According to plans

[Shawn pavich]

On a solar ground mount ,let's say plans specs say 17 degree tilt . lowest part of the tilt on the array is 18" from grade,on the high end it is 4'4"from grade, let's say there is gradual change in grade (slop) in past installs I allways made my 4'4" on the high end of the slop first that would be my starting point, if the slop is 12" at my last module I would be at 5'4"at the end of my array,never had a issue with doing it like that,tell this last job with the HOA (home owners association)they did not want it higher then what the plans said,thank God we did not have any mods on yet.I tried to get out of it,I had know answer for them when they said why couldn't I start the 4'4" height at the bottom of the slop so that instead of the array rising a foot it would drop a foot,my question is were is the proper spot to start my 4"4 at the high end of the slop are the low end of the slope are does it really matter thanks

 

[ggunn]

On a solar ground mount ,let's say plans specs say 17 degree tilt . lowest part of the tilt on the array is 18" from grade,on the high end it is 4'4"from grade, let's say there is gradual change in grade (slop) in past installs I allways made my 4'4" on the high end of the slop first that would be my starting point, if the slop is 12" at my last module I would be at 5'4"at the end of my array,never had a issue with doing it like that,tell this last job with the HOA (home owners association)they did not want it higher then what the plans said,thank God we did not have any mods on yet.I tried to get out of it,I had know answer for them when they said why couldn't I start the 4'4" height at the bottom of the slop so that instead of the array rising a foot it would drop a foot,my question is were is the proper spot to start my 4"4 at the high end of the slop are the low end of the slope are does it really matter thanks

I am struggling to see what your question is, but in general the solution that keeps the orientation of the array as designed, minimizes or eliminates shading, and minimizes wind loading by having the shortest support poles protruding from the base is the best one. Is the HOA concerned with appearance or wind loading?

 

[JFletcher]

I am struggling to see what your question is, but in general the solution that keeps the orientation of the array as designed, minimizes or eliminates shading, and minimizes wind loading by having the shortest support poles protruding from the base is the best one. Is the HOA concerned with appearance or wind loading?

Probably appearance; it's a HOA after all.

His question is this: panels, on flat ground, are 18" off ground on the low side, and 4'4" on the high side. If the ground slopes divergently from the panel orientation, on which end do you cheat the measurements? In other words, what's more important, the 18" ground clearance on the low side or the 4'4" (max?) height on the high side? I understand the shortest supports being important, but ground clearance for things like lawn equipment seems equally important

 

[Carultch]

Send an RFI (request for information) to your customer, and ask about the intent of the specifications that define the elevation constraints. Confirm whatever your end solution may be, with the engineer of record.

Tell them the situation and the prevailing terrain slope, and show them that it is impossible to meet both constraints at once, so "something's gotta give". And show them a diagram TO SCALE with dimensions, because this is difficult to explain in words.

The reason for a low-point minimum is often to allow a destination for snowfall to clear.
The reason for a high-point maximum would be the mechanical reaction load on the driven post/ground screw/foundation. Or possibly the appearance.

It very well could be that the 18" is intentionally specified, and the 4'-4" is a calculated value of 18" + (NS length of module assy) * sin(tilt)

 

[Shawn pavich]

Apperances, The plans say 4'4" I'm never gonna get 4'4" from one end of my array to the other end when the array is on a slope (little hill) I'm only gonna get 4'4" on my starting point when I run my string line from my 4'4" mark put a level on it by the time I'm level at the bottom of hill my 4'4" mark will change because the grade changed, my array will gradually become higher has the grade changes .my question is were is the proper place to start my starting point,from top of hill so my array will gradually rise,are at bottom of hill my array will then gradually drop ,this is the back of the array,this is the only example I can think of height of disconect 6'7" I can always put my diconnect lower never higher,my plans say 4'4"from grade is that max are is it minimum thanks I hope I'm making sense

 

[JFletcher]

as carultch wrote:

"Send an RFI (request for information) to your customer, and ask about the intent of the specifications that define the elevation constraints. Confirm whatever your end solution may be, with the engineer of record."

Changing the slope of the panels to match your height requirement/restrictions on both ends may affect their performance. If nothing can give (panel angle, min or max height), you could grade the ground flat around the panels so everything is kosher; it would be one way to meet mfg specs and HOA req's.

 

[ggunn]

Apperances, The plans say 4'4" I'm never gonna get 4'4" from one end of my array to the other end when the array is on a slope (little hill) I'm only gonna get 4'4" on my starting point when I run my string line from my 4'4" mark put a level on it by the time I'm level at the bottom of hill my 4'4" mark will change because the grade changed, my array will gradually become higher has the grade changes .my question is were is the proper place to start my starting point,from top of hill so my array will gradually rise,are at bottom of hill my array will then gradually drop ,this is the back of the array,this is the only example I can think of height of disconect 6'7" I can always put my diconnect lower never higher,my plans say 4'4"from grade is that max are is it minimum thanks I hope I'm making sense

It's hard for me to imagine that they would object to the height of the rear of the array simply because the ground happens to be unlevel. Is it possible that the HOA is raising this issue in an attempt to present you with an insoluble problem so that the system cannot be built? Many HOA's have a bee in their bonnet because their state legislatures have passed laws preventing them from blocking solar "just because".

 

[Shawn pavich]

I dropped the back post to 4'4"on the lower side of the slope so now the solar array 4'4" gradually drops down to 3'4" it's all about Apperance,Instead of the array gradually riding up to 5'4"