Detailed Solar to Inverter

This is the wiring options for my 40kw ground mount solar system and 2 x Flexboss21 inverters about 220ft away. The 40Kw solar system is split between 3 separate 70ft arrays.

I installed

Materials List from Top Down

There are two Main Solar Wiring Options

Options 1: PV wire

Option 1: PV Wire Direct Bury

Use 1” Schedule 80 conduit from from the top of the solar array

  • Use 1” Schedule 80

Option 2: THHN Wire Buried in Conduit

Title

. Details

Selecting Your Wire

  • Use pure copper or tin coated copper

  • Select the minimum gauge based on NEC guidelines (14 awg = 15A, 12awg = 20awg, 10awg = 30awg, Open Air Direct Burial non bundled

  • Derate if in conduit or has a high temperature.

  • Double check minimum gauge with 3% max voltage drop. (175ft long x 2 = 350ft)

  • Make sure the wire is UL rated for UV exposure and direct burial

10AWG PV Wire, OD 0.23”: https://amzn.to/4nCISyB

12AWG PV Wire OD 0.21”: https://amzn.to/464N5VZ

My Solar Array is 175ft from the inverter. You should ensure that the voltage drop stays less than 3%. Multiply the wire length by 2 because there are two wires per circuit. Each set of 11 panels outputs approximately 550V when connected in series and 2 sets of 11 can be connected in parallel resulting in a total current of 17A. With a 10AWG wire the design calculator says we would have a voltage drop of 2.22%, well below the 3% required.

Solar Connectors

There are a lot of cheap junky solar connectors out there. The best balance between quality and price that I have been able to find are the BougeRV connectors.

Video How to Crimp: https://www.youtube.com/watch?v=VrKYlQPHfno

Solar Cable Management

It is important to keep the solar wires from dangling and getting tangled. Solar clips provide an easy way to make your solar panel wiring look nice and sharp.

Grounding The Solar Panels

Disconnects

Sizing Your Conduit

PDF with Tables and example calculations for sizing your conduit

https://pdhonline.com/courses/e276/e276content.pdf

Flexible Non-Metallic Electrical Conduit: https://amzn.to/4mdvq3b

Electric Non-Metallic Conduit (ENT): https://www.homedepot.com/p/Cantex-3-4-in-x-10-ft-Gray-Non-Metallic-PVC-Schedule-40-Conduit-A52AG12H/202352534

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