I'm digging up this old thread as I wanted to share the schematic for the "Solar Carport" addition to my initial setup (Dual PV with diversion).
I will move the already existing 12 panels to be Array 1, and the 20 new panels that will be my carport roof will be my Array 2.
The new panels specs :
STC : Pmax 445W / Voc 40V / Vmp 34V / Isc 14A / Imp 13A.
NOCT : Pmax 336W / Voc 38V / Vmp 32V / Isc 11A / Imp 11A.
I took the NOCT values for my calculations.
Main wiring will from the panels will be 6mm2 (AWG10 ?) and I will need 40m from the carport to the DSSR50.
I will add 8 310Ah cells to add to my existing pack, for a total of 620Ah battery.
I believe these elements will still be appropriate for this install :
- 6mm2 cable from the solar panels,
- 50mm2 cable between the bus bars, the battery and the inverter
- the 620Ah pack handling max power
I think these elements will be enough / OK :
- the 50A DC Breaker after the DSSR50
- the 300A 50mV Shunts
- the 36V / 1200W Heating element
But please correct / advise me better if you think otherwise.
About the shunts : I should switch to 500A, but as the panels will not be in the same configuration (Array 1 being vertical and Array 2 laying flat), they could not reach max output at the same time). Again, please correct me if I'm missing and risking something.
As my setup is growing (and will be even more in the last stage with 32 more panels), I have to be more on point with safety as I'm not understanding everything perfectly. So forgive me my candid question but is it critical to ground the negative side of the battery to the "Protective Earth" of the house ? My understanding was that that this was not critical for safety reason but for interference reasons. (By the way, the chassis of the solar panels are not but will be grounded to PE. Please tell me how wrong I was to be lazy at this thing and risking the electronics)
Bonus question : how would your DMPPT100 fit in this setup ? Should I wait for it before setting up the heating side of my setup ? Because, I will go though the hassle of fitting 5 heating elements at the bottom of recycled water boiler tank and as far I understood the DMPPT100 will act as a switch between different resistors... So what do you think Dacian, should I be patient ? But no pressure on you, of course ;-)
Cheers,
Bjorn
PS : on this schematic, Only array 2 is new. Please check the wiring of the DSSR50 / DEXT16.