Re: [RE-wrenches] Rapid Shutdown Compliance

[drake . chamberlin]

Martin, 


Micro inverters are the safest. Opening a string under load is
dangerous. Having qualified personnel servicing the equipment is
essential. 


My point is that an isolated incident is not statistical data. All
technologies have their hazards. The number of electricians injured by
various causes is significant. From the data I've seen, the number
injured by DC power on PV systems is very small compared to the number
injured by arc flashes from high voltage electrical panels, falls and
other causes. 


A typical residence in the U.S. has a 240 VAC wire connected to the
house that cannot be turned off by the homeowner or the fire department.
With a 10,000 Amp surge from the transformer, it can arc at 2,400,000 W!
A 12 kW PV system could produce ½ of 1% of that amount of power at full
STC production. 


Sometimes this utility feed is run in Service Entrance Cable, which is
code-compliant. No conduit is required. The potential hazards of these
systems are orders of magnitude greater than those of current limited
strings of PV modules. 


Someone must bear the expense of MLPE replacements. We are in a
worldwide carbon crisis now. I believe that making PV as easy, reliable
and inexpensive as possible is of paramount importance. If dangers can
be demonstrated that are out of proportion to other common technologies,
then steps should be taken. So far, this does not appear to be the case.


Drake

---

On 2020-05-11 16:04, Martin Herzfeld wrote:

Drake, I concur with your approach on this item -

1.  Either the shock hazard was reduced by NEC 690.12 with MLPE for the workers too or folks have been qualified persons in accordance with NEC 690.4(C) to recognize and avoid the shock hazard for string inverters. 

2.  Specifically, there's this incident on the list found here: https://www.osha.gov/pls/imis/accidentsearch.accident_detail?id=101927.015   In other words, would this incident have been minimized with the use of MLPE?  

On Wed, May 6, 2020, 5:41 PM  wrote: 


Interestingly enough, the data on the link [1] provided shows accidents from 
gas explosions, falls, health problems and  industrial injuries. None of these 
incidents could have been prevented by module level power electronics. This is 
typical of the data that I've seen so far.

---

On 2020-05-06 17:22, Martin Herzfeld wrote: 

There could be an issue of encouraging MLPE for worker safety? 

1.  This is data involving incidents with workers in the OSHA Fatalities and Catastrophe Investigation Summaries found here: 
https://www.osha.gov/pls/imis/AccidentSearch.search?p_logger=1_description=_Abstract=solar_keywordAll=All=05=05=2002=05=05=2021= 

2.  In the past I've observed an arc fault at the module level with traditional string systems without a listed arc-fault circuit interrupter NEC/CEC 690.11. The function in NEC/CEC 690.12 would be - to reduce the shock hazard - for _emergency responders_ or _firefighters? (NEC 2020)._  However, I've observed thermal events in the panelboard with plans and workmanship issues.  

On the other hand, falls are the #1 reason for incidents in the construction industry.  

All the best, 


Martin Herzfeld, Interstate Renewable Energy Council (IREC) Certified Master 
Trainer (tm) for Photovoltaics (PV) Installation Professional #IREC 10037
Contract Training Provider (CTP)
Adjunct Professor, Energy

California Solar & Electrical Contractor License  #00833782  C46, C10, D56, 
D31, C-7 - Since 2004
Solar, Electrical, Trenching, Pole Installation & Maintenance, Instrumentation

Contract Solar (PV) Technical Inspector - 3rd Party Inspections 
Underwriters Laboratories (UL) Certified PV Installer #17, OSHA 30

OSHA-Authorized Construction Trainer #32-0105338
CompTIA Certified Technical Classroom Trainer (CTT+) #T3NSZCNBBKB4QTQG

* Professional Member, International Association of Electrical Inspectors  
#7035507 - Since 2006
* Accredited and Registered North American Board of Certified Energy 
Practitioners (NABCEP) Continuing Education (CE) Training Provider

On Thu, Apr 30, 2020, 8:29 AM  wrote: 

I would like to see real data on the fire risk of string inverters. Anecdotal problems are not data. 

The industry is definitely heading toward MLPE due to the rapid shutdown requirements. In many cases MLPE makes sense, in other cases it doesn't.  

Systems that are more cost effective and reliable can often be built by using string inverters. 
--- 

On 2020-04-29 22:05, Jason Szumlanski wrote: 


"Rapid Shutdown does not prevent fires."

Not true. If the effect of RS is to steer the market to MLPE, I believe it has a significant impact on reducing fire risk. As one who has watched a DC conductor fire smolder out of control, I am sold on an AC module or microinverter architecture. While RS on a DC array doesn't necessarily reduce fire risk within the array, it still has the potential to reduce severity and spread. Nothing is going to prevent all fires. I get that. We're talking about risk mitigation when it 

Re: [RE-wrenches] Rapid Shutdown Compliance

[Martin Herzfeld]

Drake, I concur with your approach on this item -

1.  Either the shock hazard was reduced by NEC 690.12 with MLPE for the
workers *too* or folks have been qualified persons in accordance with NEC
690.4(C) to recognize and avoid the shock hazard for string inverters.

2.  Specifically, there's this incident on the list found here:
https://www.osha.gov/pls/imis/accidentsearch.accident_detail?id=101927.015
In other words, would this incident have been minimized with the use of
MLPE?

On Wed, May 6, 2020, 5:41 PM  wrote:

> Interestingly enough, the data on the link
> 
>  provided
> shows accidents from gas explosions, falls, health problems and  industrial
> injuries. None of these incidents could have been prevented by module level
> power electronics. This is typical of the data that I've seen so far.
> ---
>
>
>
> On 2020-05-06 17:22, Martin Herzfeld wrote:
>
> There could be an issue of encouraging MLPE for worker safety?
>
> 1.  This is data involving incidents with workers in the OSHA Fatalities
> and Catastrophe Investigation Summaries found here:
>
> https://www.osha.gov/pls/imis/AccidentSearch.search?p_logger=1_description=_Abstract=solar_keywordAll=All=05=05=2002=05=05=2021=
>
> 2.  In the past I've observed an arc fault at the module level with
> traditional string systems without a listed arc-fault circuit interrupter
> NEC/CEC 690.11. The function in NEC/CEC 690.12 would be - to *reduce the
> shock hazard *- for *emergency responders* or *firefighters? (NEC 2020).*
> However, I've observed thermal events in the panelboard with plans and
> workmanship issues.
>
> On the other hand, falls are the #1 reason for incidents in the
> construction industry.
>
> All the best,
>
> Martin Herzfeld, Interstate Renewable Energy Council (IREC) Certified
> Master Trainer ™ for Photovoltaics (PV) Installation Professional #IREC
> 10037
> Contract Training Provider (CTP)
> Adjunct Professor, Energy
>
> California Solar & Electrical Contractor License  #00833782  C46, C10,
> D56, D31, C-7 - Since 2004
> Solar, Electrical, Trenching, Pole Installation & Maintenance,
> Instrumentation
>
> Contract Solar (PV) Technical Inspector - 3rd Party Inspections
> Underwriters Laboratories (UL) Certified PV Installer #17, OSHA 30
> OSHA-Authorized Construction Trainer #32-0105338
> CompTIA Certified Technical Classroom Trainer (CTT+) #T3NSZCNBBKB4QTQG
>
> * Professional Member, International Association of Electrical Inspectors
> #7035507 - Since 2006
> * Accredited and Registered North American Board of Certified Energy
> Practitioners (NABCEP) Continuing Education (CE) Training Provider
>
>
> On Thu, Apr 30, 2020, 8:29 AM 
> wrote:
>
>
> I would like to see real data on the fire risk of string inverters.
> Anecdotal problems are not data.
>
> The industry is definitely heading toward MLPE due to the rapid shutdown
> requirements. In many cases MLPE makes sense, in other cases it doesn't.
>
> Systems that are more cost effective and reliable can often be built by
> using string inverters.
> ---
>
>
>
>
> On 2020-04-29 22:05, Jason Szumlanski wrote:
>
> "Rapid Shutdown does not prevent fires."
>
> Not true. If the effect of RS is to steer the market to MLPE, I believe it
> has a significant impact on reducing fire risk. As one who has watched a DC
> conductor fire smolder out of control, I am sold on an AC module or
> microinverter architecture. While RS on a DC array doesn't necessarily
> reduce fire risk within the array, it still has the potential to reduce
> severity and spread. Nothing is going to prevent all fires. I get that.
> We're talking about risk mitigation when it comes to RS.
>
> As for "dependable string inverters," the one dependable feature is
> failure at least once in the module lifetime, accompanied by a shocking
> repair bill.
>
> I'm not a shiny object following kind of guy, but the writing is on the
> wall. MLPE is the future. Modular, serviceable, disposable if you will.
> Like it or not, Edison is going to lose this battle to Tesla (Tom vs
> Nikola). And I live less than 5 minutes away from Tommy E's winter home in
> Fort Myers, FL. And I "grew up" in the industry living off-grid in DC
> power. But AC distribution wins for safety at various scales.
>
>
>
>
>
>
> On Wed, Apr 29, 2020, 9:42 PM 
> wrote:
>
> Rapid Shutdown does not prevent fires; it was originally drafted to allow
> firefighters to vent a roof without being hindered by energized PV arrays.
> This rule was expanded to include other DC wiring from PV sources.
>
> As for PV safety, I'd like to see some significant, statistical evidence
> that shows there is a major fire danger from PV relative to other sources.
> A fire from a solar array gets a lot more press than one from a gas leak,
> bad wiring or an ash tray emptied into a wastepaper basket.
>
> Large public buildings should have all the protection 

Re: [RE-wrenches] Rapid Shutdown Compliance

[cwarfel]

I live in a small town, so our outreach probably has greater impact. We
have gone to the FD meetings, we tell them about the system types and
definitions, quiz them and follow up.   So, I think depending upon
training, which is not a one shot deal, it can have an impact. They seem
relieved.

