[billfred]

I’m running 6/3 romex from my breaker box inside the house through the studs and then exiting to the outside to tie into a spa disconnect box.
Can I have the romex come straight out of the wall and tie into the back of the disconnect box on the exterior wall?

 

[surferdude2]

If you are landing it in a weatherproof box, it is normally allowed. You are not allowed to extend it from there.

 

[seharper]

If you are landing it in a weatherproof box, it is normally allowed. You are not allowed to extend it from there.

NOT doubting you. But I'd love to see the code cite on that one. It comes up all the time and I'd like to have something to rely on!

 

[seharper]

Also posted here.

 

[surferdude2]

It can be justified by common sense, specific to a particular situation, to the point where an inspector will normally accept it. It can never be technically legitimized to the point of being absolutely code compliant down to that last 1/4" of NM that is required in the box. Silly technicality, what?

E.g., If you could easily have created a junction inside the building, it might not be accepted. You shouldn't even try it in that case. If however, it was practically impossible to create an indoor junction, it will likely be viewed by an inspector as within his authority to allow. However, if you didn't land it in a weatherproof OR waterproof box, it would likely be shot down, even if there was a roof over the area.

It's a low risk gamble with good odds favoring a common sense approach.

Edit, I'm not saying an inspector on NEW construction, with open walls, will let you run NM to the exterior under any circumstances. Most won't... you should use the proper cable (or conduit/wire) from the last junction or source. That means I wouldn't advise the OP to try it... he is making a new run from the panel... use UF or conduit with thhn/thwn wire.

 

[Old Thomas]

My reading of the NEC leads me to believe it is a violation. It says NM cable cannot be used in a wet location and it says an outdoor weatherproof box is a wet location (damp location if on a porch or similarly protected from direct rain). I am not aware of an exception. That said, it is always done to outside boxes and lights where the wire goes directly through the wall and into the box and I have never seen it cited as a violation in my 50 years around construction.

 

[surferdude2]

Glaring examples would be the millions of residential exterior weather tight main panels... filled with NM entries. :devil3:

I say if the NM isn't exposed to the elements, it's allowed to land in a weatherproof box... no further exterior extensions to NM allowed.

 

[Sparkyb60]

I'm wondering if the #10 ground in the 6/3 Romex is large enough ? What size ground is needed according to the spa instructions ?

 

[Jim Port]

The inside of the box is not a wet area. Never seen an NM into the back of the box cited as a violation.

 

[chandler48]

I take outside box installations one step further by applying silicone on the top and two sides of the box to prevent water infiltration.

 

[Old Thomas]

The inside of the box is not a wet area. Never seen an NM into the back of the box cited as a violation.

I went back and studied the NEC and I agree, contrary to my previous post. The NEC says the inside of buried boxes and raceways are wet locations as are the interiors of above grade raceways. It does not mention the interior of boxes located in damp or wet locations. If they wanted it, they would have printed it. I stand corrected.