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Running PV wires in an attic/indoors/basement guidelines?

OK, so I've located a discreet location where I can run 10 AWG PV wires off the roof, and then discreetly run them in either flexible metal conduit or PVC conduit all the way around the house under the eaves behind gutters.

I am strongly considering this as it simplifies things (especially the final connection to the EG4 unit (which receives MC4), I don't have to drill a big hole in the roof, and I don't have to switch back and forth between PV and 10/2 and back again.

To keep wires off the roof (including the grounding wire, I would run them in conduit and support the conduit above the roof with support screw in conduit clamps/supports.

From the EG4 user manual.


eg4.png
 
Cptx said:
Thank you all for the feedback.
Other than the panels and mounting hardware, this is my initial list.

View attachment 164027

View attachment 164026
Click to expand...
If you are planning on getting this stuff inspected, be VERY weary about buying anything on Amazon. Do yourself a favor and ensure 100% that your breakers / disconnects are listed. Sure, they cost quite a bit more, but having to tear it all out and end up purchasing the "good" ones in the end is a hard pill to swallow. If you don't plan on having an inspection, just cowboy it and I'm sure it'll be perfectly fine.
 
Thanks all for the advice.

What would be the preferred method with my situation (no inverter....5X400 watt in series roof panel array to EG4 outside compressor that has MC4 receiving connections if I want to avoid going through the roof with a junction box and then back out again?

Option one:
PV and ground wire from array to 10/2 MC via DC isolator, run the 10/2 MC around the house under the eaves/soffit to DC disconnect box adjacent to the EG4 outside compressor and then back again to PV (what's the best way to go back to PV cable from 10/2 MC ?) for the final connection to the EG4 outside compressor with MC4 receptacles......ground wire to house ground.

or

Option two:
Go PV and ground wire all the way around in flexible metal conduit (DC solar disconnect switch when the PV gets off the roof, then another DC disconnect box adjacent to the outdoor EG4 compressor).....ground wire to house ground.

or, is there a better option?
 
This is a picture of the MC4 receptables on the 12K hybrid EG4 outside unit.
The instruction manual and the construction of the unit guide the consumer into utilizing PV cable as the final step if running directly off DC from the solar panel array.
If using PV cable anywhere except the roof isn't recommended by NEC, what is a reasonable modification or work around for that final step?
MC4.png
 
Cptx said:
This is a picture of the MC4 receptables on the 12K hybrid EG4 outside unit.
The instruction manual and the construction of the unit guide the consumer into utilizing PV cable as the final step if running directly off DC from the solar panel array.
If using PV cable anywhere except the roof isn't recommended by NEC, what is a reasonable modification or work around for that final step?
View attachment 165434
Click to expand...
PV is fine, it's single conductor PV hanging out by itself that is not fine.

Well this is EG4 tier stuff of the sort where they couldn't be bothered to change even a wiring compartment to be UL/NEC friendly so it may not be possible to be 100% compliant. In Mainland Chinese wiring standards (presumably these ACs are meant for some low density villages in Tibet, Xinjiang, or inner Mongolia) it is more acceptable to have some short lengths of exposed wire outside of conduits than it is in the US.

I guess if this thing is ETL listed (I see a mark for it in the screenshot) and says you can use bare conductors in the instructions you might get an out with the inspector and insurance.

Maybe put a waterproof electrical box (bell or PVC) close to the AC and run individual PV the last stretch through a two hole gland on the bell box. If there is a cable type that has individual PV conductors that would help. Another way is to sleeve it in some liquidtite and secure the end of the conduit somehow someway near the AC. Since EG4 hates you doing a good job you can't just screw it into a knockout on the AC.

No clue how I would handle the grounding for the metal parts.

I would not be surprised if this AC is not up to snuff with AFCI or GFP. For the AFCI case because it's not needed in most overseas places. For the GFP, probably there are rules overseas but I don't see a ground port for the PV side.
 
Thank you very much for the detailed reply and excellent problem solving options.
 
No problem. What did support say?

You could potentially use an isolator switch next to the AC as the junction box. That would also let you transition to THHN while in conduit if it's a long run.

Don't remember if mentioned importance of matching MC4 brands but you should definitely follow that bullet point in the instructions. Unfortunately those instructions you shared above do not give an example NEC compliant installation.
 
How do they expect you to match MC4 brands, with an inverter that comes with MC4 connectors on it? Do they sell / supply those exact MC4 connectors for you to make your own ends with?
 
wheelman55 said:
Cowboy it. Very funny. Try explaining that to your insurance company after something fails and causes a fire.
Click to expand...
I agree…Anyone that expects an insurence “ suit” not to look for any way to avoid payment as you didn’t comply with every known rule in existence is being silly.
build the system so that if it fails it won’t take your house..build a small climate controlled structure that contains it outside… only the AC wires enter the house…and do those to code with good skill.This is a tough goal to acheive unless you have unlimited money and sub it out or get all the inspections as required.
the insurence industry is not in business to help you any more than sharks are your friends.
J.
 
cs1234 said:
How do they expect you to match MC4 brands, with an inverter that comes with MC4 connectors on it? Do they sell / supply those exact MC4 connectors for you to make your own ends with?
Click to expand...
As long as the MC4 brand is listed in the specs (and hopefully trust) or printed on the connector you can match.

