Re: [RE-wrenches] Fwd: Re: Rapid Shutdown and January 1 2019 option?

[cwarfel]

Thanks Rebekah, At this time, I feel like we are stranded on one option 
that used to be very popular with my customers.  Unlike most of the 
mainland, 95% of our customers want batteries. Right now, we are only 
going to do ground mounted dc coupled until we have a chance to evaluate 
the Outback system. The combiner box is large and that doesn't excite 
some people. Chris



On 7/6/2018 8:23 PM, Rebekah Hren wrote:

Hi Ray and Dan and Chris, etc,

I agree with a lot of what you are saying, don't get me wrong...I have 
an off-grid house too and I've been worrying about how module level 
shutdown will be implemented and what it means for reliability and 
cost, especially dc-coupled battery-based systems that really don't 
have or need MLPE.


I'm working on article for the Sept/Oct Homepower about rapid shutdown 
and one the things I've been excited to learn about is the new Sunspec 
alliance power line communication protocol 
 
for receivers and transmitters for RS. As Ray mentioned Midnite is 
already selling their SOB 
 
(er, haha). And Tigo just got their cheapest RS MLPE option the TSF-F 
UL  
listed. What's cool is the devices are inverter-agnostic, and don't 
need another conductor for data or power running to them. But as Ray 
also said, they aren't working with charge controllers, yet.


So I do think there is some good news on the horizon! From the way the 
2020 NEC first draft is written, I don't perceive any chance of the 
690.12 rules really changing drastically. But something else that may 
change the products we can use to meet the requirements is a new UL 
standard that is being worked on- UL 3741 PV Hazard control. I don't 
know much about it, but here is a list of the people 
 who 
are on the Standards Technical Panel. I think a few of them are on 
this listserv so maybe one of them will give us an update!


Best,
Rebekah



On Fri, Jul 6, 2018 at 4:39 PM Ray > wrote:





 Forwarded Message 
Subject:Re: [RE-wrenches] Rapid Shutdown and January 1 2019 option?
Date:   Fri, 6 Jul 2018 16:37:47 -0600
From:   Ray  
To: Rebekah Hren 




Hi Rebekah;

I very much appreciated your previous posts on this. Yes, we do
not need to disconnect the inverter and battery per previous
interpretations.  However, the RS system can and will trip for a
variety of reasons, which disconnects the charging system.  It
might take a couple of days to discharge the batteries, but the
results are the same: rotten meat in the fridge and a dead
battery. If no one is home, thousands of dollars of battery could
be ruined in a matter of weeks, if its Gel or AGM.

If we get to a point where all the modules have shut down built
in, and the Controllers also have built in disconnect so their
capacitors don't back feed, then it won't be so hard to comply
with 690.12.  In the mean time though, off grid should be given a
clear exemption based on array size and Voc of the array.  We are
often only wiring 2 modules in series, so we are already well
below 100 v.   Rules designed for 600 v arrays should not
unilaterally apply to everyone, just as 600 VAC rules don't all
apply to 120 vac residential.  There are numerous exemptions for
lower voltage AC situations, we are just asking that the same
thinking be applied to PV.

Ray Walters
Remote Solar
303 505-8760

On 7/6/18 2:57 PM, Rebekah Hren wrote:

I believe there was a big improvement for off-grid systems as
relates to RS in the 2017 NEC - the diagrams in 690.1(b) all show
the PV system disconnect clearly now.  If you check out the
diagrams you can see that energy storage/battery circuits,
including the battery-based inverter whether AC or DC coupled,
are outside the PV system boundary, thus not PV system circuits,
thus not subject to RS.

Also, the NEC 2020 1st draft report has been published

,
so get your comments submitted!

Rebekah Hren
Member, NEC CMP-4

On Fri, Jul 6, 2018 at 2:22 PM Dan Fink mailto:danbo...@gmail.com>> wrote:

I agree with you, Ray, as a purely off-grid solar installer
and troubleshooter. I think all that was accomplished in NEC
2017 on this issue is that non-habitable structures, like the
common off-grid 'power shed' don't need 690.12 RS an

Re: [RE-wrenches] Fwd: Re: Rapid Shutdown and January 1 2019 option?

[Rebekah Hren]

Hi Ray and Dan and Chris, etc,

I agree with a lot of what you are saying, don't get me wrong...I have an
off-grid house too and I've been worrying about how module level shutdown
will be implemented and what it means for reliability and cost, especially
dc-coupled battery-based systems that really don't have or need MLPE.

