4 replies to this topic

[Stokeme]

2 years ago when putting my Solar together I purchased 2 - 50ft lengths of this cable. (It was about half the price then, compared to now, with free shipping)
https://www.amazon.c...e?ie=UTF8&psc=1
I got them to extend the Sun reach (from my exterior rear FWC outlet) for my portable Flex panel. It is tough, shielded cable. It has a lot of memory. I don’t think I will need that much length all the time. It would be nice to have 2 - 25’ lengths, instead of just 2 - 50’ lengths. I use all MC4 connectors except at the outlet, which does require a SAE adapter. So, I want to split one of my 50’ lengths in half. This will offer the 2 - 25’s, for a shorter length hookup. I also would like these 2 - 25’s to multitask.
Here is my query ... If I connect the 2 - 25’s, to use as a ~50’ length to match my other non split 50, if used in this fashion, will this unduly compromise my current? Also, If I do this [may have to use MC4 adapter plug(s)] should I use the 2 - connected 25’s, as the 50’ black/Neg cable? Isn’t the Neg just mainly a ground? Save the non split cable to use as the 50’ red/POS cable, because the red actually carries the current?

Edited by Stokeme, 07 July 2020 - 04:42 PM.

[mynxd]

The link posted doesn't point to cable (points to a connector). When I set up my wiring, I purchased a 100" set (red/black) from Windy Nation and some MC4 connectors. I then split the 100" into 3 pieces (45', 30', and 25'). I do not detect a measurable difference between using 1, 2, or 3 pieces. I believe this is due to not actually being able to set the panel exactly facing the sun when in use. You will need both Positive and Negative for the full length to get to your controller. 

[rando]

25' vs 50' won't make a huge difference in your power harvesting.   Go for whatever is convenient to use and gets you to the sun.   

 

The black is the negative wire for the panel (not really ground), but by definition the exact same current flows on the negative wire as the positive wire, so you will have the same losses on both. 

[Stokeme]

Thanks for above info, corrected the link. So, 2x25=50 is, more or less, equal to 1x50=50?

[ntsqd]

In the real world, yes they're effectively the same.

 

In the physics of it, no they're not the same. There will be some loss thru the mid-span connector in the 2X25' configuration. Will you notice this loss? Unlikely, but it is there.