Generator Power Inlet Box location

Question

I am installing a 50 amp power inlet box to backfeed my 12000W generator (it has 50amp outlet) into the house main circuit panel (with approved interlock kit..). The inlet box is a GE T050N, that only has punch outs on the bottom, and bottom of sides. https://images.homedepot-static.com/catalog/pdfImages/b5/b535b44c-bc9b-47b8-ae55-7859edf6623d.pdf

See my installation zone in the picture below. I was thinking of putting the inlet box directly below the main panel and run 3/4" PVC conduit down from the main panel and into the lower right side of the inlet box. I've been looking on the web for rules on proximity of the natural gas meter regulator to electrical boxes and couldnt find a consensus. I live in Texas and local municipality has adopted 2018 version of Building code, NEC, etc. Any issues with the proposed location? from what I've read on wire size, I need to use 6/3 UF or #8 THHN in the conduit, sound right?

Thank you for your advice

Answer 1

That plan looks fine and normal. They don't like top entries because real-world, they leak.

I myself prefer a "drip loop" as it were, where I enter the bottom of both boxes, with an LR and LL right next to each other.

You must use something like #8 THWN wires. You can't use NM-B obviously. And you cannot use #6/3 UF-B, because UF-B is thin and wide, and that requires wide conduit... 2" for #6. And that inlet box is absolutely unable to support an opening that large!

Generally for 1 cable in conduit, the conduit's practical ID must be 138% of the width of the cable. With 6/3UF that puts you at about 1.65 inches, too big for 1.5".