On 2020-05-07 11:39, Brian Mehalic wrote:

> I agree: utilize the formal process, ideally with a group of folks.  If you 
> are a SEIA member, get involved in their Codes and Standards process.  The 
> additional directory language you suggest is not likely to be valuable to 
> many first responders without significant training and documentation, and 
> even then is still likely to get "lost" amongst other labels and directories. 
> RS as required now instead focuses on an initiation device(s), so that the 
> device is all responders need to look for - it's up to the installer to 
> specify and put in the correct gear to make RS happen, and the AHJ to verify 
> this.
> 
> Brian Mehalic 
> NABCEP Certified Solar PV Installation Professional(tm) R031508-59 
> National Electrical Code(R) CMP-4 Member 
> (520) 204-6639
> 
> Solar Energy International
> http://www.solarenergy.org 
> 
> SEI Professional Services 
> http://www.seisolarpros.com [1] 
> 
> On Thu, May 7, 2020 at 6:43 AM Christopher Warfel 
>  wrote: 
> 
> I believe Rapid Shutdown was mostly a solution looking for a problem.   The 
> only way I see this becoming "reasonable" is to present "grievances" to the 
> Code Making Panel WITH a solution for their consideration.  Based on 
> experience from being part of an outreach program that taught approximately 
> 10k firefighters over four years, I have asked that they add to the 
> Directory, the language that states what type of solar electric system is on 
> site (Microinverter, dc optimizer, string, multimode, grid isolated) so that 
> First Responders don't have to guess.  I realize this is different than MLPE, 
> but it targets the person who Rapid Shutdown came into being for, and that 
> was the First Responder.   Chris 
> 
> On 5/6/2020 10:37 PM, Ray wrote: 
> 
> Spending more time on the roof, while putting more equipment and parts to 
> meet MLPE, means more trips up the ladder, which increases, not decreases the 
> #1 worker safety danger: Falls.  Please correct me if I have somehow 
> misunderstood this, but MLPE is not making installers safer based on OSHA 
> information provided.   Also after installation, which system is more likely 
> to require workers to return to work on the roof, pulling up modules, trying 
> to find problem equipment?  More connections is More safe?  Really?  I 
> haven't had to climb back up on the roof on any of my older, lower voltage 
> off grid work in almost a decade. 
> 
> Once again, MLPE has its place, (larger systems, multiple subarrays, higher 
> voltage) but we should have sensible exemptions as have been mentioned 
> already.  We are endangering ourselves and our employees needlessly, to 
> comply with 690.12.  
> 
> Ray Walters
> Remote Solar
> 303 505-8760
> 
> On 5/6/20 8:41 PM, drake.chamber...@redwoodalliance.org wrote: 
> 
> Interestingly enough, the data on the link [2] provided shows accidents from 
> gas explosions, falls, health problems and  industrial injuries. None of 
> these incidents could have been prevented by module level power electronics. 
> This is typical of the data that I've seen so far.
> 
> ---
> 
> On 2020-05-06 17:22, Martin Herzfeld wrote: 
> 
> There could be an issue of encouraging MLPE for worker safety? 
> 
> 1.  This is data involving incidents with workers in the OSHA Fatalities and 
> Catastrophe Investigation Summaries found here: 
> https://www.osha.gov/pls/imis/AccidentSearch.search?p_logger=1_description=_Abstract=solar_keywordAll=All=05=05=2002=05=05=2021=
>  
> 
> 2.  In the past I've observed an arc fault at the module level with 
> traditional string systems without a listed arc-fault circuit interrupter 
> NEC/CEC 690.11. The function in NEC/CEC 690.12 would be - to reduce the shock 
> hazard - for _emergency responders_ or _firefighters? (NEC 2020)._  However, 
> I've observed thermal events in the panelboard with plans and workmanship 
> issues.  
> 
> On the other hand, falls are the #1 reason for incidents in the construction 
> industry.  
> 
> All the best, 
> 
> Martin Herzfeld, Interstate Renewable Energy Council (IREC) Certified Master 
> Trainer (tm) for Photovoltaics (PV) Installation Professional #IREC 10037
> Contract Training Provider (CTP)
> Adjunct Professor, Energy
> 
> California Solar & Electrical Contractor License  #00833782  C46, C10, D56, 
> D31, C-7 - Since 2004
> Solar, Electrical, Trenching, Pole Installation & Maintenance, Instrumentation
> 
> Contract Solar (PV) Technical Inspector - 3rd Party Inspections 
> Underwriters Laboratories (UL) Certified PV Installer #17, OSHA 30
> OSHA-Authorized Construction Trainer #32-0105338
> CompTIA Certified Technical Classroom Trainer (CTT+) 

Re: [RE-wrenches] Rapid Shutdown Compliance

[Lones Tuss]

Hello All
OutBack does offer a RSD solutions.
Please see the links below
http://www.outbackpower.com/products/safety-compliance/rapid-shutdown-kits
We also pair up with the FireRaptor RSD product
http://www.outbackpower.com/products/safety-compliance/fireraptor-rapid-shutdown

In addition the FM100 has onboard AFCI
http://www.outbackpower.com/products/charge-controllers/flexmax-100-afci

I hope this helps.
Take Care All




From: RE-wrenches  On Behalf Of 
Jerry Shafer
Sent: Wednesday, April 29, 2020 11:34 PM
To: RE-wrenches 
Subject: Re: [RE-wrenches] Rapid Shutdown Compliance

Wrenches
We are taking two very different issues and mixing them together. RSD and 
Arc-fault are different, arc fault will and does prevent fires, RSD was brought 
out of the need to vent a roof that even with the meter pulled have 500 volts 
and resulted shocks to fire fighters by cutting into roofs or nearby conduite. 
This is fact not conjecture.
Arc fault is a fire preventer but requires nothing on the roof when using 
string level inverters. Now both RSD and arc-fault in off grid increase the 
complexity but the new charge controllers fit the arc and Tigo fixes the RSD 
issues.
I know everyone of you learned to use a smart phone and can now adapt again to 
this new tech, we have to be leaders in this industry and not well you know.
Jerry
NABCEP PV Inspector.
Been in this industry since 1978

On Wed, Apr 29, 2020, 6:57 PM Jay 
mailto:jay.pe...@gmail.com>> wrote:
Hi Drake

I will disagree, there have been many roof top fires.

But regardless we have to do these new regulations and I for one welcome the 
safety.

The main issue is accessing the faulty/suspect component under the module 
possibly requiring removing multiple modules, a slow and expensive process.

My technique is to install the MLPE at the edges of the array, using wire 
extensions. That way at most I have to remove a single module.  And Im working 
on a drop bracket which would allow better cooling and easier access without 
module removal to the MLPE, greatly reducing time to swap.

Jay

Peltz Power.






On Apr 29, 2020, at 7:59 AM, 
drake.chamber...@redwoodalliance.org<mailto:drake.chamber...@redwoodalliance.org>
 wrote:


Clearly, rapid shutdown increases cost and reduces reliability. Given the 
excellent safety record of PV, prior to rapid shutdown being required, it is 
unnecessary. The few anecdotal incidents of PV fires were not enough to justify 
the requirement, especially on smaller systems.

According to a friend who worked for a local installation company that went 
under, a big part of the reason for their failure was the chronic replacement 
of microinverters and optimizers.

What steps can be taken to create some balance in the rapid shutdown 
requirements that are in the NEC?


---




On 2020-04-29 07:27, Sky Sims wrote:
So far rapid shutdown has been a nightmare. It's added a lot of cost for no 
measurable benefit.
Using always off devices like midnight solar and Tigo makes it impossible to 
test open circuit voltages. Which opens the door to tons of problems when 
commissioning systems.
Also we've been trying out midnight Solar's product and have had an absurd 
failure rate. Which means lots of truck rolls and troubleshooting and system 
downtime. They send replacement product but they aren't paying for the lost 
weeks of productivity.
We have Tigo product in hand and are deciding which project to try it on. But 
our big concern about using it is not only the inability to confirm open 
circuit voltage of the strings but also the way panels bypass if the device 
doesn't allow the panel to connect properly. Both of these features are a 
recipe for problems and potential troubleshooting nightmares. The warranty from 
Tigo doesn't cover our expense if the product fails. And that's really what our 
reservations about the product boil down to right now. If we're on a job with 
50 units and one fails, the contractor or the homeowner will be the ones eating 
the expense of finding it and replacing it. There has to be a better option.

Sky Sims
Https://EcologicalSystems.biz


On Apr 28, 2020, at 7:46 PM, Corey Shalanski 
mailto:coreso...@gmail.com>> wrote:
Now that 690.12 of the NEC 2017 has been in effect for several years, I am 
curious how designers and installers are meeting the associated requirements 
with string inverter-based systems (*not* considering microinverters or DC 
optimizers). I am generally a fan of the KISS principle, and as best I can 
determine the Tigo TS4-F device is one of the simplest options currently 
available on the market. What are others finding?

I'd love to hear about favored options for complying with rapid shutdown. Any 
success stories? or better yet, any early failures?

--
Corey Shalanski
Jah Light Solar
Portland, Jamaica
___
List sponsored by Redwood Alliance

List Address: 
RE-wrenches@lists.re-wrenches.org<mailto:RE-wrenches@lists.re-

Re: [RE-wrenches] Rapid Shutdown Compliance

[Brian Mehalic]

I agree: utilize the formal process, ideally with a group of folks.  If you
are a SEIA member, get involved in their Codes and Standards process.  The
additional directory language you suggest is not likely to be valuable to
many first responders without significant training and documentation, and
even then is still likely to get "lost" amongst other labels and
directories. RS as required now instead focuses on an initiation device(s),
so that the device is all responders need to look for - it's up to the
installer to specify and put in the correct gear to make RS happen, and the
AHJ to verify this.

