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diy solar

diy solar

conduit planning

doc3g

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Joined
Oct 9, 2024
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76
Location
Texas
Originally, I planned to penetrate the roof with an EZ solar JB-1.2 or similar junction box and run Romex across the attic and down the wall to the main load center. After the AHJ required me to get electrical/structural PE stamps, I modified the plans to include a visible lockable labeled disconnect and a combiner box (load center on diagram) and added that the wiring would be in a 3/4" EMT conduit.

Off the top of my head I thought I'd just run the conduit across the roof and down the side of the house. However, I'm realizing that A) that may be far more difficult that I originally planned due to the need to get around the gutters and B) that it's probably going to be ugly (less of a concern).

So, now I'm wondering if I can still stay true to the plan (so that it passes inspection) but penetrate the roof at the junction box and just run the conduit inside the attic? Is there anything about the attached diagram indicating that the conduit is outside rather than inside?
 

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Conduit is not required, just use MC cable for the internal run from the proper Jbox that penetrants the roof to your load center. If you haven't worked before with this, make sure you use the anti short insulator at the ends.

So, I'm unable to make any changes to the plan set now that it has been stamped (at least not without paying for a new stamp) and the solar designer drew up the plans with the 3/4" conduit. Currently, the submitted plan is in the "plan review" stage w/ AHJ which is nearly 3 weeks just to get a permit. I'll be honest, despite owning homes for the past 25 years I've never personally gotten a permit to do any work to my own home, so I'm not unsure if it's allowable to make a code compliant change to the plans you submitted (but I assume to pass inspection that the final product needs to match the submitted plan 100%)
 
Unless you have worked with conduit before, its not really a good option for a home-owner, there are also differences with running external and internal with connections and you will at minimum need the benders and debur tools and wire pull tools which to this day I'm still not great with getting the bends exactly right and I have a couple of years working with it. 3/4 is much harder to work with as well than 1/2. Tools needed will cost close to a re-stamp fee.
 
I'm fine w/ running the conduit, I just was curious if the solar plan in the original post somehow indicated if it was internal or external. I've run conduit before, just never off a roof and over a gutter. All of the pictures I've look at reduce the curb appeal of the house, so I'm trying to ensure that if I run the conduit through the attic that I can still be aligned w/ my submitted plan.
 
I am pondering the same thing with my 6 panels I want to install for my EG4 heat pump, so I am curious how your conduit run turns out. Please post updates when you get it worked out and pass inspection.

I am kind of curious about what I think Q-Dog was asking. Do you not have a rapid shutdown location marked on your plans ? I would think that would be an automatic fail. Just guessing here.
 
I am pondering the same thing with my 6 panels I want to install for my EG4 heat pump, so I am curious how your conduit run turns out. Please post updates when you get it worked out and pass inspection.

I am kind of curious about what I think Q-Dog was asking. Do you not have a rapid shutdown location marked on your plans ? I would think that would be an automatic fail. Just guessing here.

The Hoymiles microinverters (as with most microinverters) are already rapid shutdown compliant at the module level.
 
Right on the module electronics, but I guess what we were thinking is that the diagram does not show a rapid shutdown button outside close to the service entrance. The micro inverters would certainly shutdown if grid is lost, but I think they want that button so the fire dept can be sure everything is off if called out for a fire. So that is all I was thinking, but it sounds like you have it figured out.
 
Right on the module electronics, but I guess what we were thinking is that the diagram does not show a rapid shutdown button outside close to the service entrance. The micro inverters would certainly shutdown if grid is lost, but I think they want that button so the fire dept can be sure everything is off if called out for a fire. So that is all I was thinking, but it sounds like you have it figured out.

My best understanding is that NEC 690.12 relates to ensuring high-voltage conductors are not present when the grid is off. Hence, as long as there is an access point to de-energize the grid (already exists on the utility side, and the current setup creates 2 additional states to de-energize) then the microinverters in essence are turning on their own RSD switch.

Contrast this with a typical string inverter where, even if you throw the switch in the main service panel or cut power at the road, the main strings are still cranking out high voltage throughout the conductor runs. This is what creates the need for the RSD button on string inverters.
 
Micro inverters are the code compliant rapid shutdown solution and there is no shutdown button required, all that is required is the accessible ( and properly marked / labeled AC disconnect.
 

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