I need to provide an underground path for service wire from a transformer to a meter base for 200A service. This is in WA state. I'm looking at a semi-flush mount box.

I know how to connect the conduit to the underside of a surface mount box. How would I do this for a flush or semi-flush mount box? Looking at page 3 of the data sheet, it appears the connection for the underground service is about in the middle of the attachment flange.

Would I use something like this offset meter connector? It seems like that would make it challenging to install plywood on the outside studs and then whatever siding material I choose.

If anyone has pictures illustrating connecting to a box like this, I'd appreciate it.

  • Shouldn't connection from transformer to your meter be the power company's responsibility?
    – keshlam
    Feb 10, 2023 at 20:23
  • They run the wire, but I believe they expect me to provide the conduit - still checking. Even if what you say is the case, I'd love a picture showing what this would end up looking like. Feb 10, 2023 at 20:42
  • Why do you want to use a recessed box? They're for situations where the service comes in inside the wall. Save yourself some hassle and go with a conventional surface-mount box.
    – isherwood
    Feb 10, 2023 at 20:45
  • This picture shows who owns what, which is consistent with what I've seen elsewhee: pennaelectric.com/understanding-home-electrical-panel-basics Feb 10, 2023 at 20:46
  • aesthetics. I understand how to do a surface mounted box, but since there are many semi-flush boxes on the market, there must be a good way to install them. Feb 10, 2023 at 20:47

1 Answer 1


The semi-flush box is by design, "half in and half out" of the wall. As such, it will have provision for the box entry - expecting you to either come up external to the box or bring the conduit up inside the walls and foundation (cast in place). Yours is clearly the latter, with the conduit entry being on the "in-the-wall" side of the wall boundary.

If the box's design is not compatible with what is achievable at your site, then NEC 110.3(B) "Use according to labeling and instructions" applies in full force, and it is not the correct enclosure for your application. I would not attempt to freestyle a connection scheme as that would hurt weather protection for your building. I agree it seems rather awkward to route on an existing home. I think it's intended for new builds.

The drawing looks odd, like it's been "flopped". I think they provide no knockouts on the "outside of the wall" side, except for a few 1/2" or 3/4" knockouts for electrician's receptacle and that kind of thing. I would ask at the store and see if they'll let you crack a box open and see for yourself.

  • Thanks for that. This is new construction, so if it calls for having the conduit imbedded in the foundation, that's doable. I'll check into that. No store nearby has the product. I'll call Schneider on Mon and ask them. Feb 10, 2023 at 23:35

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