Is This Wire Okay To Wire Solar Panels With? Cerro Wire 10 AWG THHN Stranded.

[Solar Trainiee]

Hey everybody, A friend of mine has two spools of 10 AWG THHN Stranded Copper wire, 500 ft One Red and One Black. $150.00 for both. I tried to look up the information on the wire but this is all I could find: Thermoplastic-insulated copper wire with a nylon covering. Sizes 8 AWG through 1000 kcmil feature Cerrowire SLiPWire® Technology for fast and easy pulling in conduit. This 90°C, 600 volt building wire is for use in residential, commercial and industrial applications. Intended for use in accordance with the National Electrical Code® in both wet and dry locations. Gasoline and Oil Resistant II, The jacket is made of clear nylon (polyamide), Color coded, heat and moisture resistant PVC insulation. I would use it to wire and run from a ground mounted and some roof mounted solar Arrays to the inverter. I just don't want to use the wrong wire and have it start a fire in a yr. I've shopped for other wire and its says PV Wire, it's 90 C but 2000 volts and says Sun & UV light resistant. I just wanted to get some other opinions.

Alright, Thanks guys.

 

[ricardocello]

THHN/THWN2 wire is meant for use inside of conduits (PVC, EMT, or Rigid) and in junction boxes.
It is not intended for outdoor use due to the lack of UV protection and thin insulation.

PV Wire is explicitly rated for outdoor use and has a tough outer jacket.
Many of us run PV wire with MC4 connectors from the solar arrays to a junction box.
From there you can use THHN/THWN2 to get to the inverters provided you run it in conduit.

 

[ricardocello]

Also, you should run some green THHN/THWN2 as a ground line for the panel frames to prevent electrical shock.
You will need AWG 6 bare or green wire when you connect to the solar panel frames per code.

 

[ricardocello]

Also, 10 AWG is nominally good for 30 amps, but with solar you should divide by 1.56 safety margin, which gives 19.2A.
So check the Isc of your solar arrays and make sure you are under that.
If not, you will need 8 AWG or larger.

 

[Solar Trainiee]

THHN/THWN2 wire is meant for use inside of conduits (PVC, EMT, or Rigid) and in junction boxes.
It is not intended for outdoor use due to the lack of UV protection and thin insulation.

PV Wire is explicitly rated for outdoor use and has a tough outer jacket.
Many of us run PV wire with MC4 connectors from the solar arrays to a junction box.
From there you can use THHN/THWN2 to get to the inverters provided you run it in conduit.

Thanks for the info..

 

[MakeMePower]

Also, 10 AWG is nominally good for 30 amps, but with solar you should divide by 1.56 safety margin, which gives 19.2A.
So check the Isc of your solar arrays and make sure you are under that.
If not, you will need 8 AWG or larger.

why?

 

[ricardocello]

why?

https://diysolarforum.com/threads/combiner-box-fuses-and-breakers.82443/post-1067826

Fusing & Wire Sizing guidelines for solar panels

Jan 1, 2021

What fuses or breakers do I need on my solar panels

• FilterGuy
• How-to PDF's or Ebook's

R

Post in thread 'Cable Sizing from Ground Mount Array to 18Kpv in the garage'

May 9, 2024

Panel ISC x 1.56 = wire ampacity required

<15 amp 14 awg
15-20 amp 12 awg
20-30 amp 10 awg

E.g. my panels are 11.13 ISC x 1.56 = 17.36 wire ampacity required so I used 12 awg.

Distance and voltage drop are not wire sizing factors for PV DC. After doing the above calculation to determine your required wire sizing you can still do a voltage drop calculation out of interest to make an economic comparison of energy lost vs. additional wire cost to make a decision whether to upsize beyond that.

ISC at my panels is 11.08 x 1.56 = 17.28 wire ampacity required so 12AWG.
BISC at my...

• RibarRanch

• 

Personally, I think a factor of 1.56 is silly, 1.25 should be adequate.