is conduit needed in my attic for pv wires

[chadj]

HELP!
I can't wait to install my system. 4.9kw solaredge system using dc optimizers with 325 watt panels.

Im a diy guy trying to find out if I need to run my pv and ground wires together inside of a conduit, in my attic? Or if they can just be strung across my attic? Either way, would i also need to secure my wiring in the attic? Home is in california bay area and My panels are located on the roof.
Also, is there truly going to be any differences connecting the inverter output to my 2nd sub panel in garage vs connection to my main panel outside?
Thanks all whom attempt to answer.

[Logan005]

I can not tell you what your local code requires, but I would consider it good measure to use conduit. especially if you store Holiday decorations or anything else up there.

[foo1bar]

Im a diy guy trying to find out if I need to run my pv and ground wires together inside of a conduit, in my attic? Or if they can just be strung across my attic?

What type of wire are you looking to run through your attic to get from the optimizers to the inverter?

THWN-2 inside of metal conduit would definitely be one approved way to do it.
But there are others.
THWN-2 without any conduit - not something I'd expect the inspector to be happy with (nor you when you accidentally snag a wire one day, or your significant other hangs the winter jackets from it and causes it to fall down and come undone)

[gmanInPA]

conduit is far less expensive than fire, accidents, or equipment damage. You've already invested in solar, what's a few more bucks for conduit?

[foo1bar]

THWN-2 inside of metal conduit would definitely be one approved way to do it.

I should say THHN/THWN-2 wire.
(once inside the attic I think it's the THHN listing that is being used.
AFAIK THWN-2 is always dual-listed as THHN. (But there might be some manufacturer that doesn't, so I'm correcting my post)

[Sunking]

Only code compliant way to run conductors without a raceway is use a cable designed for it. Cable is not wire, it is a jacketed 2 or more conductor cable. However I know of no professional who would do it. The easiest answer is for Indoors is use EMT, and for Outside use PVC.

[FNG AZ]

HELP!
I can't wait to install my system. 4.9kw solaredge system using dc optimizers with 325 watt panels.

Im a diy guy trying to find out if I need to run my pv and ground wires together inside of a conduit, in my attic? Or if they can just be strung across my attic? Either way, would i also need to secure my wiring in the attic? Home is in california bay area and My panels are located on the roof.
Also, is there truly going to be any differences connecting the inverter output to my 2nd sub panel in garage vs connection to my main panel outside?
Thanks all whom attempt to answer.

Yes, ground (egc) needs to be run with pv conductors in a metal raceway inside a building. And the raceway bonded to that egc if your going over 250 volts.

Ask your poco on where they need the production meter. That will determine what panel to use.

[DaveDE2]

Ask your poco on where they need the production meter. That will determine what panel to use.

Why would the poco production meter need to be placed at the same panel as the PV system? It's just a *net* meter isn't it? I'm planning on placing my poco meter on the line side of the main panel and the PV system inverter output on the line side of a sub panel some 150' away.

[sunnyguy]

A production meter only measures production aka the output of the inverter. The poco may require 24/7 access to the meter and ac disconnect.

[FNG AZ]

Why would the poco production meter need to be placed at the same panel as the PV system? It's just a *net* meter isn't it? I'm planning on placing my poco meter on the line side of the main panel and the PV system inverter output on the line side of a sub panel some 150' away.

Some areas require a dedicated production meter and a/c disconnect within 10 feet of the poco's meter. Like sunnyguy said some and my poco requires 24/7 unrestricted access to both. It all depends on what they require and not what works best.

[chadj]

K so the inverter doesn't need to be near my bi- directional meter. The "wire" running thru my attic will be 2 individual heavily insulated wires. Plus a non. insulated ground. Do those need to be in conduit?

[solar pete]

Short answer is you NEED to check local codes and regulations, but if it were my house they ABSOLUTELY need to be in conduit, no question.

[cebury]

I didn't see this asked.... Are these the DC wires to the inverter or AC run to the main panel? See Sunkings response above

I would always use conduit if DC and that opinion has been expressed to you already twice above.

In my area, they allow The AC Run to be Romex NM (like 8/3 +g) which is jacketed cable to be run through the attic without conduit because it is packaged together already with a jacket around it + they consider the attic to be "inaccessible indoor location". As the cable on exterior become accessible needs the conduit, ditto for the portion from the inverter into the attic is accessible and was run in EMT until above 8 foot and then could be considered inaccessible. The outer jacket was removed to expose the wires when run inside the EMT conduit. Again this is all AC and I'm not an electrician so if you get conflicting advice from your electrician believe them first. And as always your AHJ is always "right". One other forum member told me the ahj was identical in rules to mine as he is in SF city limits.