Photovoltaic PV connection ???

[chris34]

Hello again !

Here are my wonderful panels have arrived (8 X of 410 Wc)
I have a question about the section of the cables (for the link between the PV field and the charge regulator, DC, therefore).
The distance is 15 meters, the 4 X PV will provide: 1 W / 640 V / 75 A.
So my anxiety : what is the formula which makes it possible to check the correct section of the cables (Currently I have 4mm² which was fine for the 960 Wc)??

Thanks and have a nice day!

C.

www.aspas-nature.org

[Christophe]

The norm is to put 6mm² to be quiet even if in your case 4 mm² would be suitable for security.

You can do the exact calculation here: https://www.econologie.com/fichiers/par ... XIhXTb.pdf

Screenshot 2023-03-19 at 11-18-02 - 1427995321XIhXTb.pdf.png (60.25 KiB) Accessed 1150 times

For example, if you tolerate a 3V voltage drop (about 1% for 8 panels in series) you need 5mm² for 30m and 28A.
In 6 mm² you will have 2.4 V drop
In 4 mm² you will have 3.6 V drop

Don't forget the grounding (6 mm² too but 4mm² it can pass... it's less important)...

[chris34]

OK ! Thanks Christopher! :-)