DIY top of pole rack using superstrut

[Naptown]

When I built the two pole mounts we basically built a teepee type structure with the peak centered over the foundation hole. hung a chain fall from the center and basically hung the pipe from the top. Got 3 tie down straps and strapped the pipeplumb from the three legs of the teepee. Backed a concrete truck up and poured away. Note the most difficult part was keeping the driver from trying to unload the concrete in 2 minutes which played hell with keeping the first one plumb. When he finally realized he was taking more time as we had to stop and replumb he slowed down on the second and it went much more smoothly.

[peakbagger]

I did a rack with the gold superstrut, I find its a lot easier to work with than the regular dipped unistrut. It worked well but its a small array, roughly 11' wide by 8' high. I used two parallel 3x6 rectangular cross section tubes seperated by one strut width set in concrete. I have three struts, two on the outboard of the rectangular tubes and one in between the tubes with a 3/4" rod drilled through. This allows me to pivot the array seasonally and made it easy to attach the panels in place. By mounting a couple on one side and then pivoting the array and mounting a simiar number ont eh other side, I kept things balanced and could install everthing from a step ladder. It has withstood northern NH winds for 5 winters with no issues. I can change the seasonal tilt in about 5 minutes by myself as its pretty well balanced. My other smaller array on the house which is not balanced, requires a hydraulic jack to move it.

I am considering going up to a 12'6wide x 11' high array. On my original design I used 1/2 height strut for the horizontals with some full height strut behind them for stiffness. I will probably upgrade to full height strut when I go with the larger array. The photo is old, I have added 4 panels (2 on each side) since it was taken.

The biggest hassle is bolting the panels into the strut nuts. No matter what, it requires small fingers to fit either a short bolt in from behind the PV flange and into the strut nut or have a stud sticking out of the strut nut and then having to fit on a washer and then a nut. It sounds easy but much hardware ended up on the ground due to big fingers and a tight space.

Do note, the locality does not inspect electrical and I had to self certify the installation. I am not sure if the NEC code allows non engineered racking so do you homework. I have another array on my house that is made with gold unistrut, it is about 10 years old and has no significant deterioration. There is some external staining where it is up next the cedar siding (which is corrosive). I have looked for but havent seen any galvanic issues between the galvanized strut and the aluminum frames. This is an issue with a coastal installation where there may be salt in the air. Rather than going with aluminum or stainless strut (much more $$), I would have made up some nylon spacers to isolate them. I did install seperate ground clips on each panel frame. If I could come up with an easier clip to replace the panel to strut nut hassle, this design would go up quick, once the concrete is poured. I went through 50 bags of sackrete to pour the base and keeping the columns vertical and centered was a pain to do by myself.

I have a basic cad drawing without a lot of dimensions. I can PDF and send it if you PM me.

[totfcboatski]

Anyone have any experience building a top of pole rack system using super strut or unistrut material. I would love to hear some ideas or see some examples or plans.
Thanks!