Requirements
- Waterproof
- Room for future expansion
- Maintainable/Servicable
Underside Pass-throughs
My favored concept uses a 3 inch threaded PVC nipple. It will pass through a ~3 inch hole drilled/cut though a flat area in the steel floor as well as the insulation and top floor as well as a waterproof junction box with a ~3 inch hole in its base. 3 inch female threaded PVC flanges will capture the nipple between the inside floor outside as well as capture the waterproof junction box. Sealing material will be used at the perimeter of the junction box and the junction box hole between the box and the exterior floor. Holes will be drilled into 4 sides of the junction box with cable glands providing the waterproof barrier into the junction box.
Roof Pass-throughs
The roof pass through will use a similar technique, though multiple smaller holes and PVC may be used to accomodate large dimensioned terminal boxes to maximize room for expansion. VBH would aid in securing.
To keep below the top of the rail and allow nestling under "deck" or solar panels, height is of interest:
2.3" high 3x4 10mm diameter wire
~2" high possibly up to 6 inputs up to 15mm
1.65" high up to 3, inputs up to 10mm
2.17" high 3 and 3 or 4 and 4 high not sure gland size
This is the best option I've seen so far: 2.16" (internal) high 4 glands up to 15mm
2" (internal) 8 glands up to 15mm
2.2" (internal i think) plenty of glands not sure of gland size
2.3" lots of room for glands, could probably support up to 14mm diameter cable
This might be the one 2.44" 10 glands, up to 14mm.