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!

  • get a --sheet metal drill-- and widen the hole
    – Traveler
    Jul 31, 2022 at 21:14
  • @Ruskes yep, that or a hole saw, perfectly code legal. You just have to drill it with the existing knockout in place for the pilot drill. Jul 31, 2022 at 21:30
  • I take it you're coming up into the bottom of the panel? What make and model panel is this anyway? Jul 31, 2022 at 22:44
  • It's GE PowerMark Plus 125 amp: homedepot.com/p/… The hub I asked about is in the question is on the top.
    – cheezhd
    Jul 31, 2022 at 23:02
  • Might start by seeing if there are other outdoor panels (whether sold as "sub" or "main" that have the knockout you need, and otherwise fit your needs, and return this one, to get one of those. What is the largst knockout this panel has on the bottom or side where you'd like to come in?
    – Ecnerwal
    Aug 1, 2022 at 1:58

2 Answers 2


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).


Alternative solution

Get a sheet metal drill, also called step drill, and widen the hole, using the existing one as guide.

They come in different sizes.

step dril

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