Panel to Solar Controller Wire Size
As some of you already know, I'm piecing together a solar system. Controller is a Morningstar 45A PWM. Panels will be two 12V 150W wired in parallel. I'm going to be using a combiner box on the roof, ...
Forum Discussion
IV curve is down on page 2 of this:
http://files.sharpusa.com/Downloads/Solar/Products/sol_dow_ND130UJF.pdf
You see the tapering starts down from 8.2 on the top curve just past 12.5v and hits 8 at 15v. The Trimetric is only good to 0.1v but I have seen many times how I can't get that 8.2 anymore and it will only do 8.1 once battery voltage reaches 13 and a bit for sure by 13.5.
They say they get that IV curve from STC but no mention of wire sizes.
Perhaps there is something I am missing about going off STC temperatures and using wire gauge to make up for that.
Also it gets hard to tell if it is IV curve or just high SOC tapering the amps once batt voltage gets to 14 and up so can't see much point in using fatter wire to keep Isc from tapering given that is indeed possible, when amps will be tapering anyway from high SOC.
http://files.sharpusa.com/Downloads/Solar/Products/sol_dow_ND130UJF.pdf
You see the tapering starts down from 8.2 on the top curve just past 12.5v and hits 8 at 15v. The Trimetric is only good to 0.1v but I have seen many times how I can't get that 8.2 anymore and it will only do 8.1 once battery voltage reaches 13 and a bit for sure by 13.5.
They say they get that IV curve from STC but no mention of wire sizes.
Perhaps there is something I am missing about going off STC temperatures and using wire gauge to make up for that.
Also it gets hard to tell if it is IV curve or just high SOC tapering the amps once batt voltage gets to 14 and up so can't see much point in using fatter wire to keep Isc from tapering given that is indeed possible, when amps will be tapering anyway from high SOC.
