Thanks; this is perfect. I will use 4awg. Thanks so much for all the help.

I used Southwire voltage drop calculator for your specs.

Sounds like 6 gauge would be fine and you don't have to mess around trying to make 4 gauge fit in the Classic .

You can use a 60 amp breaker at the Classic for PV in . All your PV strings ( 3) in the combiner would have their own 15 or 20 amp breakers ( usually 15 I think )

Voltage Drop

Minimum Conductor Size

2.34%

10 AWG

1 conductor per phase utilizing a 10 AWG Copper conductor installed Direct Buried will limit the voltage drop to 2.34% or less when supplying 25 amps for 50.0 feet on a 112 volt 1 phase system.

Engineering information only

30

Amps Rated ampacity of selected conductor

1.1417

Ohms Resistance (Ohms per 1000 feet)

0.05

Ohms Reactance (Ohms per 1000 feet)

0.9

Power Factor

3.3600000000000003

Maximum allowable voltage drop at 3%

2.623

Actual voltage drop loss at 2.34% for the circuit

https://www.southwire.com/calculator-vdropLarry