Wire AWG sound ok? CCA 12g for my setup?

[kenfused]

Hi, I have 4 panels, to run 2s2p and will end up having about 15-16A at 70V to my SCC.

Would 12AWG wire CCA be ok for this? about a 35 foot wire run.

Thank you!

 

[OzSolar]

I assume you're talking about Imp so the Isc will likely be ~20 amps. Last I knew NEC requires Isc x 1.56 for sizing wire on solar runs. 31.25 amps puts you up to #8. In practice you'll likely be fine with #10 but that's not the official answer.

 

[kenfused]

Thank you!

 

[Bud Martin]

12 Awg CCA (Copper Clad Aluminium) wire has less Ampacity than the same gauge pure copper wire, 12 Awg CCA is rated at 15A.
You do not have pure copper wires?

 

[zanydroid]

Surprised to see CCA mentioned, I thought you would need to do extra work to get it still.

Since CCA is new, on top of having to size up. since it is a new product it’s quite arguably unwise to use it for solar where you want the equipment to last 20-30 years. Not enough longevity data on this thing.

I doubt you’re saving much money on a #12 35 foot run.

Why are you considering it?

 

[OzSolar]

Good catch on the CCA. I totally missed that.

 

[Shimmy]

Since CCA is new...

Huh? It has been around for over 30 years. (Edit-- actually 50 years)

 

[zanydroid]

Huh? It has been around for over 30 years.

I'm sure the production process is old but it's being pushed for wide application in the US in a new application (small conductors & in terminals listed for Cu + I believe exempt from explicit testing for CCA) by manufacturers & has only been in NEC since 2023 cycle. So there just aren't that many installations using it.

If CCA has been used overseas with analogous terminal types, OK then (though often we do not use identical terminals to overseas).

I guess if someone installs the CCA in Al/Cu compatible connectors out of an abundance of caution it's probably no less risky than using aluminum.

But it's still experimenting for a small savings in absolute terms.

 

[Tomthumb62]

Hi, I have 4 panels, to run 2s2p and will end up having about 15-16A at 70V to my SCC.

Would 12AWG wire CCA be ok for this? about a 35 foot wire run.

Thank you!

Having used CCA for a shorter run of suitcase panels, I really regret it now. Yes the CCA is cheaper and I think fine in some situations, but since in my case I have limited solar production (it's a camp trailer), the voltage drop of CCA over copper just wasn't worth the savings. I'm still getting some production from those suitcase panels, but I know I'm losing some due to the lower conductivity of CCA. I will be replacing it with real copper wire down the road, so I actually DIDN'T save money had I done it right the first time!

Will has good wire listed on his site for a decent price: https://www.mobile-solarpower.com/wire-and-connectors.html

 

[Shimmy]

I'm sure the production process is old but it's being pushed for wide application in the US in a new application (small conductors & in terminals listed for Cu + I believe exempt from explicit testing for CCA) by manufacturers & has only been in NEC since 2023 cycle. So there just aren't that many installations using it.

If CCA has been used overseas with analogous terminal types, OK then (though often we do not use identical terminals to overseas).

I guess if someone installs the CCA in Al/Cu compatible connectors out of an abundance of caution it's probably no less risky than using aluminum.

But it's still experimenting for a small savings in absolute terms.

I have to dig out my old code books, but pretty sure it has been in the NEC since before 1990. CCA was a solution to terminal compatibility. I had it used on projects for large wire (250MCM and up), but agree the economics were never there for small wire.

 

[zanydroid]

I have to dig out my old code books, but pretty sure it has been in the NEC since before 1990. CCA was a solution to terminal compatibility. I had it used on projects for large wire (250MCM and up), but agree the economics were never there for small wire.

Ah OK. They did a massive copy-paste of CCA verbiage into NEC 2023 for new applications, maybe to explicitly say it's allowed for terminal compatibility without re-listing.

Haven't really been interested for my projects because the savings just are not there for personal projects (probably there for large builders knocking out bunch of houses at a time or for the metals commodity market, but that's irrelevant to me). And it would take more time to source CCA anyway vs copper or aluminum.

For HVDC connections I think the advice is anyway to use connectors like Polaris that are dual listed so you could have already use good old aluminum if you want to save money. But then you get into trouble like, are your MC4 or like connectors listed for aluminum, if you use CCA is it worth being forced to effectively go down a size or half size (since MC4 has a limit of #10, 25A @ 60C vs 30A for copper). Maybe if you already need a combiner or are using larger connectors good for large connectors it's cost & complexity neutral for the stuff that is not wires.

 

[Hedges]

but agree the economics were never there for small wire.

Never were before. But have you priced copper wire ... lately?

https://www.lowes.com/pd/Southwire-Romex-SIMpull-250-ft-12-3-Non-Metallic-Wire-By-the-Roll/3136775

 

[Shimmy]

For HVDC connections I think the advice is anyway to use connectors like Polaris that are dual listed so you could have already use good old aluminum if you want to save money.

Copper cladding has some extra benefits IIRC. I think the big one was less problem losing connection integrity over time. Not an issue for compression lugs, but on small terminals it can help.

I don't think I have ever seen fine-stranded aluminum though; can't imagine it working well.

 

[Hedges]

Copper cladding has some extra benefits IIRC. I think the big one was less problem losing connection integrity over time. Not an issue for compression lugs, but on small terminals it can help.

I don't think I have ever seen fine-stranded aluminum though; can't imagine it working well.

I bought some (Jumper cables) with fine strands because I didn't understand "Copper (CCA)" meant aluminum.
At least they were cheap and not in a (fire) safety critical application.

 

[kenfused]

Surprised to see CCA mentioned, I thought you would need to do extra work to get it still.

Since CCA is new, on top of having to size up. since it is a new product it’s quite arguably unwise to use it for solar where you want the equipment to last 20-30 years. Not enough longevity data on this thing.

I doubt you’re saving much money on a #12 35 foot run.

Why are you considering it?

Mainly because I had some laying around…