Roof Solar Install

I have installed one conventional solar panel on the roof. This page shows the details.

Cable Pass Through

I wanted to pass multiple cables through the roof, including the ones for the solar panel. I found this https://www.rvwithtito.com/articles/run-cable-through-rv-roof and wanted to something similar. I prefer to use Bud Aluminum boxes, so I obtained a waterproof junction box (Bud AN-2854-A, KIP68 rated) and first cut holes using knockout punches for the cable pass through on the sides and conduit on the bottom, and painted it white:

I then installed waterproof cable pass through connectors on all side and sealed them with some Dicor sealant just to be extra sure:

Then, a hole was cut in the roof, again using a knockout punch, for a piece of conduit to pass through:

The conduit was dropped down into the hole and the box placed on top of that to test the fit:

I then installed it with Butyl tape and Dicor, sealing around the conduit inside the box, under the box and all around the box:

Panel Install

The solar panel was heavy and unwieldy. I didn't want to have to drag it on and off the roof multiple times to measure and fit, so I made a jig out of birch plywood that was the shape and size of the frame and had holes where the mounting brackets would mount. Here is the jig with the mounting brackets installed. I used RV Solar Store Sticky feet:

Once I was sure that everything would fit, I took the jig and placed it on the panel. You can see the VHB tape on the bottom of the brackets. Once that sticks, it is stuck, so everything has to be right the first time, so I checked the fit at every stage of the process:

I then drilled two holes in the brackets and put the jig back up on the the roof to mark and drill mounting / locating holes in the roof:

I then separated the two parts of the brackets and installed sheet metal screws in the bottom half of the brackets and removed the tape:

Using the screws as a guide, I installed the brackets on the roof and tightened the screws:

I then took the jig, drilled holes in the panel to match and attached the other half of the brackets on the panel using Loctite 243 and double nuts:

Then, with help, the panel was lifted up to the roof and the two halves of the brackets attached to each other and sealed them with Dicor lap sealant:

I wired everything up and the panel was working:

Since there was an empty spot at the front of the roof, I added one more panel. The mounting feet for that one needed to be on a flat portion of the roof, closer together than the panel edges. I used aluminum angle to attach to the feet and support the panel:

So the roof now contains two panels:

There was still some room around the air conditioner, but I could not find rigid panels that would fit there, so I decided to install skinny flexible panels. They really can't go directly on the roof, as the roof is not flat and they will not be well supported. There is also a risk of them wearing out and having to replace them. Mounting to the roof directly with adhesive could damage the roof if removed. In addition, there should be space for cooling air below the panels for maximum efficiency, but the panels are too flimsy to stand off the roof alone. After looking at things various people have done, including more ideas from rvwithtito.com, I decided to mount them some distance above the roof using 3D printed supports, six per panel. The supports are curved on the bottom to fit the roof and have an elevator bolt protruding from the top to attach to the panels, using the mounting holes that come with grommets in the panels. The supports also have holes for sheet metal screws to protrude from the bottom and attach to the roof. Each support is unique and fits a particular corner or edge of a panel, and the shape of the roof below at that location. They are made of ASA plastic that is UV resistant, and shaped like a NACA airfoil just because I could:

After the elevator bolt is installed, the hole on the bottom of the panel is filled with Dicor lap sealant to keep water out:

Then VHB tape is attached to the bottom and the sheet metal screws are put in the holes. This particular bracket holds a corner of two of the panels, so it has two elevator bolts and three sheet metal screws:

I used 3M 5962 VHB tape. It is specified for both plastic and painted metal, and is the right thickness to take up any minor gaps.

Here is a top view of this bracket:

I made cardboard 3D printed Plastic and and wooden templates to make sure everything would fit as needed and drilled all the mounting holes in the roof. I removed the backing from the VHB tape and using the sheet metal screws as a placement guide, attached all the brackets and tightened the sheet metal screws to compress the VHB tape. Everything was then sealed with Dicor lap sealant.

I then took each flex panel and bonded them to pieces of twinwall polycarbonate using 3M 4200 marine adhesive. I made aluminum strips for the edges. This created a fairly rigid sandwich that could be mounted on the elevator bolts, but removed easily if the panels failed. Here is a closeup of the installation after a year and 10,000 miles. There is a little warping in the corner of the panel, due to the hole being slightly offset, but there is no sign of them peeling away from the twinwall backing:

Note that I am using Nylock nuts. The hardware is stainless steel and you MUST use anti-seize or the Nylock nuts will gall and have to be cut off to be removed:

I used Loctite Marine Grade Anti-seize.

Here is the finished installation of the three panels:

Here are some of my other sites:

My RV ham station: https://sites.google.com/site/marksmobilehamstation/

My Controleo2 based SMT Reflow Oven: https://sites.google.com/site/markscontroleo2build/

My TS-590S MODs including a buffer board install for a panadapter: https://sites.google.com/site/marksts590smods/

My TCXO Boards to replace the SO-3 in Kenwood TS-590 radios: https://sites.google.com/site/markstcxo/

An explanation of various TCXO Characteristics in Kenwood TS-590 Radios: https://sites.google.com/site/markstcxomeasurements/

Modifications to allow use of an external clock in a Perseus SDR: https://sites.google.com/site/perseusmods/

How I use Spectrum Lab Software to do frequency measurements: https://sites.google.com/site/spectrumlabtesting/

Pictures I took of the 2017 Total Solar Eclipse from Menan Butte, Idaho: https://sites.google.com/site/marks2017eclipsephotos/

Revised April 9, 2022