Schneider Context MPPT 100 - unequal strings?

[knexbuilder]

Question: can you connect miss matched strings to one Schneider context MPPT 100, or do the string have to be equal length?

I have one string containing seven 445 watt panels and another string with eight 445 watt panels due to roof constraints. I am over paneling a little and expect some clipping. VOC is well below max in the 350V range.

Thank you for any help you can give.

 

[sunshine_eggo]

If those are in parallel on the same MPPT, no. You will get:

Nothing if the 8S string is discharging into the lower voltage 7S string creating a short circuit loop.
Little to nothing from the 7S string if operating voltage is a little lower than the Voc of the 7S string.
Nothing from the 8th panel in the 8S string. Will basically perform like a 7S2P array.

It depends on the effectiveness of the MPPT algorithm as to which of the above happen.

If they are connected to two separate MPPT inputs on the same charger (the unit actually has multiple MPPT in it), you're fine.

 

[BentleyJ]

Here is a link to Off Grid Garage. His results tend to indicate you probably can use the mismatched stings.

 

[sunshine_eggo]

Here is a link to Off Grid Garage. His results tend to indicate you probably can use the mismatched stings.

Yep. And get little to nothing out of the 8th panel.

 

[knexbuilder]

I probably should have worded my question a little better, @sunshine_eggo touched on it. I think what I am trying to ask is do these units have multiple MPPTs per unit since it has a connection location that can land up to three strings? I cannot find anything explicit in the manual to say one way or another. The way I am reading the manual it seems like the Schneider Context MPPT 100 functions as a combiner box with a single MPPT inside. Any insights?

 

[400bird]

Single MPPT in the Schneider charge controllers.
It has multiple inputs for parallel, identical strings hooked to the one MPPT.

 

[knexbuilder]

That's what I was thinking, I just needed it confirmed. Thank you all so much!