New ground array

[pudding]

Thanks for all the replies. 50m x 40mm twinwall duct ordered yesterday.

Here's a new design, chunkier timber, and only 2 of the triangular supports planned under the 6x3in rails.





As much as it would be nice to use the screw piles to directly support the triangular supports, I don't think there's any way I'd get 4+ of them them lined up on the stony sloping ground to get a frame to sit nicely on them, which slopes about 10degs left to right, and about 10degs back to front. So, I think I'll order 4 of the screw piles, 2 per frame, and use them to attach wires to the timber frame to secure the higher back end down and help prevent any wind uplift. I've used fhbrundle before, and been happy with them too, so they looks a likely supplier.

[AGT]

You could dig a hole near the finished timber support and bury a chain in a mass of concrete and fix it to the posts, or stretch it over a few supports and back down into the ground for extra wind uplift protection?

[pudding]

Interesting idea, but was hoping to avoid digging holes and mixing loads of concrete to provide the weight. Aiming for minimal disruption really.

As the aim is to secure down the frameand panels in wind, rather than actually supporting it as it's not that heavy, I came across these different type of ground anchors rather than ground screws.

https://www.ebay.co.uk/itm/145463563213 ... %3A4429486

https://groundbolt.co.uk/

https://leachs.com/products/bigben-hurr ... 0mm-pack-2

Not sure which to go for, as these seem more appealing and suited to the role rather than ground screws. Thoughts?

[Moxi]

I remember the ground bolt style failing on Frotter's wind turbine at the other place, cannot recall all the facts but I think it pulled at least one clean out of the ground ?

I suppose you can always obtain a sample of one or other ground anchor, install it adjacent to where you are placing the array and then perform a pull test with a suitable sized winch and tripod to confirm the ground holding.

Moxi

[pudding]

Not familiar with that story? I imagine a wind turbine would have pretty huge cantilever forces acting on its anchor points, depending on where it was attached to the mast? Thankfully this solar frame is only going to be 1.2m-ish off the ground at the highest point, so the loads 'shouldn't' be as large as on a wind turbine.

[pudding]

Bit of progress. Twin pipex50m and 8 panels delivered last week, timber and 650mm ground anchors delivered start of this week, so made a start and put together the timber supports, and moved it all into position in the field. Next is to clear the grass to get the concrete blocks it will sit on in a line and aligned, then get the supports standing up and rails fixed on top. At least I'm not missing out on much solar this week!



Top of these supports can be trimmed as the horiztonal rail wont be up at the top of them, about 20cm down.

[Fintray]

Some good progress there, keep it up and get all connected before the sun puts in an appearance.

[Stinsy]

Good progress. How much do the frames weigh? A little trick for pulling cable through the duct involves a rubber glove, some thin nylon string, and a vacuum cleaner…

[pudding]

Thanks. Just did the cable pull an hour ago so missed that trick, but the duct had a pull cord in there and it went fine. Managed to get that done before the rain just arrived, and wired it into the DC isolator. No more on that today now, got a day of helping the family neighbours fruit tree planting in the downpour! Can't really decline seeing as they're letting me put this array in their fields, and we get a pasty out of it for lunch

Each triangular frame must weight 20kg+, and each 4.8m 5x3in rail not far off that, then a ~4m 2x4 diagonal to go across the back of the triangles for some extra bracing, so overall it'll be in the region of 70-80kg I think. - Edited to add a screenshot from a calc, I wasn't too far off. Then there's the 4xpanels to add too to each frame, so another 84kg there.




New cables on the top/bottom left of the DC isolator, going into the ducting poking through the wall on the left.

[Jinx]

Have you got the manufactures instructions for that isolator? I would just double check as often they are required to break one leg more than once.