Brian Mehalic
NABCEP Certified Solar PV Installation Professional™ R031508-59
National Electrical Code® CMP-4 Member
(520) 204-6639

Solar Energy International
http://www.solarenergy.org

SEI Professional Services
http://www.seisolarpros.com



On Thu, May 7, 2020 at 6:43 AM Christopher Warfel <
cwar...@entech-engineering.com> wrote:

> I believe Rapid Shutdown was mostly a solution looking for a problem.
> The only way I see this becoming "reasonable" is to present "grievances" to
> the Code Making Panel WITH a solution for their consideration.  Based on
> experience from being part of an outreach program that taught approximately
> 10k firefighters over four years, I have asked that they add to the
> Directory, the language that states what type of solar electric system is
> on site (Microinverter, dc optimizer, string, multimode, grid isolated) so
> that First Responders don't have to guess.  I realize this is different
> than MLPE, but it targets the person who Rapid Shutdown came into being
> for, and that was the First Responder.   Chris
>
>
> On 5/6/2020 10:37 PM, Ray wrote:
>
> Spending more time on the roof, while putting more equipment and parts to
> meet MLPE, means more trips up the ladder, which increases, not decreases
> the #1 worker safety danger: Falls.  Please correct me if I have somehow
> misunderstood this, but MLPE is not making installers safer based on OSHA
> information provided.   Also after installation, which system is more
> likely to require workers to return to work on the roof, pulling up
> modules, trying to find problem equipment?  More connections is More safe?
> Really?  I haven't had to climb back up on the roof on any of my older,
> lower voltage off grid work in almost a decade.
>
> Once again, MLPE has its place, (larger systems, multiple subarrays,
> higher voltage) but we should have sensible exemptions as have been
> mentioned already.  We are endangering ourselves and our employees
> needlessly, to comply with 690.12.
>
> Ray Walters
> Remote Solar
> 303 505-8760
>
> On 5/6/20 8:41 PM, drake.chamber...@redwoodalliance.org wrote:
>
> Interestingly enough, the data on the link
> 
>  provided
> shows accidents from gas explosions, falls, health problems and  industrial
> injuries. None of these incidents could have been prevented by module level
> power electronics. This is typical of the data that I've seen so far.
> ---
>
>
>
> On 2020-05-06 17:22, Martin Herzfeld wrote:
>
> There could be an issue of encouraging MLPE for worker safety?
>
> 1.  This is data involving incidents with workers in the OSHA Fatalities
> and Catastrophe Investigation Summaries found here:
>
> https://www.osha.gov/pls/imis/AccidentSearch.search?p_logger=1_description=_Abstract=solar_keywordAll=All=05=05=2002=05=05=2021=
>
> 2.  In the past I've observed an arc fault at the module level with
> traditional string systems without a listed arc-fault circuit interrupter
> NEC/CEC 690.11. The function in NEC/CEC 690.12 would be - to *reduce the
> shock hazard *- for *emergency responders* or *firefighters? (NEC 2020).*
> However, I've observed thermal events in the panelboard with plans and
> workmanship issues.
>
> On the other hand, falls are the #1 reason for incidents in the
> construction industry.
>
> All the best,
>
> Martin Herzfeld, Interstate Renewable Energy Council (IREC) Certified
> Master Trainer ™ for Photovoltaics (PV) Installation Professional #IREC
> 10037
> Contract Training Provider (CTP)
> Adjunct Professor, Energy
>
> California Solar & Electrical Contractor License  #00833782  C46, C10,
> D56, D31, C-7 - Since 2004
> Solar, Electrical, Trenching, Pole Installation & Maintenance,
> Instrumentation
>
> Contract Solar (PV) Technical Inspector - 3rd Party Inspections
> Underwriters Laboratories (UL) Certified PV Installer #17, OSHA 30
> OSHA-Authorized Construction Trainer #32-0105338
> CompTIA Certified Technical Classroom Trainer (CTT+) #T3NSZCNBBKB4QTQG
>
> * Professional Member, International Association of Electrical Inspectors
> #7035507 - Since 2006
> * Accredited and Registered North American Board of Certified Energy
> Practitioners (NABCEP) Continuing Education (CE) Training Provider
>
>
> On Thu, Apr 30, 2020, 8:29 AM 
> wrote:
>
>

Re: [RE-wrenches] Rapid Shutdown Compliance

[Christopher Warfel]

To change this, we need to recognize we are "fighting City Hall", and I 
doubt the CMP will be motivated to make changes on their own.  Maybe 
this has always been more political than technical, but it seems that 
those who are opposed to the current requirements need to make it known 
through the formal processes. The CMP is required to respond and in that 
response we can learn of their reasons for not accepting any changes, or 
the changes they would be willing to consider.  I just don't see things 
changing otherwise.


On 5/7/2020 10:18 AM, James Jarvis wrote:
If first responders are the point of all the rapid shutdown, there 
needs to be better exemptions. I personally have a 20kW solar array on 
a 100 year old unused barn at my farm. The roof is at 50 degrees slope 
and needs a 60ft boom lift to access. There was significant extra 
expense and effort for the rapid shut down. And there is absolutely 
zero chance that a first responder would do anything other than watch 
the barn burn. And now I have an array that needs a $1,000 piece of 
rental equipment to get to the back of any module.


There is a big difference between the stuff that is in big cities and 
what is in rural and what is in remote locations. For my telecom 
customers in Alaska and Antarctica, what is the point of decreasing 
reliability by putting module level electronics on solar arrays that 
require a multiple hour helicopter flight to get to. That's not 
protecting anybody other than the MLPE manufacturer's profit.



-James Jarvis
APRS World, LLC
+1-507-454-2727
http://www.aprsworld.com/


On Thu, May 7, 2020 at 8:43 AM Christopher Warfel 
> wrote:


I believe Rapid Shutdown was mostly a solution looking for a
problem.   The only way I see this becoming "reasonable" is to
present "grievances" to the Code Making Panel WITH a solution for
their consideration.  Based on experience from being part of an
outreach program that taught approximately 10k firefighters over
four years, I have asked that they add to the Directory, the
language that states what type of solar electric system is on site
(Microinverter, dc optimizer, string, multimode, grid isolated) so
that First Responders don't have to guess.  I realize this is
different than MLPE, but it targets the person who Rapid Shutdown
came into being for, and that was the First Responder.   Chris


On 5/6/2020 10:37 PM, Ray wrote:


Spending more time on the roof, while putting more equipment and
parts to meet MLPE, means more trips up the ladder, which
increases, not decreases the #1 worker safety danger: Falls. 
Please correct me if I have somehow misunderstood this, but MLPE
is not making installers safer based on OSHA information
provided. Also after installation, which system is more likely to
require workers to return to work on the roof, pulling up
modules, trying to find problem equipment?  More connections is
More safe?  Really?  I haven't had to climb back up on the roof
on any of my older, lower voltage off grid work in almost a decade.

Once again, MLPE has its place, (larger systems, multiple
subarrays, higher voltage) but we should have sensible exemptions
as have been mentioned already.  We are endangering ourselves and
our employees needlessly, to comply with 690.12.

Ray Walters
Remote Solar
303 505-8760
On 5/6/20 8:41 PM, drake.chamber...@redwoodalliance.org
 wrote:


Interestingly enough, the data on the link


 provided
shows accidents from gas explosions, falls, health problems and 
industrial injuries. None of these incidents could have been
prevented by module level power electronics. This is typical of
the data that I've seen so far.

---


On 2020-05-06 17:22, Martin Herzfeld wrote:


There could be an issue of encouraging MLPE for worker safety?
1.  This is data involving incidents with workers in the OSHA
Fatalities and Catastrophe Investigation Summaries found here:

https://www.osha.gov/pls/imis/AccidentSearch.search?p_logger=1_description=_Abstract=solar_keywordAll=All=05=05=2002=05=05=2021=
2.  In the past I've observed an arc fault at the module level
with traditional string systems without a listed arc-fault
circuit interrupter NEC/CEC 690.11. The function in NEC/CEC
690.12 would be - to _reduce the shock hazard _- for /emergency
responders/ or /firefighters? (NEC 2020)./  However, I've
observed thermal events in the panelboard with plans and
workmanship issues.
On the other hand, falls are the #1 reason for incidents in the
construction industry.
All the best,

Martin Herzfeld, Interstate Renewable Energy Council (IREC)
 

Re: [RE-wrenches] Rapid Shutdown Compliance

[James Jarvis]

If first responders are the point of all the rapid shutdown, there needs to
be better exemptions. I personally have a 20kW solar array on a 100 year
old unused barn at my farm. The roof is at 50 degrees slope and needs a
60ft boom lift to access. There was significant extra expense and effort
for the rapid shut down. And there is absolutely zero chance that a first
responder would do anything other than watch the barn burn. And now I have
an array that needs a $1,000 piece of rental equipment to get to the back
of any module.

There is a big difference between the stuff that is in big cities and what
is in rural and what is in remote locations. For my telecom customers in
Alaska and Antarctica, what is the point of decreasing reliability by
putting module level electronics on solar arrays that require a multiple
hour helicopter flight to get to. That's not protecting anybody other than
the MLPE manufacturer's profit.


-James Jarvis
APRS World, LLC
+1-507-454-2727
http://www.aprsworld.com/


On Thu, May 7, 2020 at 8:43 AM Christopher Warfel <
cwar...@entech-engineering.com> wrote:

> I believe Rapid Shutdown was mostly a solution looking for a problem.
> The only way I see this becoming "reasonable" is to present "grievances" to
> the Code Making Panel WITH a solution for their consideration.  Based on
> experience from being part of an outreach program that taught approximately
> 10k firefighters over four years, I have asked that they add to the
> Directory, the language that states what type of solar electric system is
> on site (Microinverter, dc optimizer, string, multimode, grid isolated) so
> that First Responders don't have to guess.  I realize this is different
> than MLPE, but it targets the person who Rapid Shutdown came into being
> for, and that was the First Responder.   Chris
>
>
> On 5/6/2020 10:37 PM, Ray wrote:
>
> Spending more time on the roof, while putting more equipment and parts to
> meet MLPE, means more trips up the ladder, which increases, not decreases
> the #1 worker safety danger: Falls.  Please correct me if I have somehow
> misunderstood this, but MLPE is not making installers safer based on OSHA
> information provided.   Also after installation, which system is more
> likely to require workers to return to work on the roof, pulling up
> modules, trying to find problem equipment?  More connections is More safe?
> Really?  I haven't had to climb back up on the roof on any of my older,
> lower voltage off grid work in almost a decade.
>
> Once again, MLPE has its place, (larger systems, multiple subarrays,
> higher voltage) but we should have sensible exemptions as have been
> mentioned already.  We are endangering ourselves and our employees
> needlessly, to comply with 690.12.
>
> Ray Walters
> Remote Solar
> 303 505-8760
>
> On 5/6/20 8:41 PM, drake.chamber...@redwoodalliance.org wrote:
>
> Interestingly enough, the data on the link
> 
>  provided
> shows accidents from gas explosions, falls, health problems and  industrial
> injuries. None of these incidents could have been prevented by module level
> power electronics. This is typical of the data that I've seen so far.
> ---
>
>
>
> On 2020-05-06 17:22, Martin Herzfeld wrote:
>
> There could be an issue of encouraging MLPE for worker safety?
>
> 1.  This is data involving incidents with workers in the OSHA Fatalities
> and Catastrophe Investigation Summaries found here:
>
> https://www.osha.gov/pls/imis/AccidentSearch.search?p_logger=1_description=_Abstract=solar_keywordAll=All=05=05=2002=05=05=2021=
>
> 2.  In the past I've observed an arc fault at the module level with
> traditional string systems without a listed arc-fault circuit interrupter
> NEC/CEC 690.11. The function in NEC/CEC 690.12 would be - to *reduce the
> shock hazard *- for *emergency responders* or *firefighters? (NEC 2020).*
> However, I've observed thermal events in the panelboard with plans and
> workmanship issues.
>
> On the other hand, falls are the #1 reason for incidents in the
> construction industry.
>
> All the best,
>
> Martin Herzfeld, Interstate Renewable Energy Council (IREC) Certified
> Master Trainer ™ for Photovoltaics (PV) Installation Professional #IREC
> 10037
> Contract Training Provider (CTP)
> Adjunct Professor, Energy
>
> California Solar & Electrical Contractor License  #00833782  C46, C10,
> D56, D31, C-7 - Since 2004
> Solar, Electrical, Trenching, Pole Installation & Maintenance,
> Instrumentation
>
> Contract Solar (PV) Technical Inspector - 3rd Party Inspections
> Underwriters Laboratories (UL) Certified PV Installer #17, OSHA 30
> OSHA-Authorized Construction Trainer #32-0105338
> CompTIA Certified Technical Classroom Trainer (CTT+) #T3NSZCNBBKB4QTQG
>
> * Professional Member, International Association of Electrical Inspectors
> #7035507 - Since 2006
> * Accredited and Registered North 

