Can a combiner box be installed horizontally?

[dkistner1111]

I am building Brad Cagle's mobile solar ground mount, and I'm wondering if I could mount the six-string solar combiner box lying flat instead of upright so it could be attached to the mobile frame underneath the array. My box is supposedly waterproof, and the frame of the mount will be on 5-inch casters over grass. This mobile mount with 800 watts of panels will sit beside a fixed ground-mounted two-panel 400-watt array and both arrays will be hooked to the combiner box. I'd like to be able to add another 800-watt array on another mobile mount at some future point and am thinking the mount with the combiner box could sit between the two other arrays. I am renting, so I cannot mount it to the house. The alternative would be to put the combiner box on a t-post near the arrays or mount it underneath the fixed panels. Thoughts?

 

[timselectric]

My OCD wouldn't allow me to mount it sideways. lol
But as long as it's still rated as water proof in that orientation, then you can.

 

[Symbioquine]

TL;DR; reputable manufacturers should list the acceptable mounting orientations for a given water resistance rating.

There's a good chance it's a NEMA 3R (refers to the kind of water resistance) box - if so, see https://forums.mikeholt.com/threads/nema-3r-box-installed-horizontally.28152/

 

[dkistner1111]

TL;DR; reputable manufacturers should list the acceptable mounting orientations for a given water resistance rating.

There's a good chance it's a NEMA 3R (refers to the kind of water resistance) box - if so, see https://forums.mikeholt.com/threads/nema-3r-box-installed-horizontally.28152/

Thank you!