R4 box which has no less than six 1-1/4" openings. (most concentric to 2" openings, actually).