Re: [RE-wrenches] Rapid Shutdown Compliance

[Christopher Warfel]

I believe Rapid Shutdown was mostly a solution looking for a problem.   
The only way I see this becoming "reasonable" is to present "grievances" 
to the Code Making Panel WITH a solution for their consideration.  Based 
on experience from being part of an outreach program that taught 
approximately 10k firefighters over four years, I have asked that they 
add to the Directory, the language that states what type of solar 
electric system is on site (Microinverter, dc optimizer, string, 
multimode, grid isolated) so that First Responders don't have to guess.  
I realize this is different than MLPE, but it targets the person who 
Rapid Shutdown came into being for, and that was the First Responder.   
Chris



On 5/6/2020 10:37 PM, Ray wrote:


Spending more time on the roof, while putting more equipment and parts 
to meet MLPE, means more trips up the ladder, which increases, not 
decreases the #1 worker safety danger: Falls. Please correct me if I 
have somehow misunderstood this, but MLPE is not making installers 
safer based on OSHA information provided.   Also after installation, 
which system is more likely to require workers to return to work on 
the roof, pulling up modules, trying to find problem equipment?  More 
connections is More safe?  Really?  I haven't had to climb back up on 
the roof on any of my older, lower voltage off grid work in almost a 
decade.


Once again, MLPE has its place, (larger systems, multiple subarrays, 
higher voltage) but we should have sensible exemptions as have been 
mentioned already.  We are endangering ourselves and our employees 
needlessly, to comply with 690.12.


Ray Walters
Remote Solar
303 505-8760
On 5/6/20 8:41 PM, drake.chamber...@redwoodalliance.org wrote:


Interestingly enough, the data on the link 
 provided 
shows accidents from gas explosions, falls, health problems and  
industrial injuries. None of these incidents could have been 
prevented by module level power electronics. This is typical of the 
data that I've seen so far.


---


On 2020-05-06 17:22, Martin Herzfeld wrote:


There could be an issue of encouraging MLPE for worker safety?
1.  This is data involving incidents with workers in the OSHA 
Fatalities and Catastrophe Investigation Summaries found here:

https://www.osha.gov/pls/imis/AccidentSearch.search?p_logger=1_description=_Abstract=solar_keywordAll=All=05=05=2002=05=05=2021=
2.  In the past I've observed an arc fault at the module level with 
traditional string systems without a listed arc-fault circuit 
interrupter NEC/CEC 690.11. The function in NEC/CEC 690.12 would be 
- to _reduce the shock hazard _- for /emergency responders/ or 
/firefighters? (NEC 2020)./ However, I've observed thermal events in 
the panelboard with plans and workmanship issues.
On the other hand, falls are the #1 reason for incidents in the 
construction industry.

All the best,

Martin Herzfeld, Interstate Renewable Energy Council (IREC) 
Certified Master Trainer ™ for Photovoltaics (PV) Installation 
Professional #IREC 10037

Contract Training Provider (CTP)
Adjunct Professor, Energy

California Solar & Electrical Contractor License  #00833782  C46, 
C10, D56, D31, C-7 - Since 2004
Solar, Electrical, Trenching, Pole Installation & Maintenance, 
Instrumentation


Contract Solar (PV) Technical Inspector - 3rd Party Inspections
Underwriters Laboratories (UL) Certified PV Installer #17, OSHA 30
OSHA-Authorized Construction Trainer #32-0105338
CompTIA Certified Technical Classroom Trainer (CTT+) #T3NSZCNBBKB4QTQG

* Professional Member, International Association of Electrical 
Inspectors  #7035507 - Since 2006
* Accredited and Registered North American Board of Certified Energy 
Practitioners (NABCEP) Continuing Education (CE) Training Provider


On Thu, Apr 30, 2020, 8:29 AM > wrote:



I would like to see real data on the fire risk of string
inverters. Anecdotal problems are not data.
The industry is definitely heading toward MLPE due to the rapid
shutdown requirements. In many cases MLPE makes sense, in other
cases it doesn't.
Systems that are more cost effective and reliable can often be
built by using string inverters.
---


On 2020-04-29 22:05, Jason Szumlanski wrote:

"Rapid Shutdown does not prevent fires."

Not true. If the effect of RS is to steer the market to
MLPE, I believe it has a significant impact on reducing fire
risk. As one who has watched a DC conductor fire smolder out
of control, I am sold on an AC module or microinverter
architecture. While RS on a DC array doesn't necessarily
reduce fire risk within the array, it still has the
potential to reduce severity and spread. Nothing is going to
prevent all fires. I get that. We're talking about risk

Re: [RE-wrenches] Rapid Shutdown Compliance

[Ray]

Spending more time on the roof, while putting more equipment and parts 
to meet MLPE, means more trips up the ladder, which increases, not 
decreases the #1 worker safety danger: Falls. Please correct me if I 
have somehow misunderstood this, but MLPE is not making installers safer 
based on OSHA information provided.   Also after installation, which 
system is more likely to require workers to return to work on the roof, 
pulling up modules, trying to find problem equipment?  More connections 
is More safe?  Really?  I haven't had to climb back up on the roof on 
any of my older, lower voltage off grid work in almost a decade.


Once again, MLPE has its place, (larger systems, multiple subarrays, 
higher voltage) but we should have sensible exemptions as have been 
mentioned already.  We are endangering ourselves and our employees 
needlessly, to comply with 690.12.


Ray Walters
Remote Solar
303 505-8760

On 5/6/20 8:41 PM, drake.chamber...@redwoodalliance.org wrote:


Interestingly enough, the data on the link 
 provided 
shows accidents from gas explosions, falls, health problems and  
industrial injuries. None of these incidents could have been prevented 
by module level power electronics. This is typical of the data that 
I've seen so far.


---


On 2020-05-06 17:22, Martin Herzfeld wrote:


There could be an issue of encouraging MLPE for worker safety?
1.  This is data involving incidents with workers in the OSHA 
Fatalities and Catastrophe Investigation Summaries found here:

https://www.osha.gov/pls/imis/AccidentSearch.search?p_logger=1_description=_Abstract=solar_keywordAll=All=05=05=2002=05=05=2021=
2.  In the past I've observed an arc fault at the module level with 
traditional string systems without a listed arc-fault circuit 
interrupter NEC/CEC 690.11. The function in NEC/CEC 690.12 would be - 
to _reduce the shock hazard _- for /emergency responders/ or 
/firefighters? (NEC 2020)./  However, I've observed thermal events in 
the panelboard with plans and workmanship issues.
On the other hand, falls are the #1 reason for incidents in the 
construction industry.

All the best,

Martin Herzfeld, Interstate Renewable Energy Council (IREC) Certified 
Master Trainer ™ for Photovoltaics (PV) Installation Professional 
#IREC 10037

Contract Training Provider (CTP)
Adjunct Professor, Energy

California Solar & Electrical Contractor License #00833782  C46, C10, 
D56, D31, C-7 - Since 2004
Solar, Electrical, Trenching, Pole Installation & Maintenance, 
Instrumentation


Contract Solar (PV) Technical Inspector - 3rd Party Inspections
Underwriters Laboratories (UL) Certified PV Installer #17, OSHA 30
OSHA-Authorized Construction Trainer #32-0105338
CompTIA Certified Technical Classroom Trainer (CTT+) #T3NSZCNBBKB4QTQG

* Professional Member, International Association of Electrical 
Inspectors  #7035507 - Since 2006
* Accredited and Registered North American Board of Certified Energy 
Practitioners (NABCEP) Continuing Education (CE) Training Provider


On Thu, Apr 30, 2020, 8:29 AM > wrote:



I would like to see real data on the fire risk of string
inverters. Anecdotal problems are not data.
The industry is definitely heading toward MLPE due to the rapid
shutdown requirements. In many cases MLPE makes sense, in other
cases it doesn't.
Systems that are more cost effective and reliable can often be
built by using string inverters.
---


On 2020-04-29 22:05, Jason Szumlanski wrote:

"Rapid Shutdown does not prevent fires."

Not true. If the effect of RS is to steer the market to MLPE,
I believe it has a significant impact on reducing fire risk.
As one who has watched a DC conductor fire smolder out of
control, I am sold on an AC module or microinverter
architecture. While RS on a DC array doesn't necessarily
reduce fire risk within the array, it still has the potential
to reduce severity and spread. Nothing is going to prevent
all fires. I get that. We're talking about risk mitigation
when it comes to RS.
As for "dependable string inverters," the one dependable
feature is failure at least once in the module lifetime,
accompanied by a shocking repair bill.
I'm not a shiny object following kind of guy, but the writing
is on the wall. MLPE is the future. Modular, serviceable,
disposable if you will. Like it or not, Edison is going to
lose this battle to Tesla (Tom vs Nikola). And I live less
than 5 minutes away from Tommy E's winter home in Fort Myers,
FL. And I "grew up" in the industry living off-grid in DC
power. But AC distribution wins for safety at various scales.



On Wed, Apr 29, 2020, 9:42 PM

Re: [RE-wrenches] Rapid Shutdown Compliance

[drake . chamberlin]

Interestingly enough, the data on the link [9] provided shows accidents
from gas explosions, falls, health problems and  industrial injuries.
None of these incidents could have been prevented by module level power
electronics. This is typical of the data that I've seen so far. 


---

On 2020-05-06 17:22, Martin Herzfeld wrote:

There could be an issue of encouraging MLPE for worker safety? 

