I like your solutions to this. Just sticking to rapid shutdown and not the fire code, I think a lot of the problems with 690.12 could be reduced if the maximum string voltage was 150 or even 250.  It reduces the ampacity on a roof for a given power and I feel that is more of a danger than array voltage that the Firefighters are highly likely to avoid.

I still cannot get Outback Power to provide a corrected installation manual or a start up procedure on the RSI/ICS equipment. Two plus months and all I get are repeated vague or incorrect information. One expert at OB said that they really didn't deal much with Rapid Shutdown............

I cannot install any more Outback on roofs at this time.

I'll see if it is ok to provide a link to an online petition to change 690.12.


Chris



On 8/27/2018 2:13 PM, Ray wrote:

HI Chris;

As with all things bureaucratic,  good intentions can go awry when actually implemented.  Years ago, I was one of the wrenches pushing for some form of disconnect closer to the power source, or the PV array.  I had no idea it would come back to bite us small off grid folks so hard, though.  I'm not quite for scrapping all of 690.12, but I do think it needs some serious work. /In or on the building/ needs to be defined more clearly as 'on the roof'.  Ground mounts need a clearer exemption. The PV disconnect needs to be clearly defined and also clearly stated that the Rapid disconnect system stops there.  The time limit needs to be bumped up to 90 seconds: no one is going to throw the switch and be hacking on the roof that fast.  The array voltage should be 150 vdc, so that lower voltage off grid systems could be exempt, and I really think 690.12 should only apply to larger arrays (over 10kW) that have long exposed runs of conduit (over 10 yards) or that cover more than a certain percentage of the total roof area.  If an array covers one face of the garage it should be exempt, and if it covers half the total roof, then it should have Rapid disconnect, for instance.  We need to be sensible, do the fire fighters have a good spot to cut and vent the roof without electrical hazards or not?

Its interesting how article 690 has morphed from being almost entirely oriented towards off grid in 99 and 02, to now off grid is barely even considered.  Just look at the lack of thought when they wrote the definitions for /DC to DC Converters/. The solar industry has been ready and willing to be thrown under the bus at every turn.  I think its about time we started advocating for our own self interests like all the other parties involved.  This also means that us off grid folks need to be properly represented, and off grid considered with all code changes.  I think DC coupled PV should have its own section and be separated from AC coupled PV.  The systems are so different that it doesn't make sense to throw them into the same section. The emergence of article 706 is a step in the right direction.

Ray Walters
Remote Solar
303 505-8760
On 8/23/18 5:31 PM, cwar...@entech-engineering.com wrote:

I think Rapid Shutdown should be scrapped professionally and personally.  It was ill conceived and ill written.  Anyone willing to join me in a petition to CMP 44 and the like, contact me off list.

To your question directly, you have a ground mounted system and you are not subject to 690.12 unless your conductors are "in or on building" which i cannot seem to find what that actually means. Exempted are buildings that are isolated only for the PV system This is a big win for installers as almost everyone installs systems like this.......   Right.    They used to have a dimension to this, but I guess that gave installers too much information. This is a stupid Code addition for roof mounted pv systems, disguised as protecting Firefighters, but not doing so in reality. The NEC looks politically compromised by consultants and manufacturers who too advantage of this fear mongering. No other country with a pv industry has historically done this. Why are installers not up in arms about this?

This is the NEC reference.

690.12 Rapid Shutdown of PV Systems on Buildings. PV system circuits installed on or in buildings shall include a rapid shutdown function to reduce shock hazard for emergency responders in accordance with 690.12(A) through (D).

If your system is ground mounted, you are outside the "altruistic" intent of 690.12 of protecting Firefighters. Put a initiation device disconnect switch at the array.  Any supporters of RS should chime in with the support of 690.12 and add clarity and guidance to those of us who actually install systems and have to deal with this baloney.  690.12 has caused more problems for multimode systems than any tariffs, which are bad enough. I don' think the industry needs any more "safe design and installation" assistance from the CMPs involved with this issue.

Chris Warfel






On 2018-08-23 00:31, Ray wrote:

Greetings fellow wrenches;

I know we have beat this many times but I once again have not been able to resolve the contradictory information in 690 in regards to implementing 690.12.  As Rebekah Hren pointed out before, the diagrams shown in Figure 690.1(b) show that the /PV System DC Circuit/ stops at the /PV Disconnect/.  Note 2 says specifically the '/PV Disconnect separates the PV system from all other systems/'. But then in the definitions in 690.2 on the next page, the new definition of a /P//V System DC Circuit/ says that it includes DC to DC converter output circuits. (which are Solar Edge module level controls, but could be interpreted as a MPPT battery charge Controller?)

Then 690.12 which only applies to '/PV System circuits in or on buildings/', says we have to control conductors more than 3 ft after penetrating the building.

So in my case, I'm looking at a ground mount, and installing an external lockable disconnect on the wall before it goes into the building.  This will officially be the PV Disconnect.  In my interpretation, I should not need to do any Rapid Shutdown, because I've essentially prevented the /PV system/ from ever entering the building at all ( based on the 5th diagram and Note 2)  However, I could see an AHJ claiming I had to do RS all the way to the output side of the charge controller.

If this were true, could I simply apply RS equipment from the PV disconnect to the output of the charge controller, or am I back to module level shutdown for my ground mounted array, or could I build a tiny building that just housed the PV Disconnect and take the exemption for '/buildings with the sole purpose of housing PV system equipment/'?

Essentially the definitions in 690.2 are too broad, and are at odds with the Figure and Notes of 690.1.  They really didn't fix this in the 2017 code for us lowly off gridders. Charge controllers are covered by article 706.23___/Charge Control/_, and NOT by 690.12 at all. IMHO, the charge controller needs to be clearly defined and differentiated from DC to DC converters like Solar Edge's module level DC equipment.

I just want to go back to doing solar designs and installations, and quit acting like an attorney parsing every word of this confusing code language.

--
Ray Walters
Remote Solar
303 505-8760

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--

         Christopher Warfel, PE
       ENTECH Engineering, Inc.
PO Box 871, Block Island, RI 02807
               (401)466-8978

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