12V PV Array check needed.

[waiapasi2006]

Hello all.

What will be the best setup for these 6 solar panels?

Solar panels information:
6 x 100w
Vmp: 18.9V
Voc: 22.5V
Imp: 5.3A
Isc: 5.7A

I was thinking to arrange my panels into three parallel strings of 2 panels in series.
(2x 22.5V)= 45.0V @ 5.3A x3 parallel strings = 45V @ 15.9A

Or can I run them all in parallel?

I will be using 10AWG for the run.

SCC:
Tracer4215BN- MPPT 40A

Pure Sine inverter:
Input: 12Vdc 200A
Output: 120Vac, 60Hz,17A, 2000W
Continuous Power: 2000W
Surge Power: 4000W

Thank you.

 

[sunshine_eggo]

6P or 2S3P both work.

2S3P might perform a little better during lower light situations, but 6P will have better shading tolerance.

10awg is fine either way. The voltage drop and wiring losses in 6P will be higher than 2S3P, but still worth it if you need shading tolerance.

2000W/12V/.85 = 196A - you're going to need BIG wires between battery and inverter.

 

[rmaddy]

Aren't MC4 connectors only rated for 30A? 6P will be over that.

I'd go with 2S3P or 3S2P. Do the former if you have a lot of shading issues, do the latter if you don't.

Keep in mind that anything over 2P requires a combiner box and fuses on each string.

What is the max input voltage for the SCC? 3S would require 75-80V depending on how cold it gets where you are.

Also keep in mind that 600W of panels at 12V battery is 50A. Your 40A SCC means you can't make use of anything over 480W from the panels.

 

[sunshine_eggo]

Some are rated for 50A.

 

[rmaddy]

Some are rated for 50A.

That would require 6AWG wire. The OP stated 10AWG which is only good for 30A. 6P with these panels will be over 30A.

 

[waiapasi2006]

6P or 2S3P both work.

2S3P might perform a little better during lower light situations, but 6P will have better shading tolerance.

10awg is fine either way. The voltage drop and wiring losses in 6P will be higher than 2S3P, but still worth it if you need shading tolerance.

2000W/12V/.85 = 196A - you're going to need BIG wires between battery and inverter.

I'm more leaning towards the 2S3P setting.
Yes, my concerns now are the wires between the battery and inverter.
Thank you.

 

[waiapasi2006]

Aren't MC4 connectors only rated for 30A? 6P will be over that.

I'd go with 2S3P or 3S2P. Do the former if you have a lot of shading issues, do the latter if you don't.

Keep in mind that anything over 2P requires a combiner box and fuses on each string.

What is the max input voltage for the SCC? 3S would require 75-80V depending on how cold it gets where you are.

Also keep in mind that 600W of panels at 12V battery is 50A. Your 40A SCC means you can't make use of anything over 480W from the panels.

Yes, the MC4's I have are rated for 30A.
I also have on hand one of those inline fuses as well rated at 30A
2S3P will be my route.
The Max input on this SCC is 145V @ 40A.
Thanks.

 

[waiapasi2006]

That would require 6AWG wire. The OP stated 10AWG which is only good for 30A. 6P with these panels will be over 30A.

Correct, I have 10AWG wires.

 

[waiapasi2006]

Also, I want to add this breaker as a disconnect from the PV source going to the SCC.

 

[sunshine_eggo]

That would require 6AWG wire. The OP stated 10AWG which is only good for 30A. 6P with these panels will be over 30A.

10awg romex is rated for 30A.

10awg per awg chart has 60 (30A), 75 (35A) and 90°C (40A) ratings. Marine cable is even higher.

Per:

https://www.anixter.com/en_us/resources/literature/wire-wisdom/pv-wire.html

PV wire is:

• Temperature rating: 90°C wet, 105°C dry, 125°C dry, and 150°C dry

 

[sunshine_eggo]

Also, I want to add this breaker as a disconnect from the PV source going to the SCC.

View attachment 72095

Poor image. No details are visible. Breakers MUST be rated for the necessary DC voltage. Most high voltage AC rated breakers are limited to 30VDC. That breaker says "low voltage" and "400V". Doesn't make sense.

Midnite Solar sells 150VDC breakers in varying currents meant for PV arrays. They tend to run about $15-20 each last I checked.

 

[waiapasi2006]

Poor image. No details are visible. Breakers MUST be rated for the necessary DC voltage. Most high voltage AC rated breakers are limited to 30VDC. That breaker says "low voltage" and "400V". Doesn't make sense.

Midnite Solar sells 150VDC breakers in varying currents meant for PV arrays. They tend to run about $15-20 each last I checked.

This is the one I had bought from Amazon.

 

[waiapasi2006]

10awg romex is rated for 30A.

10awg per awg chart has 60 (30A), 75 (35A) and 90°C (40A) ratings. Marine cable is even higher.

Per:

https://www.anixter.com/en_us/resources/literature/wire-wisdom/pv-wire.html

PV wire is:

• Temperature rating: 90°C wet, 105°C dry, 125°C dry, and 150°C dry

These are the wires i had bought.

 

[sunshine_eggo]

The "~" after the 400V means AC current. Not suitable for DC.

10 AWG and 12 Gauge Red Black Solar Cable Wire with 5 pairs Solar Connectors

www.windynation.com

Their 10awg is rated for 40A.

 

[waiapasi2006]

Midnite Solar sells 150VDC breakers in varying currents meant for PV arrays. They tend to run about $15-20 each last I checked.

Definitely going this route.

 

[sunshine]

I would go with 6p just because it keeps your system at a similar voltage throughout making any latter issues easier to fix and less problematic.
Consider doing away with (eventually) the MC4s since you will have issues with them due to low voltage/high amperage and compatibility between different brands.

 

[waiapasi2006]

I would go with 6p just because it keeps your system at a similar voltage throughout making any latter issues easier to fix and less problematic.
Consider doing away with (eventually) the MC4s since you will have issues with them due to low voltage/high amperage and compatibility between different brands

I'll take a look at those combiner boxes