The Solar Roof Hole

[Brianna]

Previously on Brianna's solar newbie adventure:

In my 2000 36, there is a large enough space between the back of the bedroom drawer bank and the bathroom wall to hang a charge converter and breakers. Pic shows 3/4" ply that is now PL-glued to the thin bathroom wall. The monitor is out in the hall.

There is also a handy 2 inch space between all the framing where one could drill through the roof.

My question is, since this is a major bulkhead, might there also be a metal roof framing rib in that very spot?

Maybe time to invest in one of those cool new stud finders that show you an image.

[whalepirot]

Originally Posted by Brianna

time to invest in one of those cool new stud finders that show you an image.

JuSt got one for my floor heat wire routing. It works rather well in color, too! W/ veteran discount at HD, 60 bucks is way cheaper that trying to move a hole!

[paul65k]

I hung my 150/100 solar controller as well as a Midnight Solar Combiner/fuse box. This is the same compartment that houses the existing Xantrex inverter/charger.

I have already mounted the Victron BMV 712 on the wall as well.

I'll be replacing the Xantrex with dual Victron 12/3000 inverter chargers which will allow me to energize all circuits in the main box, including AC units with the inverter but of course, this is strictly limited by the amount of Battery bank (840 Ah here) and solar production (currently have 1600W).

I added a junction box on the roof and brought all the wiring from the roof into the upper left corner of the cabinets (towards the middle of the roof) and then down the interior corner of the cabinets, past the drawers and into the lower compartment.

I also added a temperature-controlled fan that pulls additional airflow into and out of that compartment to help with cooling in addition to the fans in the Inverter/chargers.

The byproduct of the Dual Inverter/charger set-up is that I will now have a total of 240A of battery charging from the inverters if I ever need additional charging from either shore power or generator power

[Brianna]

Paul, your set up is so fancy. Very inspiring.

I will post a pic tomorrow so you can see where I am thinking of drilling.

[paul65k]

Originally Posted by Brianna

Paul, your set up is so fancy. Very inspiring.

I will post a pic tomorrow so you can see where I am thinking of drilling.

This is how we came through the roof!

[Alpine06]

Hi Brianna,
so my recommendations for the wiring / roof hole.

# Get a combiner box that is large enough. I have a DIN rail in mine to configure all the wires So I can add panels or change my series / parallel layout.
# The box itself has a way it fastens the lid. Take a look at that, sometimes the holes going into the body of the box extend all the way down. This means that you should not add sealant around the outer perimeter of the box as water can find a way under the box and into the roof. Only seal under the box avoiding the holes so water runs in the top and out the bottom. You will know what I mean when you hold the box in your hand.

# Use a small drill bit from the inside of the coach first and then finish with the large bit from either side to prevent blowout on the fiberglass / wood. Especially a spade bit likes to do that.

# Stud-finder is your friend to double check.

# In a superb installation you would install a short piece of PVC conduit from inside the box into the roof leaving it up 1/4 - 1/2" above the bottom of the box. In case the lid seal would ever fail water will not go right away into the hole and into the roof. I did it this way as I have seen this very type of failure on an antenna box before. Alternative you can build up a dam of sealant just around the hole perimeter.

# Use a good cable gland for the wire penetration and only one wire per gland otherwise it will not seal properly.

That is all I can think of in the moment.
Joerg

[Brianna]

Thanks all.
Joerg, I have built such a combiner box AND it will attach to a plastic conduit as you describe.

[Brianna]

Paul, here is the drill site I am considering.
Between the cedar closet (or in your case, the big drawers) and the bathroom wall, there is a 2-1/4" space. Judging by the roof pic you posted above, that is where you drilled. Best left to right location probably based on exact solar panel size/location.

[Alpine06]

Originally Posted by Brianna

Thanks all.
Joerg, I have built such a combiner box AND it will attach to a plastic conduit as you describe.

perfect that looks good !

[paul65k]

Originally Posted by Brianna

Paul, here is the drill site I am considering.
Between the cedar closet (or in your case, the big drawers) and the bathroom wall, there is a 2-1/4" space. Judging by the roof pic you posted above, that is where you drilled. Best left to right location probably based on exact solar panel size/location.

I think that will work great.

I bought a 3/4" 14" drill bit at Lowes for ~$18-20 and it worked great. Go very slowly when you reach the plywood/fiberglass on top and you should be fine!

https://www.lowes.com/pd/IRWIN-3-4-i...Bit/1000791686

[Brianna]

Meanwhile, at the bottom end of the solar system...

[Brianna]

The hole.

Tucked in under one of the solar panels.

[Brianna]

The combiner box and conduit.

[Brianna]

Box in place. Sealed with 3M 5200.

The 5200 is extremely strong and permanent. After it starts to cure I might add a screw for extra caution but I don't think it's necessary.