Couple of wire questions.

[Dforster67]

My supplier only sent 2 rolls of wire instead of 4 that I need for my two 2600 watt arrays. Anyway, I have trenched and am ready to lay conduit and pv wire.
I am laying watertight pvc conduit. Would it matter if I just picked up some 10 awg thhn from Lowe’s or somewhere local to lay along with the 10awg Pv wire? I’d rather use the pv wire but that will delay me while I wait for shipping.

second question, should I run the PV ground through the conduit with the pv wire? And does it need a ground rod at the array? I’m assuming yes. Someone mentioned running the bare ground direct in the trench. But then there’s an issue getting it inside the conduit and keeping it watertight at the house junction.

 

[Dforster67]

Well From what I’ve read people are commonly using thhn or thwn in conduit for pv wire. Maybe the pv wire is used more for direct bury, I’m not sure.

Darn, I forgot already have about 2000’ of 12 awg in the shop which I could double up and would Be more than enough capacity . But I know you aren’t supposed to combine sites smaller than 2/0, I’m not sure which code states that but I’ve heard it. Does anyone know the reason?

 

[chrisski]

For not combining wire that is a thin gauge, I’ve been told because small wire like 10 AWG is so readily available. The thicker wire I’ve been told is not a good idea but allowed to be combined because that is not so readily available and would hold up jobs as its special ordered.

May help someone more knowledgeable on wire if you gave the rating of the wire you were thinking of getting from Home Depot like 7 strand USE-2 or THHN. Not all their wire is equal, even the stuff you have them cut off reels. Somme of the guys cutting the wire can measure the distance, but don’t have electrician knowledge of the wire they’re cutting.

 

[chrisski]

Edit: Deleted double post

 

[Dforster67]

For not combining wire that is a thin gauge, I’ve been told because small wire like 10 AWG is so readily available. The thicker wire I’ve been told is not a good idea but allowed to be combined because that is not so readily available and would hold up jobs as its special ordered.

May help someone more knowledgeable on wire if you gave the rating of the wire you were thinking of getting from Home Depot like 7 strand USE-2 or THHN. Not all their wire is equal, even the stuff you have them cut off reels. Somme of the guys cutting the wire can measure the distance, but don’t have electrician knowledge of the wire they’re cutting.

Thanks.
My 2000’ reel is thhn 12 awg. But I bought southwire 10awg today. Both are 600v moisture resistant thhn , 12 and19 strand and 20 and 30 amp respectively. My pv wire is 1000v 19 strand. Only diff is it’s direct bury rated. My arrays will be about 330v nominal.

 

[chrisski]

I’m not an expert, but I thought the USE2 rating meant it could be buried. I thought moisture resistant could be ran through water, but no necessarily buried.

I had assumed it needed a USE2 rating to be buried in conduit, but not sure.

My PV wire is listed as suitable for direct burial, but I also use a thicker wire that is not PV that is listed as use in conduits in addition to direct burial. I’ve bought this 6 AWG for my solar build https://www.wireandcableyourway.com/xlp-use-2-rhh-rhw-2