Help with beginning wiring for 320w panels

[brandonboosted]

I currently have 6x 320w 24vsolar panels and I’m not sure exactly how I should run them to my 100a mppt charge controller. My controller is 100a 150v max. I only have 1 10awg pv cable for my charge controller. If I run 3S 2P I will be roughly 20a through the 10awg for roughly 15’. According to chart that should be acceptable. Am I missing anything?

 

[Bud Martin]

What is the full spec sheet of the panel?

 

[brandonboosted]

What is the full spec sheet of the panel?

Maximum Power at STC* 320 W
Optimum Operating Voltage (Vmp) 33.7 V
Optimum Operating Current (Imp) 9.50 A
Open Circuit Voltage (Voc) 40.1V
Short Circuit Current (Isc) 10.08 A
Module Efficiency 19.18%
Maximum System Voltage 1000VDC UL
Maximum Series Fuse Rating 15 A
Thermal Characteristics
Junction Box
Output Cables
Module Diagram
12 AWG (2.95 ft long)
Rated Current 30A
Maximum Voltage 1000VDC
Maximum AWG Size Range 10 AWG
Temperature Range -40oF to 194oF
IP Rating IP 67
Operating Module Temperature -40oC to +90oC
Nominal Operating Cell Temerature (NOCT) 47±2oC
Temperature Coefficient of Pmax -0.47%/oC
Temperature Coefficient of Voc -0.33%/oC
Temperature Coefficient of Isc 0.03%/oC
IP Rating

 

[Bud Martin]

Voc of 40.1V, so 3 in series = 120.3V, then add 20% for Voltage rise in cold weather = 144V.
So yes, you are OK doing 3S2P panel configuration.
10AWG wire 15ft distant at 20A (Isc) is ifne, it will be less than 20A in running mode.
I would put in fuse (15A will be fine) DIN mount fuse holder for each string of panel for protection and also allow you to easily disconnecting the panels from SCC when you need to do some service to the system.

 

[brandonboosted]

Thank you for you quick and informative reply. By OK do you mean this would still be ideal? Is there another method that would be more efficient? Also This would be a fuse between the 2P connection? I only have one set of 10awg pv cables I figured when I add 2 more panels I’ll have to run 2 separate cables.

 

[brewmatic]

Yes, 3S2P look like is an optimal configuration for you controller and wiring. I wouldn't install fuses between panels either S or P.

 

[brandonboosted]

Another thing I don’t understand is how many amps will this actualy charge the battery? In parallel it makes sense 80 amps but with the higher voltage will it still be charging at that amperage?

 

[brewmatic]

Another thing I don’t understand is how many amps will this actualy charge the battery? In parallel it makes sense 80 amps but with the higher voltage will it still be charging at that amperage?

What is your battery(s) and charger spec?

 

[brandonboosted]

24v lishen cells, 250a bms, 100a epever 150v max charge controller

 

[Bud Martin]

Simplified, not exact, charging current based on panel power.
320W x 6 panels = 1920W.
1920W/24V = 80A

 

[brandonboosted]

Simplified, not exact, charging current based on panel power.
320W x 6 panels = 1920W.
1920W/24V = 80A

So even tho it’s 120v into the charge controller it always the output to the batteries of whatever the panels put out in watts?

 

[Bud Martin]

Another thing I don’t understand is how many amps will this actualy charge the battery? In parallel it makes sense 80 amps but with the higher voltage will it still be charging at that amperage?

Simplified, not exact, charging current based on panel power.
320W x 6 panels = 1920W.
1920W/24V = 80A
The SCC take the PV input Voltage through smart Buck converter to lower Voltage and higher current to charge the battery.
For example, you panel has Vmp of 33.7V. Imp of 9.5A.
If you put two in series, the Voltage will be 67.4V, the current will stay at 9.5A, so total power = 67.4V x 9.5A = 640W. Charging current = 640W/24V = 26.67A.
If you put two in parallel, the Voltage will be 33.7V, the current will be at 19A, so total power = 33.7V x 19A = 640W. Charging current = 640W/24V = 26.67A.
Both setups will provide the same charging current to the battery.

 

[brandonboosted]

Simplified, not exact, charging current based on panel power.
320W x 6 panels = 1920W.
1920W/24V = 80A
The SCC take the PV input Voltage through smart Buck converter to lower Voltage and higher current to charge the battery.
For example, you panel has Vmp of 33.7V. Imp of 9.5A.
If you put two in series, the Voltage will be 67.4V, the current will stay at 9.5A, so total power = 67.4V x 9.5A = 640W. Charging current = 640W/24V = 26.67A.
If you put two in parallel, the Voltage will be 33.7V, the current will stay at 19A, so total power = 33.7V x 19A = 640W. Charging current = 640W/24V = 26.67A.
Both setups will provide the same charging current to the battery.

Very well explained I completely understand now thank you very much!!