Individual PV wires vs positive and negative ran together?

So does it matter if PV wires are ran as individual wires? Or is it just as good to run the positive and negative of each panel in a single wire, such as 10/2:


I thought I read somewhere that running the + and - wires too close together (such as in 10/2) could cause problems, but I think they may have been referring to high powered cables, like battery to inverter.

My desire for the 10/2 is for cable tidyness on the roof of our camper. However, real PV cable would probably be more durable:

https://www.amazon.com/gp/product/B08MLDNM5X/ref=ox_sc_act_title_4?smid=A2TLTYG8U2QKGY&psc=1 (I think this may be a referral link, but if so it's from Will's website) DC loves to make heat so I prefer to keep the wires separate. Also you can spot issue such as the insulation degrading if something goes wrong short wise and such with them separate. That's just me though. Last but not least has to do with the weird cable lengths you end up with doing panels in series. With the wires separate your free to run the positive and negative however you want separately which REALLY comes in handy sometimes.

Last but not least has to do with the weird cable lengths you end up with doing panels in series. With the wires separate your free to run the positive and negative however you want

I hadnt thought of that, good point!

My desire for the 10/2 is for cable tidyness on the roof of our camper. However, real PV cable would probably be more durable:

10/2 Romex is solid copper it doesn’t always work well in vibration prone areas and doesn’t terminate well with standard solar connectors. If you run parallel wires that have the current going in the same direction (both black wires, for example), then the magnetic fields add. The magnetic field in wire 1 makes it harder to push power through wire 2.

If you parallel current running in different directions (black and red wire), then the fields cancel.

Layman's understanding, I could be totally wrong. On

10/2 Romex is solid copper it doesn’t always work well in vibration prone areas and doesn’t terminate well with standard solar connectors.

The link he posted is 10/2 but not the romex solid core house wire stuff but instead multi strand wire so it would work fine.

10/2 Romex is solid copper it doesn’t always work well in vibration prone areas

Yes, thanks. I meant stranded not solid. 10/2 doesn’t necessarily mean Romex or solid core, but I realize that many refer to any number like 10/2, 12/3, 16/3 etc as solid wire.