So I’m soon to add my final 280W panel and have an end result of 2*250W(8A) and 2*280W(9A) for a total 1060W through my 40A Epever Tracer all at 24v.
Not really fussed at the small difference between the panels, but recently heard that MC4 plugs are only rated to 20A, and as I have all three (current) panels on a three way MC4 joiner before coming down through the roof on one pair of 6mm wires down to the controller, I’m a bit worried I might blow either the 20A inline fuse or overdo the 20A rating of the plugs.
I can easily up the fuse, but it’s there to protect the plug so not really a good idea!
Lithium will take whatever it can at max input so the potential 30-34A from the set all in parallel in good sun could be a problem?
I’ve already seen a 20A input via the solar once when I came out of a shady park into the good sunshine around 11am, so I’m now wondering how to safely accomodate the extra panel best!
I think I basically have two options, without another wire penetration to the controller (or extra controller)
1) to series and then parallel the two pairs 250-280=530W (twice) thus dropping the amp input and letting the MPPT sort it out inside (also potentially keeping the voltage higher for longer in low light)
2) disconnect one of the panels and only connect when it’s needed in low light/winter conditions
I’m heading toward (1) as it’s not a manual control so less likely to go wrong, but know that some here say parallel is best no matter what!
At this point I’m not able to do another hole in the roof as SWMBO is anal about the potential leak factor