[RE-wrenches] Rapid Shutdown Again?

cwarfel cwarfel at entech-engineering.com
Tue Aug 28 08:50:21 EDT 2018


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, cwarfel at 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

EEI logo <http://entech-engineering.com>
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