Would this violate any NEC provisions?

Joe.B

Joe.B

Senior Member
Location
Myrtletown Ca
Occupation
Building Inspector
Someone asked me if these are allowed and my first gut-reaction was "NO!!!!" but I'm not sure I can back that up with anything other than 110.3(C) Listing.

They responded "so, if it's listed by a qualified testing laboratory I can use it?" I told them I needed a day or two to research this and I'll get back to them.

I can't imagine this is a listed device, but if it is, is this really okay???

 
That photo-shopped cord is a crime against bad forgeries, never mind that I see no inverter to create 120v, or that the exposed metal plugs are an electrocution hazard.
 
This violates a section in article 705 that requires a dedicated disconnect for interconnected power sources. The section doesn't actually say 'no loads on the same disconnect' but if you know the history you understand that is the intent.

Some of these products incorporate installation of a CT on the circuit so that the total current drawn on the circuit doesn't exceed the circuit ampacity. But of course that defeats the point of it being plug and play. I gather that in parts of Europe they've decided they just don't care as long as the power stays below 500W or something like that. But in this country anyone selling that is dancing around it being a code violation. Also probably a violation of your utility's rules.
 
ModbusMan said:
That photo-shopped cord is a crime against bad forgeries, never mind that I see no inverter to create 120v, or that the exposed metal plugs are an electrocution hazard.
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I guess I assumed that it had a micro-inverter as part of the panel. I also assumed that the micro-inverter would have rapid-shutdown built in. We all know what assumptions do though so....
 
jaggedben said:
This violates a section in article 705 that requires a dedicated disconnect for interconnected power sources.
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Copy that, I was looking at that too, 2022 CEC 705.20, correct? While I agree with the intent, I want to be ready for all arguments. 705.20 lists conditions (1-8) and the wording implies that it has to comply with all of them. If (and that's a big if) the device were listed, and the listing identified the cord as the disconnect, wouldn't that qualify as satisfying all eight conditions?? The code has precedence for this, see 422.23.
 
While a cord and plug "can be" a disconnecting means. the set up as shown can not be used in the direction it is pictured. I see it as no different than a suicide cord on a generator as the supply is from the solar side and the plug end is exposed terminals and shock hazard. There is no indication of a rapid shut down so the cord end would be energized so long as sunlight present. There are likely other actually codified issues that I haven't looked up.
 
Fred B said:
While a cord and plug "can be" a disconnecting means. the set up as shown can not be used in the direction it is pictured. I see it as no different than a suicide cord on a generator as the supply is from the solar side and the plug end is exposed terminals and shock hazard. There is no indication of a rapid shut down so the cord end would be energized so long as sunlight present. There are likely other actually codified issues that I haven't looked up.
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I feel exactly the same. Hoping to find as many specific code citations as possible. I'm trying not to be that guy that says "because I said so". Also, since there's a good chance they're going to buy it anyways (or maybe they already have) I want to have written evidence that I legitimately denied it.
 
The section I referred to in my previous post is 705.12(A) in the 2020 NEC, but apparently that language does not appear in 2023. However under 2023 I would scrutinize whether the item you linked to complies with 705.20(1)(d?) and I would also argue it probably doesn't comply with 705.30(A) and likely (D) if the breaker is an AFCI or GFCI.

Also the utility interconnection issue stands outside of anything in the NEC.

The bottom line is the people selling these systems are trying to skirt various rules.
 
Joe.B said:
I guess I assumed that it had a micro-inverter as part of the panel. I also assumed that the micro-inverter would have rapid-shutdown built in. We all know what assumptions do though so....
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If you scroll over the additional images one of them is of the inverter that will support two of those panels.

Correction supports 4 panels.
 
You can't feed a multi outlet branch circuit from 2 sources like that, the 12 or 14AWG conductors would no longer be protected.
 
winnie said:
Apparently this sort of system is now legal in Utah:

News report:
cleantechnica.com

Power To The People: Plug-In Solar Now Legal In Utah Homes - CleanTechnica

New legislation in Utah introduces a new category for small, portable solar generation devices, allowing residents to integrate plug-in solar systems into their homes more easily.
cleantechnica.com cleantechnica.com

Actual legislation:

HB0340

le.utah.gov le.utah.gov
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This looks like it simply set up the framework for the application of such but without an actual product being available or other safety concerns being addressed, leaving it to the NEC to develop requirements to make such possible (maybe). More of a limitation on the POCO to set limits to a potential device being used or charging for such. This would be likely several years out as the 2026 is already mostly done and no new additions would be admitted to my understanding, so the earliest it could be implemented is in the 2029 code cycle.

This Utah legislation looks to be adding a requirement for rapid shutdown that was not on the OP listing.
 
If the original product has a typical line interactive micro inverter, would that qualify as 'rapid shutdown'? If you lose mains supply, doesn't the inverter have to shut down for lack of 'excitation'?
 
It uses an NEP microinverter, the BDM-600, and while the microinverter is UL listed using a pigtail with a plug to plug it into the wall is not an installation option in the manual. So this installation is not covered by the UL listing making it an unlisted application. As long as your AHJ allows unlisted PV equipment you are good to go. Or you can pay a few grand for a field evaluation. No idea what modules they are using or if they are UL listed. These type of systems have come and gone for decades. I see them pop up and then the company goes out of business.
 
winnie said:
If the original product has a typical line interactive micro inverter, would that qualify as 'rapid shutdown'? If you lose mains supply, doesn't the inverter have to shut down for lack of 'excitation'?
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and of course would make plug pins not live if it comes unplugged.

This is not something electrical professionals would be installing, but just like a toaster doesn't exactly need a professional to come plug it in nor would it normally require permit or inspection.

If someone were to purchase several of these hoping to have minimal or even credit billing, it likely comes back to bite them somehow. Many utilities don't want you to have a negative billing on a normal basis without prior contracts in place, plus they may have overloaded branch circuit wiring as has been mentioned. Though if you only have the 640 watts on one branch circuit that probably isn't too likely - bigger problem may be if you have it plugged into a $1.50 receptacle vs a higher grade receptacle.
 
pv_n00b said:
It uses an NEP microinverter, the BDM-600, and while the microinverter is UL listed using a pigtail with a plug to plug it into the wall is not an installation option in the manual. So this installation is not covered by the UL listing making it an unlisted application. ...
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I also noticed they seemingly cropped out the part of their adapter plug that shows the male-male 'suicide' cord.
 
Also it should be noted that many(most?) utility meters will count up regardless of which way the energy is flowing (unless you have an older mechanical one). The use of any PV system without the proper utility meter, would need to be coordinated with your base load so that you aren't paying for the electricity you are sending back to the grid.
 
jaggedben said:
I also noticed they seemingly cropped out the part of their adapter plug that shows the male-male 'suicide' cord.
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That cord would have an MC4 connector on it to interface with the microinverter, so it would not be a suicide cord. The remaining portion of the mostly cropped out end is consistent with that.

Cheers, Wayne
 
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