Setup, Would there be an imbalance with this setup?

[jflorey2]

Hey guys, just wondering , but would this wiring setup have problems? i cant think of any, but i'm just checking.

It will not be balanced and the 75W panel will act like a 20W panel. But it will work.

[Aspire]

Shed Solar setup..png
So. how should i wire this? as the picture explains, i think, the 4x20W array is in series with the 1x75W panel, and the final section is 2 20W panels in series with each other, tacked in. Yes, or No?, did i wire this correctly? I'm a very visual person, pictures help a lot.

[Aspire]

little late to the party jflorey2 , already past that. now i'm just trying to get the most capacity out of what i got.

[Aspire]

Also, anyone use Stud type circuit breakers instead of Fuses, and have experience with them? i was thinking to use them for the inverter protection instead of fuses.

[sensij]

sketch.JPG


I'm not following your colors. This is what I'm describing (I think you can fill in the numbers).

[Aspire]

Alright, thats exactly what i have, but i started with the 4x20 and 75W, and added the 2X20W on to it. I Colour Series bridges differently to make it pop out to me.

[sensij]

Alright, thats exactly what i have, but i started with the 4x20 and 75W, and added the 2X20W on to it. I Colour Series bridges differently to make it pop out to me.

That might be what you intended, but I don't think it is what you drew. I don't see a parallel connection on the DC+ to the charge controller in your sketch.

[Aspire]

the pink and Grey lines aren't a parallel connection?

[SunEagle]

OP has already said the system voltage is 24 V... that is over 1000 W of PV on a 40 A cc. Plenty of capacity there.

OP has already said they are 12 V panels. 2 in series is appropriate for a 24 V system with a PWM controller. As I suggested above, 4 x18 W panels could be put in parallel first, and then put in series with the 75 W panel, to get the right voltage and match the current within the string. A 2nd string could then be used in parallel to that, with 2 more of the 18 W panels in series.

Op will have 183 W available if wired as I suggested. That is probably around 7 charging amps under ideal conditions.

The 1500 W inverter could pull 62 A when fully loaded.

Will the OP's battery be happy with only 7 A of charging and a discharge requirement of up to 62 A? Probably not, but as marine batteries, they might handle the higher discharge better than true deep cycles, as long as they don't get asked to provide it too often.

This is *not* a well designed system, but for learning, and if the parts are cheap enough, I don't think there are any gross violations of compatibility.

Well I was going with the specs on that CC the OP showed and it had the 48v input and 500w panel limitations.

Now you know that a 12v panel really has a Vmp ~ 17 to 18v and a Voc about 23 to 24v. So if he wired two of them in series his total Voc could be 48v. I just want to warn the OP not to exceed the VDC input max.

The problem is using the mixed bag of 20w & 75w panels without letting the Vmp or Imp of each "parallel string" to exceed what I have heard as a 5% difference.

I want to OP to use as much as they can but I also don't want them to waste their money on a system that will kill the batteries.

[sensij]

the pink and Grey lines aren't a parallel connection?

The grey line is tapping the middle of the series connection between the 4x18 W parallel group and the 75 panel. That is no good. The grey line should extend all the way to the red line connecting directly to the charge controller.

[Aspire]

48V? wat?

[Aspire]

Shed Solar setup..png
sensij ok, here. i redid mine.

[SunEagle]

48V? wat?

The specifications shown for that Sun YOBA 40A CC indicates the maximum open circuit DV voltage that the panels can send it is <= 48V.

Now depending on where you live and how cold it gets a the panel Voc can increase just as the sun comes up. If the total DC voltage from any "string of panels" exceeds 48V that CC may have a problem or fail. I don't know since I have no hands on experience with that CC.

So at best you can wire only 2 of those 20W panels in series.

[sensij]

Shed Solar setup..png
sensij ok, here. i redid mine.

Yep, you got it. It won't handle shade well... if any of the 4 panel group gets partially shaded, it will affect every panel in that string, but again, I think this is the best you can do with what you've got.

[Aspire]

SunEagle Ah. i see, well, its gets to about -30C at the most... but shouldn't it only be 40V MAX Voc... but yeah, 8v isn't much wiggle room.