Wire Gauge Required Question
For some reason I just can't understand the various wire gauge tables, and I have tried to, so I am hoping somebody will take pity and do all the work! :) One table that I can follow says that for...
Forum Discussion
BFL13 wrote:
Very good information! I didn't realize the 24v and MPPT would let me place the array so far away and still get my amps. Can't wait to try it all out.
You could even choose to undersize your wire if you knew that you would still usually get to Float same day. Aha! More math exercises-- what smaller gauge would get the same AH in daily by 1700 instead of by 1500?
you've got roughly double the current I have, so you will see more power loss even with the "homemade" modified 30A RV cord scheme I used. Instead of roughly a 0.2A loss at 100ft, you'd see about 0.6A loss with my cord, but if it gets you all day sun it's worth it. An extra hour of sun gets you 15AH roughly, loosing .6A for 8 hrs =4.8AH so you STILL would get a 10AH gain! In fact, the break even point would be about an extra 20 minutes of direct sun in 8 hours. And that assumes you don't go below the 15A the panel can supply during the day. Once you go an amp or so below it, then length really doesn't matter, the controller is throwing away power because the battery won't accept it.
you just have to lug around some heavy chunks of cord. I made a bunch of "extension cords" with "anderson" plugs on them from 30A RV cord. One is 15' two are 25' and one is 50'. I just roll out what I need and plug em together. that way I can use the shortest combination needed.
BTW 30A RV cord with the ground soldered to the black or white at both ends to reduce resistance make a not quite #8 extension cord and a "better than" #9 cord. you have one conductor at #10 and the other at #7.