I'm working on article for the Sept/Oct Homepower about rapid shutdown and
one the things I've been excited to learn about is the new Sunspec
alliance power
line communication protocol

for receivers and transmitters for RS. As Ray mentioned Midnite is already
selling their SOB

(er, haha). And Tigo just got their cheapest RS MLPE option the TSF-F UL
 listed.
What's cool is the devices are inverter-agnostic, and don't need another
conductor for data or power running to them. But as Ray also said, they
aren't working with charge controllers, yet.

So I do think there is some good news on the horizon! From the way the 2020
NEC first draft is written, I don't perceive any chance of the 690.12 rules
really changing drastically. But something else that may change the
products we can use to meet the requirements is a new UL standard that is
being worked on- UL 3741 PV Hazard control. I don't know much about it, but
here is a list of the people
 who
are on the Standards Technical Panel. I think a few of them are on this
listserv so maybe one of them will give us an update!

Best,
Rebekah



On Fri, Jul 6, 2018 at 4:39 PM Ray  wrote:

>
>
>
>  Forwarded Message 
> Subject: Re: [RE-wrenches] Rapid Shutdown and January 1 2019 option?
> Date: Fri, 6 Jul 2018 16:37:47 -0600
> From: Ray  
> To: Rebekah Hren  
>
> Hi Rebekah;
>
> I very much appreciated your previous posts on this. Yes, we do not need
> to disconnect the inverter and battery per previous interpretations.
> However, the RS system can and will trip for a variety of reasons, which
> disconnects the charging system.  It might take a couple of days to
> discharge the batteries, but the results are the same: rotten meat in the
> fridge and a dead battery.  If no one is home, thousands of dollars of
> battery could be ruined in a matter of weeks, if its Gel or AGM.
>
> If we get to a point where all the modules have shut down built in, and
> the Controllers also have built in disconnect so their capacitors don't
> back feed, then it won't be so hard to comply with 690.12.  In the mean
> time though, off grid should be given a clear exemption based on array size
> and Voc of the array.  We are often only wiring 2 modules in series, so we
> are already well below 100 v.   Rules designed for 600 v arrays should not
> unilaterally apply to everyone, just as 600 VAC rules don't all apply to
> 120 vac residential.  There are numerous exemptions for lower voltage AC
> situations, we are just asking that the same thinking be applied to PV.
>
> Ray Walters
> Remote Solar
> 303 505-8760
>
> On 7/6/18 2:57 PM, Rebekah Hren wrote:
>
> I believe there was a big improvement for off-grid systems as relates to
> RS in the 2017 NEC - the diagrams in 690.1(b) all show the PV system
> disconnect clearly now.  If you check out the diagrams you can see that
> energy storage/battery circuits, including the battery-based inverter
> whether AC or DC coupled, are outside the PV system boundary, thus not PV
> system circuits, thus not subject to RS.
>
> Also, the NEC 2020 1st draft report has been published
> ,
> so get your comments submitted!
>
> Rebekah Hren
> Member, NEC CMP-4
>
> On Fri, Jul 6, 2018 at 2:22 PM Dan Fink  wrote:
>
>> I agree with you, Ray, as a purely off-grid solar installer and
>> troubleshooter. I think all that was accomplished in NEC 2017 on this issue
>> is that non-habitable structures, like the common off-grid 'power shed'
>> don't need 690.12 RS anymore.
>>
>> Dan Fink
>> Professor of Solar Energy Technology, Ecotech Institute
>> IREC Certified Instructor™ for:
>> ~ PV Installation Professional
>> ~ Small Wind Installer
>> Executive Director, Buckville Energy
>> NABCEP Registered Continuing Education Providers™
>> NABCEP Associate
>>
>> 970.672.4342
>>
>>
>>
>> On Fri, Jul 6, 2018 at 11:32 AM, Ray  wrote:
>>
>>> Midnite has some string level and module level 690.12 disconnects that
>>> wire in like an optimizer or micro inverter, so those should be able to
>>> meet the 2019 requirements.  However beware:  they as of yet still don't
>>> have a reasonable disconnect system to disconnect the charge controller
>>> which has cap

[RE-wrenches] Fwd: Re: Rapid Shutdown and January 1 2019 option?

