i got 20 JA Solar 630W modules for 2 250/100 Controllers.
I need a connection advice for this install, is it better to conect 3 strings of 4 modules to one 250/100 Controler ( 7.6kWp) and the other 2 strings of 4 modules to another 250/100 Controller (5kWp).
Another connection option is all 5 strings of 4 modules into a busbar to distribute 12.6kWp between two 250/100 controllers, i think that maybe the voltage tracking for each controller will be adjusting inefficiently at the start but at any moment they could “reach” and work synched
You cant do bottom picture, you can not connect borh pv inputs in parallel on mppt
In picture one your isc is way to high, use the victron mppt calculator
1 Like
already used it and the proposed solution of the calculator is not available with my dealer, my local victron dealer proposed me to use the 250/100 Controller with 3 strings of 4 modules (7.6kWp) and 2 strings of 4 modules (5kWp), but the engineering service of this dealer wich is different from the sales dept, tells me that i cant connect 7.6kW to a single controller.
Here is the data sheet off the 250/100, max input is 70A but mc4 connectors are 30A max each
So you will have to stay below 70A total with temp compensation, nominal max is 5800W
7600W is way too much…
Are your panels all in one direction?
If not, connecting them together or on one mppt will decrease PV power also
all panels are in the same direction, the mismatch between strings is less than 0.5%.
i saw an error on the current and corrected the images.
I already bought the 2 250/100 Controllers and the 20 modules
connect it like picture one but you will still have to split them up differently
on the mc4 connectors, 2 strings is already on max 30A
the 250/100 has 2 sets of mc4 capable of 30A max each, inside the mppt they are parallel connected
Note, that these Panels have a max string fuse rating / reverse current rating of 30A, so paralleling more than 2 Strings requires proper over-current protection. (Cause 2 * Isc > 30A here)