There are also some MC4 compatible ones that are UL listed for multiple MC4 brands.

Now if you don't even know what brand it is on the inverter or AC... ?‍♂️
 
Another thing that can be done is reterminating. On a MLPE or panel this is fairly easy (though one would probably want to get clearance that this does not void warranty. It is possible to do so). This can be done preemptively to meet code or reactively as a repair.

On this unit, I dunno. Need to look inside the wiring compartment to see how much spare wire there is and how the MC4 connector is attached to the knockout.
 
zanydroid said:
I would not be surprised if this AC is not up to snuff with AFCI or GFP. For the AFCI case because it's not needed in most overseas places. For the GFP, probably there are rules overseas but I don't see a ground port for the PV side.
Click to expand...
Hi Zany. As some of you are aware I had a PoCo run in where they investigated this unit then eventually waved it off as OK. One thing I thought I learned, was UL1741 compliance requires Arc Fault and Ground Fault - IS THAT CORRECT? Asking, not saying I know...:)

Can we trust China if it says it complies :eek::ROFLMAO:

20221130_161923 (1).jpg
 
I’m staring to understand the issues with directly DC powered appliances that have a self contained MPPT and inverter (very difficult to stay within NEC guidelines; then there’s all the underutilized power)

For future such appliances, I wonder if there is an easy way to incorporate optional add on battery banks as part of the intended design. Doing so, may also enable such appliances to be in more accord with NEC, etc.
 
Yes, there are different interpretations of the word “conforms”. ?
 
Plum Crazy Rob said:
Hi Zany. As some of you are aware I had a PoCo run in where they investigated this unit then eventually waved it off as OK. One thing I thought I learned, was UL1741 compliance requires Arc Fault and Ground Fault - IS THAT CORRECT? Asking, not saying I know...:)

Can we trust China if it says it complies :eek::ROFLMAO:

View attachment 165665
Click to expand...
It has the mark and it's sold by a US based company so you have someone onshore to yell at or get Intertek to yell at on your behalf.
 
The unit is definitely listed to UL1741 see: https://ramuk.intertekconnect.com/W...a67e94b8814c30c88625883700152c93?OpenDocument

I'm not sure if UL1741 covers arc fault, and ground fault for solar. But if it had listed arc fault it would also be listed for UL1699 which is the standard for pv arc fault, which this unit doesn't seem to be to listed to. Also on page 24 on the manual seems indicate that ground fault protection must be provided, but not that it is not included.
 
EG4 did provide these PV cable MC4 terminals.
Thus, I suppose I could purchase the 10 AWG brand PV cable compatible with the roof panels, then run the cable in conduit (either pvc or metal) ; DC disconnect shut down switch at the roof ; DC disconnect breaker just prior to going to outside unit ; then that final run, cut off the PV brand terminals compatible with the panels and crimp on these provided MC4 terminals compatible with the unit….thus, the MC4 terminals will be in accord with their instructions at both ends of the run.

IMG_2388.jpeg
 
Cptx said:
Thank you for the feedback; I was unaware regarding the 10awg requirement in solar DC PV cables while running through the house. Easy change to my purchasing list.

The only way I could avoid the attic would be to run the wires off the roof, over the gutters and then pvc conduit all the way around to the north side in 3/4 pvc conduit. I actually like this idea a lot as cosmetics/aesthetics are low on my goal/appreciation list. I know my wife thinks otherwise and I would worry more about squirrels and wiring shenanigans going this route.

Thanks again.
Click to expand...
That’s pretty much what I want to do because I don’t want to route through roof and walls. PVC conduit would keep out water and critters. in my case, I think I can tuck the conduit into a gable corner where it’s out of sight as much as possible. I’m thinking of punching through to basement right above the foundation, then down the wall to a breaker. I’m not planning on conduit once inside the basement. Is that a must? Interested in learning more about your plan.
 
Marine359. Contact your local AHJ (building inspector) and ask them about the wires inside the house.

That way you’ll get a solid answer, rather than opinions?

Start with a phone call followed by an email confirming what the AHJ said. Keep the email in case you ever need to deal with your insurance company or another inspector.
 
DC circuit needs to be in conduit or cable after exiting array. DC circuits also need to be in metal conduit within the building. Solar is allowed to use FMC or MC within building with extra protection or big enough conduit size to be strong enough to not need it.

Need to comply with the solar specific rules in 690 as well as the general rules in 3xx.

Digital Codes

ICC Digital Codes is the largest provider of model codes, custom codes and standards used worldwide to construct safe, sustainable, affordable and resilient structures.
codes.iccsafe.org codes.iccsafe.org
 
I found some flexible 1” aluminum conduit for a good price on Amazon….think I’ll be able to avoid making 90 degree elbows with this.

IMG_2440.jpeg
 
I believe with 1” you can avoid extra protection requirements, but it’s in the code sections I pasted above. And I’ve used flex for exactly the reason of getting out of doing complex EMT bends beyond my scrub DIY skill set.
 
metal clad cable absolutely IS permitted to be used in attic spaces.

flexible conduit is unlikely to be allowed. I don't know and won't answer for it. just go with MC cable properly sized.

make sure you account for temperature derating in your cabling size

look over the FAQs in my signature for guidance
 
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