Best Panel Config Help

[NVCYberPro]

I have a EG4 - 6500EX and due to my Northern US and cloud condition I would like to over panel (safely) and reduce the cost of the wire run if possible. The estimated distance from the proposed panel location is just under 300'.

I currently have 12 - SolarEver 410 watt panels and had originally planned on a single string of 12 panels. I am not the best at running all the calculators and understanding the specifications.

We do get sub zero quite frequently and as low as -40 F - High rarely hits over 100 F

I believe I can run 10 safely in a single string but would like to add the extra for the cloudy or snowy days.

Should I do 10 in a single string 10S1P?

Should I do 12 in a single string 12S1P?

Or should I consider 6S2P? The best I see is that this requires 6 AWG? I would like to stay with 10 AWG to save $$$ but open to suggestions.

Whatever I do here I plan to replicate 1 to 2 more times as $$ permits.

I appreciate feedback and suggestions.

Thank you

Module Type
SE-182*91-410M-108N
STC NOCT
Maximum Power (Pmax)410W 308W
Maximum Power Voltage (Vmp) 31.35 29.20
Maximum Power Current (Imp)13.08 10.55
Open-circuit Voltage (Voc)37.12 35.29
Short-circuit Current (Isc)13.96 11.26
Module Efficiency STC (%)20.97%
Operating Temperature (℃)-40ºC ~+85ºC
Maximum System Voltage1500VDC (IEC)
Maximum Series Fuse Rating20A
Power Tolerance0~+3%
Temperature Coefficients of Pmax-0.35%/ ºC
Temperature Coefficients of Voc-0.29%/ ℃
Temperature Coefficients of Isc0.048%/ ℃
Nominal Operating Cell Temperature (NOCT)45±2 ℃

 

[sunshine_eggo]

Temperature Coefficients of Voc-0.29%/ ℃

10S = 371.2V
11S = 408.3V

-40°F = -40°C.

That's a 65°C temperature drop.

-65°C * -0.29%/°C = 18.85% increase in voltage.

10S: 371.2 * 1.1885 = 441.2Voc
11S: 408.3 * 1.1885 = 485.3Voc

I can't remember the PV Voc and Input current limits of all AiO, and I don't want to look it up, so you'll have to figure that part out for yourself.

 

[timselectric]

Overpaneling is not adding panels in series. It's adding strings in parallel.
I would go with 10s2p.
Thanks to @sunshine_eggo for the calculations.

 

[timselectric]

And 10 awg wire.

 

[NVCYberPro]

Temperature Coefficients of Voc-0.29%/ ℃

10S = 371.2V
11S = 408.3V

-40°F = -40°C.

That's a 65°C temperature drop.

-65°C * -0.29%/°C = 18.85% increase in voltage.

10S: 371.2 * 1.1885 = 441.2Voc
11S: 408.3 * 1.1885 = 485.3Voc

I can't remember the PV Voc and Input current limits of all AiO, and I don't want to look it up, so you'll have to figure that part out for yourself.

Here is the specifications - Are the numbers above Open Circuit or MPPT Voltage range - I suspect the latter. If so then the 10S1P maybe to close to the limits?

Also thank you for the computation for temperature. That is really straight forward when you understand a working example.


Thanks again.

 

[NVCYberPro]

Overpaneling is not adding panels in series. It's adding strings in parallel.
I would go with 10s2p.
Thanks to @sunshine_eggo for the calculations.

Thank you Tim

 

[sunshine_eggo]

11S is possible provided it truly never gets below -40.

Given the high Isc of the panels vs. the 18A limit of the controller, I would limit it to a single string and not put additional strings in parallel. Much of the output of those panels would be lost in a 10S2P or 11S2P array.

 

[timselectric]

11S is possible provided it truly never gets below -40.

Given the high Isc of the panels vs. the 18A limit of the controller, I would limit it to a single string and not put additional strings in parallel. Much of the output of those panels would be lost in a 10S2P or 11S2P array.

I would agree if they hadn't have said

I would like to over panel

 

[sunshine_eggo]

I would agree if they hadn't have said

DOH! Missed that!

11S on each would be a ~9% overpanel on each MPPT.

I'm hesitant to put ~28A on a AiO only rated for 18A. Some have published higher Isc limits like 22A, so that's my limit.

 

[NVCYberPro]

DOH! Missed that!

11S on each would be a ~9% overpanel on each MPPT.

I'm hesitant to put ~28A on a AiO only rated for 18A. Some have published higher Isc limits like 22A, so that's my limit.

What I said was:



If I understand correctly I should stick with 10S1P for each MPPT and use 10 AWG wire?

Thanks

 

[timselectric]

I'm hesitant to put ~28A on a AiO only rated for 18A. Some have published higher Isc limits like 22A, so that's my limit.

Well, you know me. lol
I had over 80a worth of panels on a single 18a SCC.
It wasn't an issue, as I figured it wouldn't be.
But just in case, the 20a fuse made sure that it never could be.

 

[NVCYberPro]

Well, you know me. lol
I had over 80a worth of panels on a single 18a SCC.
It wasn't an issue, as I figured it wouldn't be.
But just in case, the 20a fuse made sure that it never could be.

Am I correct that a 10S1P configuration would be just over 11 Amps? I am not sure where th 28 Amps comes in. I have a lot to learn.

Thanks again.

 

[timselectric]

If I understand correctly I should stick with 10S1P for each MPPT and use 10 AWG wire?

That's perfectly fine.
And if you decide you want to overpanel later.
Just add a second string, to the same wiring.

 

[timselectric]

Am I correct that a 10S1P configuration would be just over 11 Amps? I am not sure where th 28 Amps comes in. I have a lot to learn.

Thanks again.

Maximum Power Current (Imp)13.08 10.55

It depends on which number you go by.

 

[sunshine_eggo]

Am I correct that a 10S1P configuration would be just over 11 Amps? I am not sure where th 28 Amps comes in. I have a lot to learn.

Thanks again.

Maximum Power Current (Imp)13.08 10.55
Short-circuit Current (Isc)13.96 11.26

The 410W panels are bolded.

13.08 is the peak power current and 13.96 is the max short circuit current. I rounded 13.96 to 14A and multipled by 2 in the event of 2P config.

 

[NVCYberPro]

The 410W panels are bolded.

13.08 is the peak power current and 13.96 is the max short circuit current. I rounded 13.96 to 14A and multipled by 2 in the event of 2P config.

That makes absolute sense, thank you.