panel wiring

One of the more confusing issues with solar is matching your panels into a "useful" solar array for your charge controller.

PWM (Pulse Width Modulated) controllers (less expensive type) need around Vmp-array~18 volts for a 12 volt battery bank, Vmp-array~36 volts for a 24 volt battery bank, and Vmp-array~72 volts for a 48 volt battery bank.

Too low of Vmp-array, and your battery bank won't charge. Too high of Vmp-array, your wasting a lot of energy from the array (Vmp-array~36 volts into 12 volt battery bank, about 1/2 of the array Wattage is wasted).

For smaller systems, PWM with smaller panels can be a good fit (less than ~400 Watt array).

For larger system, MPPT controller (Maximum power point tracking--More expensive, tend to be more fancy) use a switching power supply to efficiently "down convert" from Varray higher voltage/lower current down to Vbatt lower voltage/higher current (upwards of 95% efficient).

MPPT generally is more cost effective and better to design with for larger systems (typically 800 Watt or larger array). For "typical" (not cheap) MPPT type charge controller, A Vmp-array voltage of ~24 volts to 100 volts Vmp-array works just fine for charging a 12 volt battery bank...

So, if you need 75.2 volts for the Vpanel input for your charge controller (guessing Vmp-array ~ 75.2 volts), typically that would be 2x Vmp 37.6 volt panels in series, and then make 4x series strings, and connect those in parallel for a 2s x 4p array.

For safety, you should put a ~15-20 amp fuse/breaker (see panel specifications for series protection/fuse) in the positive lead for each array... The output of the "Combiner" circuit goes to a single positive bus bar (and all the negative are connected to their negative bus bar). And run that pair of heavy cables back to the charge controller/battery shed.

Vmp-array of ~75.2 volts sounds like a PWM controller charging a 48 VDC battery bank. Should work OK, but there are more design issues that need to be decided (how far is the wire run from Solar Array to charge controller--Long wire runs means thicker copper cable$).

This webpage does a good job of showing how all that Series/Parallel solar array connections are made:

https://pveducation.com/solar-concepts/series-and-parallel-wiring/
https://higher-octave.com/wire-solar-panels-parallel-series/  (more details on combiner box)

The first solar power system you will make--There are lots of issue that need to be addressed. And you will be doing a lot of learning.

If you are familiar with AC wiring in your home or even DC wiring in a boat/car--All good experience. If you are not familiar with electricity and the math+physical construction--Be very careful. Electrical not done correctly, can be a costly or even dangerous mistake.

I suggest that we start with Paper Design(s) and then, start looking for equipment that will support those designs (costs, availability, what meets your price/performance needs).

To get an idea of what a smaller do it yourself solar power system entails... 2ManyToyz has a lot of photos and comments. Go about 1/2 way down his page:

http://2manytoyz.com/

-Bill