1.  This is data involving incidents with workers in the OSHA Fatalities and Catastrophe Investigation Summaries found here: 
https://www.osha.gov/pls/imis/AccidentSearch.search?p_logger=1_description=_Abstract=solar_keywordAll=All=05=05=2002=05=05=2021= 

2.  In the past I've observed an arc fault at the module level with traditional string systems without a listed arc-fault circuit interrupter NEC/CEC 690.11. The function in NEC/CEC 690.12 would be - to reduce the shock hazard - for _emergency responders_ or _firefighters? (NEC 2020)._  However, I've observed thermal events in the panelboard with plans and workmanship issues.  

On the other hand, falls are the #1 reason for incidents in the construction industry.  

All the best, 


Martin Herzfeld, Interstate Renewable Energy Council (IREC) Certified Master 
Trainer (tm) for Photovoltaics (PV) Installation Professional #IREC 10037
Contract Training Provider (CTP)
Adjunct Professor, Energy

California Solar & Electrical Contractor License  #00833782  C46, C10, D56, 
D31, C-7 - Since 2004
Solar, Electrical, Trenching, Pole Installation & Maintenance, Instrumentation

Contract Solar (PV) Technical Inspector - 3rd Party Inspections 
Underwriters Laboratories (UL) Certified PV Installer #17, OSHA 30

OSHA-Authorized Construction Trainer #32-0105338
CompTIA Certified Technical Classroom Trainer (CTT+) #T3NSZCNBBKB4QTQG

* Professional Member, International Association of Electrical Inspectors  
#7035507 - Since 2006
* Accredited and Registered North American Board of Certified Energy 
Practitioners (NABCEP) Continuing Education (CE) Training Provider

On Thu, Apr 30, 2020, 8:29 AM  wrote: 

I would like to see real data on the fire risk of string inverters. Anecdotal problems are not data. 

The industry is definitely heading toward MLPE due to the rapid shutdown requirements. In many cases MLPE makes sense, in other cases it doesn't.  

Systems that are more cost effective and reliable can often be built by using string inverters. 
--- 

On 2020-04-29 22:05, Jason Szumlanski wrote: 


"Rapid Shutdown does not prevent fires."

Not true. If the effect of RS is to steer the market to MLPE, I believe it has a significant impact on reducing fire risk. As one who has watched a DC conductor fire smolder out of control, I am sold on an AC module or microinverter architecture. While RS on a DC array doesn't necessarily reduce fire risk within the array, it still has the potential to reduce severity and spread. Nothing is going to prevent all fires. I get that. We're talking about risk mitigation when it comes to RS.  

As for "dependable string inverters," the one dependable feature is failure at least once in the module lifetime, accompanied by a shocking repair bill. 

I'm not a shiny object following kind of guy, but the writing is on the wall. MLPE is the future. Modular, serviceable, disposable if you will. Like it or not, Edison is going to lose this battle to Tesla (Tom vs Nikola). And I live less than 5 minutes away from Tommy E's winter home in Fort Myers, FL. And I "grew up" in the industry living off-grid in DC power. But AC distribution wins for safety at various scales. 

On Wed, Apr 29, 2020, 9:42 PM  wrote: 

Rapid Shutdown does not prevent fires; it was originally drafted to allow firefighters to vent a roof without being hindered by energized PV arrays. This rule was expanded to include other DC wiring from PV sources. 

As for PV safety, I'd like to see some significant, statistical evidence that shows there is a major fire danger from PV relative to other sources. A fire from a solar array gets a lot more press than one from a gas leak, bad wiring or an ash tray emptied into a wastepaper basket. 

Large public buildings should have all the protection that is available. Does one size fit all? 

Would it be reasonable to allow residential installations under 12 kW, with 1/4 of the roof adjacent to the array available for venting, to be excepted from 690.12? What about sparsely occupied commercial buildings with ample roof area open for ventilation?   

Many of us have chosen to work with renewable energy technology to lessen the harms caused by fossil fuel extraction and combustion. The need for non-carbon based energy sources has become extremely clear. 

The old string inverters still chug along year after year, with little or no maintenance. Someone must pay for the ongoing maintenance of module level electronics. Dependable string inverter systems should be allowed unless statically significant danger can be demonstrated. 


Drake

---

On 2020-04-29 

Re: [RE-wrenches] Rapid Shutdown Compliance

[Martin Herzfeld]

There could be an issue of encouraging MLPE for worker safety?

1.  This is data involving incidents with workers in the OSHA Fatalities
and Catastrophe Investigation Summaries found here:
https://www.osha.gov/pls/imis/AccidentSearch.search?p_logger=1_description=_Abstract=solar_keywordAll=All=05=05=2002=05=05=2021=

2.  In the past I've observed an arc fault at the module level with
traditional string systems without a listed arc-fault circuit interrupter
NEC/CEC 690.11. The function in NEC/CEC 690.12 would be - to *reduce the
shock hazard *- for *emergency responders* or *firefighters? (NEC 2020).*
However, I've observed thermal events in the panelboard with plans and
workmanship issues.

On the other hand, falls are the #1 reason for incidents in the
construction industry.

All the best,

Martin Herzfeld, Interstate Renewable Energy Council (IREC) Certified
Master Trainer ™ for Photovoltaics (PV) Installation Professional #IREC
10037
Contract Training Provider (CTP)
Adjunct Professor, Energy

California Solar & Electrical Contractor License  #00833782  C46, C10, D56,
D31, C-7 - Since 2004
Solar, Electrical, Trenching, Pole Installation & Maintenance,
Instrumentation

Contract Solar (PV) Technical Inspector - 3rd Party Inspections
Underwriters Laboratories (UL) Certified PV Installer #17, OSHA 30
OSHA-Authorized Construction Trainer #32-0105338
CompTIA Certified Technical Classroom Trainer (CTT+) #T3NSZCNBBKB4QTQG

* Professional Member, International Association of Electrical Inspectors
#7035507 - Since 2006
* Accredited and Registered North American Board of Certified Energy
Practitioners (NABCEP) Continuing Education (CE) Training Provider


On Thu, Apr 30, 2020, 8:29 AM  wrote:

>
> I would like to see real data on the fire risk of string inverters.
> Anecdotal problems are not data.
>
> The industry is definitely heading toward MLPE due to the rapid shutdown
> requirements. In many cases MLPE makes sense, in other cases it doesn't.
>
> Systems that are more cost effective and reliable can often be built by
> using string inverters.
> ---
>
>
>
>
> On 2020-04-29 22:05, Jason Szumlanski wrote:
>
> "Rapid Shutdown does not prevent fires."
>
> Not true. If the effect of RS is to steer the market to MLPE, I believe it
> has a significant impact on reducing fire risk. As one who has watched a DC
> conductor fire smolder out of control, I am sold on an AC module or
> microinverter architecture. While RS on a DC array doesn't necessarily
> reduce fire risk within the array, it still has the potential to reduce
> severity and spread. Nothing is going to prevent all fires. I get that.
> We're talking about risk mitigation when it comes to RS.
>
> As for "dependable string inverters," the one dependable feature is
> failure at least once in the module lifetime, accompanied by a shocking
> repair bill.
>
> I'm not a shiny object following kind of guy, but the writing is on the
> wall. MLPE is the future. Modular, serviceable, disposable if you will.
> Like it or not, Edison is going to lose this battle to Tesla (Tom vs
> Nikola). And I live less than 5 minutes away from Tommy E's winter home in
> Fort Myers, FL. And I "grew up" in the industry living off-grid in DC
> power. But AC distribution wins for safety at various scales.
>
>
>
>
>
>
> On Wed, Apr 29, 2020, 9:42 PM 
> wrote:
>
> Rapid Shutdown does not prevent fires; it was originally drafted to allow
> firefighters to vent a roof without being hindered by energized PV arrays.
> This rule was expanded to include other DC wiring from PV sources.
>
> As for PV safety, I'd like to see some significant, statistical evidence
> that shows there is a major fire danger from PV relative to other sources.
> A fire from a solar array gets a lot more press than one from a gas leak,
> bad wiring or an ash tray emptied into a wastepaper basket.
>
> Large public buildings should have all the protection that is available.
> Does one size fit all?
>
> Would it be reasonable to allow residential installations under 12 kW,
> with 1/4 of the roof adjacent to the array available for venting, to be
> excepted from 690.12? What about sparsely occupied commercial buildings
> with ample roof area open for ventilation?
>
> Many of us have chosen to work with renewable energy technology to lessen
> the harms caused by fossil fuel extraction and combustion. The need for
> non-carbon based energy sources has become extremely clear.
>
> The old string inverters still chug along year after year, with little or
> no maintenance. Someone must pay for the ongoing maintenance of module
> level electronics. Dependable string inverter systems should be allowed
> unless statically significant danger can be demonstrated.
>
> Drake
> ---
>
>
>
> On 2020-04-29 16:01, Jason Szumlanski wrote:
>
> I have been to several PV fires for string inverter systems, both
> commercial and residential, and have seen many DC systems at serious risk
> of fires or in various stages of melted insulation and 

Re: [RE-wrenches] Rapid Shutdown Compliance Secure Power

[don]

Thanks for the suggestion of using a SPDT; but there is a who's-on-first problem there. Normally the switch supplies utility power to the RS controller. When that goes down, we want AC from the Secure Power. But that won't activate until the inverter gets solar power, which is now cut off by the RS system that needs AC to activate it firstDon BarchEnergy Solar
Date: Tue, 5 May 2020 08:35:51 -0400
From: Tump <t...@swnl.net>
To: RE-wrenches <re-wrenches@lists.re-wrenches.org>
Subject: Re: [RE-wrenches] Rapid Shutdown Compliance
Message-ID: <7273560e-f55b-4007-824e-fd6bb740a...@swnl.net>
Content-Type: text/plain; charset="utf-8"

How about a SPDT switch, all one is doing is supplying AC voltage from the utility,  (powering the MLPE box's Ac to Dc converter) their utility or SSP from the SB's utility. 
> On May 4, 2020, at 8:04 PM, <d...@energysolarnow.com> <d...@energysolarnow.com> wrote:
> 
> Many customers ask about keeping power alive when the grid is down. Besides battery backup, I advocate the Secure Power feature of SunnyBoy inverters.
> But the problem with MLPE is that it is incompatible with Secure Power. When the grid goes down the MLPE disconnect each solar module's DC feed. So when the Secure Power activation switch is thrown there is no DC to power it up, even if the Secure Power output is fed to the MLPE power feedin.
> So I have only been able to install SunnyBoy Secure Power on existing systems without Rapid Shutdown MLPE. 
> 
> Does anyone have a work around for this, short of installing a separate small battery backed inverter to keep the MLPE alive?
> 
> Don Barch
> Energy Solar
> ___
> List sponsored by Redwood Alliance



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Re: [RE-wrenches] Rapid Shutdown Compliance

[Eric Smiley]

We are running into the same problem with battery back-up, grid-tie
systems. Many Rapid Shutdown solutions turn off the array when utility
power is off, which isn't desirable. We have one client with an underground
service and the local AHJ wants the RS initiating device near the meter (as
our Canadian EC requires) which is hundreds of feet away. In this
circumstance but without back-up, we would usually just use an AC
disconnect near the meter to initiate RS, but now we're facing the prospect
of running a new control circuit all the way back to the pole or requesting
a variance.