[Ray]

 Forwarded Message 
Subject:Re: [RE-wrenches] Rapid Shutdown and January 1 2019 option?
Date:   Fri, 6 Jul 2018 16:37:47 -0600
From:   Ray 
To: Rebekah Hren 



Hi Rebekah;

I very much appreciated your previous posts on this. Yes, we do not need 
to disconnect the inverter and battery per previous interpretations.  
However, the RS system can and will trip for a variety of reasons, which 
disconnects the charging system.  It might take a couple of days to 
discharge the batteries, but the results are the same: rotten meat in 
the fridge and a dead battery.  If no one is home, thousands of dollars 
of battery could be ruined in a matter of weeks, if its Gel or AGM.


If we get to a point where all the modules have shut down built in, and 
the Controllers also have built in disconnect so their capacitors don't 
back feed, then it won't be so hard to comply with 690.12.  In the mean 
time though, off grid should be given a clear exemption based on array 
size and Voc of the array.  We are often only wiring 2 modules in 
series, so we are already well below 100 v.   Rules designed for 600 v 
arrays should not unilaterally apply to everyone, just as 600 VAC rules 
don't all apply to 120 vac residential.  There are numerous exemptions 
for lower voltage AC situations, we are just asking that the same 
thinking be applied to PV.


Ray Walters
Remote Solar
303 505-8760

On 7/6/18 2:57 PM, Rebekah Hren wrote:
I believe there was a big improvement for off-grid systems as relates 
to RS in the 2017 NEC - the diagrams in 690.1(b) all show the PV 
system disconnect clearly now.  If you check out the diagrams you can 
see that energy storage/battery circuits, including the battery-based 
inverter whether AC or DC coupled, are outside the PV system boundary, 
thus not PV system circuits, thus not subject to RS.


Also, the NEC 2020 1st draft report has been published 
, 
so get your comments submitted!


Rebekah Hren
Member, NEC CMP-4

On Fri, Jul 6, 2018 at 2:22 PM Dan Fink > wrote:


I agree with you, Ray, as a purely off-grid solar installer and
troubleshooter. I think all that was accomplished in NEC 2017 on
this issue is that non-habitable structures, like the common
off-grid 'power shed' don't need 690.12 RS anymore.

Dan Fink
Professor of Solar Energy Technology, Ecotech Institute
IREC Certified Instructor™ for:
~ PV Installation Professional
~ Small Wind Installer
Executive Director, Buckville Energy
NABCEP Registered Continuing Education Providers™
NABCEP Associate

970.672.4342


On Fri, Jul 6, 2018 at 11:32 AM, Ray mailto:r...@solarray.com>> wrote:

Midnite has some string level and module level 690.12
disconnects that wire in like an optimizer or micro inverter,
so those should be able to meet the 2019 requirements. 
However beware:  they as of yet still don't have a reasonable
disconnect system to disconnect the charge controller which
has capacitors that back feed the PV line for up to 90
seconds.  They have a DC GFI breaker with remote trip
capability but it takes 4 spaces, so with multiple charge
controllers it turns into a wiring mess really fast.

I actually wired in some 60 amp rated diodes on one system to
get it to pass inspection; what a joke, going back to 1980s
equipment to pass 2017 code.    690.12 is an absolute
nightmare for small off grid.  There really should be some
exemptions for small arrays (under 3 kW) and under 100 vdc.
Fire fighters are not going to get there till the structure is
down anyway,  Response times are up to an hour for remote
locations with volunteer fire departments.  Its not like in
town at all; no one is going to go on the roof on an off grid
fire.

On the flip side, there are real dangers created by nuisance
tripping of 690.12 equipment.  Again, on grid it's a mere
inconvenience, but off grid it could mean spoiled food, frozen
water lines, shut down heating systems in subzero
temperatures, and for the elderly: loss of their breathing
machines.  I've already had a 74 year old customer climbing on
their roof multiple times to reset the Rapid shutdown
equipment after nuisance trips. Are we going to wait until we
get someone killed in the name of "Safety" before we fix this?

Ray Walters
Remote Solar
303 505-8760

On 7/6/18 9:55 AM, cwarfel wrote:


I am wondering about the experience installers have with a DC
coupled multimode system design that will comply after
January 1 with what I feel is the biggest mistake/poorly
guided part of NEC 2017 690,