19 minutes ago, Jaco de Jongh said:

Hi Phil, some experience with both and I dont want to publicly start listing the problems my clients have experienced with the new Multi within a month after commissioning. The Quattro is definitely more robust, as were the older Multis in the Alu cases/enclosures. 

Jaco, the reason we join these forums and participate, is for information regarding things like the robustness of equipment etc. Please share this information. 

Edited December 15, 20196 yr by VisN

On 2019/12/13 at 12:03 AM, phil.g00 said:

Two arrays of 3S2P each, with each brought down on its own cable pair into a 150V 70A MPPT.

My thinking is to let these "smaller" strings be the ones that are partially covered by the tree in the morning sun, in order to give my larger strings the best chance of maximum production?

1 hour ago, jasonvanwyk said:

My thinking is to let these "smaller" strings be the ones that are partially covered by the tree in the morning sun, in order to give my larger strings the best chance of maximum production?

The internal circuits of a panel are 3 vertical loops like this UUU.

Shade blocking any cell in a loop takes out that loop's production.

Shading more cells from the same loop doesn't matter. We could shade another 23 cells and we's still only lose one loop.

However, if we shaded 1 cell from each loop the entire panel's production would suffer.

This can have a bearing on whether your panels should be mounted vertically or horizontally where's there is creeping shade..

Now, I know your panels are already mounted, but the same principal applies to panels as well.

What I mean is, Yes use the smaller strings, but wire the strings so that the creeping shade, doesn't creep over both strings simultaneously.

Rather let 1 string work while the other suffers in its entirety.

Now that may not be possible, but if it was that what I'd do.

 

 

Edited December 21, 20196 yr by phil.g00

Thanks - as always that makes sense