Eric Smiley, P.Eng.

Project Manager, North Island

E:  e...@vecoop.ca

T:  1-888-386-0116 ext 702 (toll free)

C:  250-703-6004

W:  viridianenergy.ca 



RENEWABLE POWER NOW


On Mon, 4 May 2020 at 17:04,  wrote:

> Many customers ask about keeping power alive when the grid is down.
> Besides battery backup, I advocate the Secure Power feature of SunnyBoy
> inverters.
> But the problem with MLPE is that it is incompatible with Secure Power.
> When the grid goes down the MLPE disconnect each solar module's DC feed. So
> when the Secure Power activation switch is thrown there is no DC to power
> it up, even if the Secure Power output is fed to the MLPE power feedin.
> So I have only been able to install SunnyBoy Secure Power on existing
> systems without Rapid Shutdown MLPE.
>
> Does anyone have a work around for this, short of installing a separate
> small battery backed inverter to keep the MLPE alive?
>
> Don Barch
> Energy Solar
> ___
> List sponsored by Redwood Alliance
>
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Re: [RE-wrenches] Rapid Shutdown Compliance

[Tump]

How about a SPDT switch, all one is doing is supplying AC voltage from the 
utility,  (powering the MLPE box's Ac to Dc converter) their utility or SSP 
from the SB’s utility. 
> On May 4, 2020, at 8:04 PM,  
>  wrote:
> 
> Many customers ask about keeping power alive when the grid is down. Besides 
> battery backup, I advocate the Secure Power feature of SunnyBoy inverters.
> But the problem with MLPE is that it is incompatible with Secure Power. When 
> the grid goes down the MLPE disconnect each solar module's DC feed. So when 
> the Secure Power activation switch is thrown there is no DC to power it up, 
> even if the Secure Power output is fed to the MLPE power feedin.
> So I have only been able to install SunnyBoy Secure Power on existing systems 
> without Rapid Shutdown MLPE. 
> 
> Does anyone have a work around for this, short of installing a separate small 
> battery backed inverter to keep the MLPE alive?
> 
> Don Barch
> Energy Solar
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Re: [RE-wrenches] Rapid Shutdown Compliance

[don]

Many customers ask about keeping power alive when the grid is down. Besides battery backup, I advocate the Secure Power feature of SunnyBoy inverters. But the problem with MLPE is that it is incompatible with Secure Power. When the grid goes down the MLPE disconnect each solar module's DC feed. So when the Secure Power activation switch is thrown there is no DC to power it up, even if the Secure Power output is fed to the MLPE power feedin. So I have only been able to install SunnyBoy Secure Power on existing systems without Rapid Shutdown MLPE. Does anyone have a work around for this, short of installing a separate small battery backed inverter to keep the MLPE alive? Don BarchEnergy Solar
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Re: [RE-wrenches] Rapid Shutdown Compliance

[Martin Herzfeld]

1. I use a MLPE residential ground-mounted solution - rapid shutdown or
not.  w/Accessible MLPE.

2. There is a maximum physical string length for me to keep in mind, for
instance, found here:

"In the context of this document, string length refers to the number of
optimizers and modules in the string. When designing the installation make
sure to maintain the maximum physical string length as well: The total
cable length of the string (excluding power optimizers’ conductors) should
not exceed 1000ft./300m from DC+ to DC- of the inverter (2,300ft./700m when
using the SE14.4KUS, SE30KUS,SE33.3KUS, SE43.2KUS, SE66.6KUS and SE100KUS
inverters)"
https://www.solaredge.com/sites/default/files/string_sizing_na.pdf


All the best,

Martin Herzfeld, Interstate Renewable Energy Council (IREC) Certified
Master Trainer ™ for Photovoltaics (PV) Installation Professional #IREC
10037
Contract Training Provider (CTP)
Adjunct Professor, Energy

California Solar & Electrical Contractor License  #00833782  C46, C10, D56,
D31, C-7
Solar, Electrical, Trenching, Pole Installation & Maintenance,
Instrumentation

Contract Solar (PV) Technical Inspector - 3rd Party Inspections
Underwriters Laboratories (UL) Certified PV Installer #17, OSHA 30
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* Professional Member, International Association of Electrical Inspectors
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Practitioners (NABCEP) Continuing Education (CE) Training Provider

On Wed, Apr 29, 2020, 8:17 AM Jay  wrote:

> Hi Drake
>
> I will disagree, there have been many roof top fires.
>
> But regardless we have to do these new regulations and I for one welcome
> the safety.
>
> The main issue is accessing the faulty/suspect component under the module
> possibly requiring removing multiple modules, a slow and expensive process.
>
> My technique is to install the MLPE at the edges of the array, using wire
> extensions. That way at most I have to remove a single module.  And Im
> working on a drop bracket which would allow better cooling and easier
> access without module removal to the MLPE, greatly reducing time to swap.
>
> Jay
>
> Peltz Power.
>
>
>
>
>
> On Apr 29, 2020, at 7:59 AM, drake.chamber...@redwoodalliance.org wrote:
>
> 
>
> Clearly, rapid shutdown increases cost and reduces reliability. Given the
> excellent safety record of PV, prior to rapid shutdown being required, it
> is unnecessary. The few anecdotal incidents of PV fires were not enough to
> justify the requirement, especially on smaller systems.
>
> According to a friend who worked for a local installation company that
> went under, a big part of the reason for their failure was the chronic
> replacement of microinverters and optimizers.
>
> What steps can be taken to create some balance in the rapid shutdown
> requirements that are in the NEC?
>
>
> ---
>
>
>
> On 2020-04-29 07:27, Sky Sims wrote:
>
> So far rapid shutdown has been a nightmare. It's added a lot of cost for
> no measurable benefit.
> Using always off devices like midnight solar and Tigo makes it impossible
> to test open circuit voltages. Which opens the door to tons of problems
> when commissioning systems.
> Also we've been trying out midnight Solar's product and have had an absurd
> failure rate. Which means lots of truck rolls and troubleshooting and
> system downtime. They send replacement product but they aren't paying for
> the lost weeks of productivity.
> We have Tigo product in hand and are deciding which project to try it on.
> But our big concern about using it is not only the inability to confirm
> open circuit voltage of the strings but also the way panels bypass if the
> device doesn't allow the panel to connect properly. Both of these features
> are a recipe for problems and potential troubleshooting nightmares. The
> warranty from Tigo doesn't cover our expense if the product fails. And
> that's really what our reservations about the product boil down to right
> now. If we're on a job with 50 units and one fails, the contractor or the
> homeowner will be the ones eating the expense of finding it and replacing
> it. There has to be a better option.
>
> Sky Sims
> Https://EcologicalSystems.biz
>
> On Apr 28, 2020, at 7:46 PM, Corey Shalanski  wrote:
>
> Now that 690.12 of the *NEC* 2017 has been in effect for several years, I
> am curious how designers and installers are meeting the associated
> requirements with string inverter-based systems (*not* considering
> microinverters or DC optimizers). I am generally a fan of the KISS
> principle, and as best I can determine the *Tigo* TS4-F device is one of
> the simplest options currently available on the market. What are others
> finding?
>
> I'd love to hear about favored options for complying with rapid shutdown.
> Any success stories? or better yet, any early failures?
>
> --
> Corey Shalanski
> Jah Light 

Re: [RE-wrenches] Rapid Shutdown Compliance

[Dave Tedeyan]

I was told at a training a couple years ago that there were going to be
some modules coming out soon that had a microchip in the module junction
box which would replace the diodes and effectively work as MLPE. I have not
heard anything about that recently though. Does anyone know what I am
talking about? It seems that this would solve many of the issues associated
with MLPE, but still be able to have the benefits.
Cheers,
Dave

*Dave Tedeyan, PE*
Senior Engineer | Taitem Engineering, PC

110 South Albany Street | Ithaca, NY 14850
o. *607.277.1118 x121*  f. 607.277.2119
www.taitem.com

Solar • Sustainability • Energy • Design
Certified B-Corporation since 2013


On Thu, Apr 30, 2020 at 11:54 AM Dan Fink  wrote:

> Since I only work with off-grid systems, I find the 690.12 exception
> starting in NEC 2017 for ground-mounted systems with DC equipment in a
> separate structure intended only for PV components, is very useful for
> avoiding expensive, unneeded RSS equipment. Many folks don't like the idea
> of a battery bank and buzzing equipment and fans in their dwelling anyway,
> so the "power shed" idea works well, and around here structures 120 square
> feet and under don't need building permits. I did see one system pass with
> 3 PV modules on the roof of the power shed, though technically that's not
> part of the 690.12 exception.
>
> Dan Fink
> Owner, Buckville Energy Consulting
> NABCEP Certified PV System Inspector
> IREC Certified Instructor™ for:
> ~ PV Installation Professional
> ~ Small Wind Installer
> NABCEP Registered Continuing Education Providers
> d anbo...@gmail.com
> 970-672-4342
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Re: [RE-wrenches] Rapid Shutdown Compliance

[Dan Fink]

Since I only work with off-grid systems, I find the 690.12 exception
starting in NEC 2017 for ground-mounted systems with DC equipment in a
separate structure intended only for PV components, is very useful for
avoiding expensive, unneeded RSS equipment. Many folks don't like the idea
of a battery bank and buzzing equipment and fans in their dwelling anyway,
so the "power shed" idea works well, and around here structures 120 square
feet and under don't need building permits. I did see one system pass with
3 PV modules on the roof of the power shed, though technically that's not
part of the 690.12 exception.

Dan Fink
Owner, Buckville Energy Consulting
NABCEP Certified PV System Inspector
IREC Certified Instructor™ for:
~ PV Installation Professional
~ Small Wind Installer
NABCEP Registered Continuing Education Providers
d anbo...@gmail.com
970-672-4342
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Re: [RE-wrenches] Rapid Shutdown Compliance

[drake . chamberlin]

I would like to see real data on the fire risk of string inverters.
Anecdotal problems are not data. 


The industry is definitely heading toward MLPE due to the rapid shutdown
requirements. In many cases MLPE makes sense, in other cases it doesn't.


Systems that are more cost effective and reliable can often be built by
using string inverters. 
--- 


On 2020-04-29 22:05, Jason Szumlanski wrote:


"Rapid Shutdown does not prevent fires."

Not true. If the effect of RS is to steer the market to MLPE, I believe it has a significant impact on reducing fire risk. As one who has watched a DC conductor fire smolder out of control, I am sold on an AC module or microinverter architecture. While RS on a DC array doesn't necessarily reduce fire risk within the array, it still has the potential to reduce severity and spread. Nothing is going to prevent all fires. I get that. We're talking about risk mitigation when it comes to RS.  

As for "dependable string inverters," the one dependable feature is failure at least once in the module lifetime, accompanied by a shocking repair bill. 

I'm not a shiny object following kind of guy, but the writing is on the wall. MLPE is the future. Modular, serviceable, disposable if you will. Like it or not, Edison is going to lose this battle to Tesla (Tom vs Nikola). And I live less than 5 minutes away from Tommy E's winter home in Fort Myers, FL. And I "grew up" in the industry living off-grid in DC power. But AC distribution wins for safety at various scales. 

On Wed, Apr 29, 2020, 9:42 PM  wrote: 

Rapid Shutdown does not prevent fires; it was originally drafted to allow firefighters to vent a roof without being hindered by energized PV arrays. This rule was expanded to include other DC wiring from PV sources. 

As for PV safety, I'd like to see some significant, statistical evidence that shows there is a major fire danger from PV relative to other sources. A fire from a solar array gets a lot more press than one from a gas leak, bad wiring or an ash tray emptied into a wastepaper basket. 

Large public buildings should have all the protection that is available. Does one size fit all? 

Would it be reasonable to allow residential installations under 12 kW, with 1/4 of the roof adjacent to the array available for venting, to be excepted from 690.12? What about sparsely occupied commercial buildings with ample roof area open for ventilation?   

Many of us have chosen to work with renewable energy technology to lessen the harms caused by fossil fuel extraction and combustion. The need for non-carbon based energy sources has become extremely clear. 

The old string inverters still chug along year after year, with little or no maintenance. Someone must pay for the ongoing maintenance of module level electronics. Dependable string inverter systems should be allowed unless statically significant danger can be demonstrated. 


Drake

---

On 2020-04-29 16:01, Jason Szumlanski wrote: 

I have been to several PV fires for string inverter systems, both commercial and residential, and have seen many DC systems at serious risk of fires or in various stages of melted insulation and connectors. Most of these systems have exhibited good to excellent workmanship. Things just went wrong. Some were traceable to animal damage, wind, or other unmitigated factors, and some were unexplained. I disagree that there isn't justification for rapid shutdown.  

In my opinion, what we need is some additional innovation and competition in the MLPE space. Reliability is clearly a key factor, but there is no denying that MLPE has added safety benefits among other benefits. And if you do enough volume and set up your business for efficiency (standardization of product offerings), MLPE isn't much more expensive. It becomes a negligible cost relative to the benefit. The value proposition is easy to convey. There are limits to this, but for the majority of residential and small commercial installations, MLPE has become the de facto standard around here. String inverters are dinos, and replacing 8-12 year old transformer based inverters is many times more annoying than some MLPE swaps. I will admit that the roofs around here are pretty easy to walk, so that is a factor that might not apply to you. 

If you go under due to manufacturer product failures, you are not writing your contracts right or not charging enough for service issues beyond your control. I believe that's a red herring. You might suffer some reputation damage, but for someone that has been installing MLPE for over a decade, that is totally manageable. Consumers find a service call to replace MLPE a LOT more palatable than a surprise inverter replacement that could cost thousands of dollars. People just don't plan for that. 

Regarding rapid shutdown devices, I have also come across a few that "someone" has bypassed around here. I don't know if they were never installed properly or disabled/bypassed due to failure. It seemed suspicious to me at 

Re: [RE-wrenches] Rapid Shutdown Compliance

[Tump]

I agree w/ Ray as most of my work is Off grid. Incorporating addition failure 
points ( RSD modules. optimizers ect.) for a system that is usually quite a 
distance from service, be it my service or the fire departments, I find the 
justification very hard. Ive replaced your micro inverters at 0* due to 
failure.  
Still am not to comfortable w/ them.
> On Apr 30, 2020, at 11:10 AM, August Goers  wrote:
> 
> All - Ray has a good point, the discussion here is really about two different 
> types of systems - mainstream ongrid PV, and small scale (and a relatively 
> small market) offgrid PV. It's really tough to design a small offgrid system 
> (especially DC coupled) with rapid shutdown. I think it's just a case that 
> the market is so small that the manufactures aren't focusing their products 
> on it. Our business doesn't do much offgrid, so I'm not familiar with the 
> products but understand the difficulty. For ongrid PV with or without energy 
> storage, I still argue that MPLE or microinverters are 100% the now and 
> future, and fighting against that is a losing battle.
> 
> I think we should see more and more offgrid ability coming from the big 
> players SolarEdge, Tesla, (maybe Enphase) etc which will all be easy to pair 
> with rapid shutdown enabled PV.
> 
> August
>  
> 
> 
> On Thu, Apr 30, 2020 at 7:12 AM Ray  > wrote:
> Hi Jerry;
> 
> This isn't about us not being willing to learn the tech.  All of us are 
> constantly learning about new code changes, new inverters, and solar modules 
> that change specs every few months.  We are voluntarily adopting new 
> technology (like Lithium Ion batteries) when that technology is cost 
> effective and reliable.  
> To continue your smart phone analogy, the current situation is like forcing 
> people in the country to give up their hard lines, when their is only spotty 
> 3G service available in their area.  Its not that we are Luddites; the 
> equipment is still not quite ready for prime time.   Having some basic 
> exemptions for small, lower voltage systems off grid is not unreasonable.
> Ray Walters
> Remote Solar
> 303 505-8760
> On 4/30/20 2:33 AM, Jerry Shafer wrote:
>> Wrenches
>> We are taking two very different issues and mixing them together. RSD and 
>> Arc-fault are different, arc fault will and does prevent fires, RSD was 
>> brought out of the need to vent a roof that even with the meter pulled have 
>> 500 volts and resulted shocks to fire fighters by cutting into roofs or 
>> nearby conduite. This is fact not conjecture.
>> Arc fault is a fire preventer but requires nothing on the roof when using 
>> string level inverters. Now both RSD and arc-fault in off grid increase the 
>> complexity but the new charge controllers fit the arc and Tigo fixes the RSD 
>> issues. 
>> I know everyone of you learned to use a smart phone and can now adapt again 
>> to this new tech, we have to be leaders in this industry and not well you 
>> know.
>> Jerry
>> NABCEP PV Inspector.
>> Been in this industry since 1978 
>> 
>> On Wed, Apr 29, 2020, 6:57 PM Jay > > wrote:
>> Hi Drake 
>> 
>> I will disagree, there have been many roof top fires. 
>> 
>> But regardless we have to do these new regulations and I for one welcome the 
>> safety. 
>> 
>> The main issue is accessing the faulty/suspect component under the module 
>> possibly requiring removing multiple modules, a slow and expensive process. 
>> 
>> My technique is to install the MLPE at the edges of the array, using wire 
>> extensions. That way at most I have to remove a single module.  And Im 
>> working on a drop bracket which would allow better cooling and easier access 
>> without module removal to the MLPE, greatly reducing time to swap. 
>> 
>> Jay
>> 
>> Peltz Power. 
>> 
>> 
>> 
>> 
>> 
>>> On Apr 29, 2020, at 7:59 AM, drake.chamber...@redwoodalliance.org 
>>>  wrote:
>>> 
>>> 
>>> Clearly, rapid shutdown increases cost and reduces reliability. Given the 
>>> excellent safety record of PV, prior to rapid shutdown being required, it 
>>> is unnecessary. The few anecdotal incidents of PV fires were not enough to 
>>> justify the requirement, especially on smaller systems.
>>> 
>>> According to a friend who worked for a local installation company that went 
>>> under, a big part of the reason for their failure was the chronic 
>>> replacement of microinverters and optimizers.
>>> 
>>> What steps can be taken to create some balance in the rapid shutdown 
>>> requirements that are in the NEC?
>>> 
>>> 
>>> ---
>>>  
>>> 
>>> On 2020-04-29 07:27, Sky Sims wrote:
>>> 
 So far rapid shutdown has been a nightmare. It's added a lot of cost for 
 no measurable benefit.
 Using always off devices like midnight solar and Tigo makes it impossible 
 to test open circuit voltages. Which opens the door to tons
  of problems when commissioning systems. 
 Also 

Re: [RE-wrenches] Rapid Shutdown Compliance

[August Goers]

All - Ray has a good point, the discussion here is really about two
different types of systems - mainstream ongrid PV, and small scale (and a
relatively small market) offgrid PV. It's really tough to design a small
offgrid system (especially DC coupled) with rapid shutdown. I think it's
just a case that the market is so small that the manufactures aren't
focusing their products on it. Our business doesn't do much offgrid, so I'm
not familiar with the products but understand the difficulty. For ongrid PV
with or without energy storage, I still argue that MPLE or microinverters
are 100% the now and future, and fighting against that is a losing battle.

I think we should see more and more offgrid ability coming from the big
players SolarEdge, Tesla, (maybe Enphase) etc which will all be easy to
pair with rapid shutdown enabled PV.

August




On Thu, Apr 30, 2020 at 7:12 AM Ray  wrote:

> Hi Jerry;
>
> This isn't about us not being willing to learn the tech.  All of us are
> constantly learning about new code changes, new inverters, and solar
> modules that change specs every few months.  We are voluntarily adopting
> new technology (like Lithium Ion batteries) when that technology is cost
> effective and reliable.
>
> To continue your smart phone analogy, the current situation is like
> forcing people in the country to give up their hard lines, when their is
> only spotty 3G service available in their area.  Its not that we are
> Luddites; the equipment is still not quite ready for prime time.   Having
> some basic exemptions for small, lower voltage systems off grid is not
> unreasonable.
>
> Ray Walters
> Remote Solar
> 303 505-8760
>
> On 4/30/20 2:33 AM, Jerry Shafer wrote:
>
> Wrenches
> We are taking two very different issues and mixing them together. RSD and
> Arc-fault are different, arc fault will and does prevent fires, RSD was
> brought out of the need to vent a roof that even with the meter pulled have
> 500 volts and resulted shocks to fire fighters by cutting into roofs or
> nearby conduite. This is fact not conjecture.
> Arc fault is a fire preventer but requires nothing on the roof when using
> string level inverters. Now both RSD and arc-fault in off grid increase the
> complexity but the new charge controllers fit the arc and Tigo fixes the
> RSD issues.
> I know everyone of you learned to use a smart phone and can now adapt
> again to this new tech, we have to be leaders in this industry and not well
> you know.
> Jerry
> NABCEP PV Inspector.
> Been in this industry since 1978
>
> On Wed, Apr 29, 2020, 6:57 PM Jay  wrote:
>
>> Hi Drake
>>
>> I will disagree, there have been many roof top fires.
>>
>> But regardless we have to do these new regulations and I for one welcome
>> the safety.
>>
>> The main issue is accessing the faulty/suspect component under the module
>> possibly requiring removing multiple modules, a slow and expensive process.
>>
>> My technique is to install the MLPE at the edges of the array, using wire
>> extensions. That way at most I have to remove a single module.  And Im
>> working on a drop bracket which would allow better cooling and easier
>> access without module removal to the MLPE, greatly reducing time to swap.
>>
>> Jay
>>
>> Peltz Power.
>>
>>
>>
>>
>>
>> On Apr 29, 2020, at 7:59 AM, drake.chamber...@redwoodalliance.org wrote:
>>
>> 
>>
>> Clearly, rapid shutdown increases cost and reduces reliability. Given the
>> excellent safety record of PV, prior to rapid shutdown being required, it
>> is unnecessary. The few anecdotal incidents of PV fires were not enough to
>> justify the requirement, especially on smaller systems.
>>
>> According to a friend who worked for a local installation company that
>> went under, a big part of the reason for their failure was the chronic
>> replacement of microinverters and optimizers.
>>
>> What steps can be taken to create some balance in the rapid shutdown
>> requirements that are in the NEC?
>>
>>
>> ---
>>
>>
>>
>> On 2020-04-29 07:27, Sky Sims wrote:
>>
>> So far rapid shutdown has been a nightmare. It's added a lot of cost for
>> no measurable benefit.
>> Using always off devices like midnight solar and Tigo makes it impossible
>> to test open circuit voltages. Which opens the door to tons of problems
>> when commissioning systems.
>> Also we've been trying out midnight Solar's product and have had an
>> absurd failure rate. Which means lots of truck rolls and troubleshooting
>> and system downtime. They send replacement product but they aren't paying
>> for the lost weeks of productivity.
>> We have Tigo product in hand and are deciding which project to try it on.
>> But our big concern about using it is not only the inability to confirm
>> open circuit voltage of the strings but also the way panels bypass if the
>> device doesn't allow the panel to connect properly. Both of these features
>> are a recipe for problems and potential troubleshooting nightmares. The
>> warranty from Tigo doesn't cover our expense if 

Re: [RE-wrenches] Rapid Shutdown Compliance

[Brian Mehalic]

Deadline for 2023 NEC® public input is in September. 

Brian

> On Apr 30, 2020, at 7:12 AM, Ray  wrote:
> 
> 
> Hi Jerry;
> 
> This isn't about us not being willing to learn the tech.  All of us are 
> constantly learning about new code changes, new inverters, and solar modules 
> that change specs every few months.  We are voluntarily adopting new 
> technology (like Lithium Ion batteries) when that technology is cost 
> effective and reliable.  
> 
> To continue your smart phone analogy, the current situation is like forcing 
> people in the country to give up their hard lines, when their is only spotty 
> 3G service available in their area.  Its not that we are Luddites; the 
> equipment is still not quite ready for prime time.   Having some basic 
> exemptions for small, lower voltage systems off grid is not unreasonable.
> 
> Ray Walters
> Remote Solar
> 303 505-8760
>> On 4/30/20 2:33 AM, Jerry Shafer wrote:
>> Wrenches
>> We are taking two very different issues and mixing them together. RSD and 
>> Arc-fault are different, arc fault will and does prevent fires, RSD was 
>> brought out of the need to vent a roof that even with the meter pulled have 
>> 500 volts and resulted shocks to fire fighters by cutting into roofs or 
>> nearby conduite. This is fact not conjecture.
>> Arc fault is a fire preventer but requires nothing on the roof when using 
>> string level inverters. Now both RSD and arc-fault in off grid increase the 
>> complexity but the new charge controllers fit the arc and Tigo fixes the RSD 
>> issues. 
>> I know everyone of you learned to use a smart phone and can now adapt again 
>> to this new tech, we have to be leaders in this industry and not well you 
>> know.
>> Jerry
>> NABCEP PV Inspector.
>> Been in this industry since 1978 
>> 
>> On Wed, Apr 29, 2020, 6:57 PM Jay  wrote:
>>> Hi Drake 
>>> 
>>> I will disagree, there have been many roof top fires. 
>>> 
>>> But regardless we have to do these new regulations and I for one welcome 
>>> the safety. 
>>> 
>>> The main issue is accessing the faulty/suspect component under the module 
>>> possibly requiring removing multiple modules, a slow and expensive process. 
>>> 
>>> My technique is to install the MLPE at the edges of the array, using wire 
>>> extensions. That way at most I have to remove a single module.  And Im 
>>> working on a drop bracket which would allow better cooling and easier 
>>> access without module removal to the MLPE, greatly reducing time to swap. 
>>> 
>>> Jay
>>> 
>>> Peltz Power. 
>>> 
>>> 
>>> 
>>> 
>>> 
 On Apr 29, 2020, at 7:59 AM, drake.chamber...@redwoodalliance.org wrote:
 
 
 Clearly, rapid shutdown increases cost and reduces reliability. Given the 
 excellent safety record of PV, prior to rapid shutdown being required, it 
 is unnecessary. The few anecdotal incidents of PV fires were not enough to 
 justify the requirement, especially on smaller systems.
 
 According to a friend who worked for a local installation company that 
 went under, a big part of the reason for their failure was the chronic 
 replacement of microinverters and optimizers.
 
 What steps can be taken to create some balance in the rapid shutdown 
 requirements that are in the NEC?
 
 
 
 ---
  
 
 
> On 2020-04-29 07:27, Sky Sims wrote:
> 
> So far rapid shutdown has been a nightmare. It's added a lot of cost for 
> no measurable benefit.
> Using always off devices like midnight solar and Tigo makes it impossible 
> to test open circuit voltages. Which opens the door to tons of problems 
> when commissioning systems. 
> Also we've been trying out midnight Solar's product and have had an 
> absurd failure rate. Which means lots of truck rolls and troubleshooting 
> and system downtime. They send replacement product but they aren't paying 
> for the lost weeks of productivity.
> We have Tigo product in hand and are deciding which project to try it on. 
> But our big concern about using it is not only the inability to confirm 
> open circuit voltage of the strings but also the way panels bypass if the 
> device doesn't allow the panel to connect properly. Both of these 
> features are a recipe for problems and potential troubleshooting 
> nightmares. The warranty from Tigo doesn't cover our expense if the 
> product fails. And that's really what our reservations about the product 
> boil down to right now. If we're on a job with 50 units and one fails, 
> the contractor or the homeowner will be the ones eating the expense of 
> finding it and replacing it. There has to be a better option. 
> 
> Sky Sims
> Https://EcologicalSystems.biz
> 
>> On Apr 28, 2020, at 7:46 PM, Corey Shalanski  wrote:
>> 
>> Now that 690.12 of the NEC 2017 has been in effect for several years, I 
>> am curious how designers and installers are meeting 

Re: [RE-wrenches] Rapid Shutdown Compliance

[Ray]

Hi Jerry;

This isn't about us not being willing to learn the tech.  All of us are 
constantly learning about new code changes, new inverters, and solar 
modules that change specs every few months.  We are voluntarily adopting 
new technology (like Lithium Ion batteries) when that technology is cost 
effective and reliable.


To continue your smart phone analogy, the current situation is like 
forcing people in the country to give up their hard lines, when their is 
only spotty 3G service available in their area.  Its not that we are 
Luddites; the equipment is still not quite ready for prime time.   
Having some basic exemptions for small, lower voltage systems off grid 
is not unreasonable.


Ray Walters
Remote Solar
303 505-8760

On 4/30/20 2:33 AM, Jerry Shafer wrote:

Wrenches
We are taking two very different issues and mixing them together. RSD 
and Arc-fault are different, arc fault will and does prevent fires, 
RSD was brought out of the need to vent a roof that even with the 
meter pulled have 500 volts and resulted shocks to fire fighters by 
cutting into roofs or nearby conduite. This is fact not conjecture.
Arc fault is a fire preventer but requires nothing on the roof when 
using string level inverters. Now both RSD and arc-fault in off grid 
increase the complexity but the new charge controllers fit the arc and 
Tigo fixes the RSD issues.
I know everyone of you learned to use a smart phone and can now adapt 
again to this new tech, we have to be leaders in this industry and not 
well you know.

Jerry
NABCEP PV Inspector.
Been in this industry since 1978

On Wed, Apr 29, 2020, 6:57 PM Jay > wrote:


Hi Drake

I will disagree, there have been many roof top fires.

But regardless we have to do these new regulations and I for one
welcome the safety.

The main issue is accessing the faulty/suspect component under the
module possibly requiring removing multiple modules, a slow and
expensive process.

My technique is to install the MLPE at the edges of the array,
using wire extensions. That way at most I have to remove a single
module.  And Im working on a drop bracket which would allow better
cooling and easier access without module removal to the MLPE,
greatly reducing time to swap.

Jay

Peltz Power.






On Apr 29, 2020, at 7:59 AM, drake.chamber...@redwoodalliance.org
 wrote:



Clearly, rapid shutdown increases cost and reduces reliability.
Given the excellent safety record of PV, prior to rapid shutdown
being required, it is unnecessary. The few anecdotal incidents of
PV fires were not enough to justify the requirement, especially
on smaller systems.

According to a friend who worked for a local installation company
that went under, a big part of the reason for their failure was
the chronic replacement of microinverters and optimizers.

What steps can be taken to create some balance in the rapid
shutdown requirements that are in the NEC?


---


On 2020-04-29 07:27, Sky Sims wrote:


So far rapid shutdown has been a nightmare. It's added a lot of
cost for no measurable benefit.
Using always off devices like midnight solar and Tigo makes it
impossible to test open circuit voltages. Which opens the door
to tons of problems when commissioning systems.
Also we've been trying out midnight Solar's product and have had
an absurd failure rate. Which means lots of truck rolls and
troubleshooting and system downtime. They send replacement
product but they aren't paying for the lost weeks of productivity.
We have Tigo product in hand and are deciding which project to
try it on. But our big concern about using it is not only the
inability to confirm open circuit voltage of the strings but
also the way panels bypass if the device doesn't allow the panel
to connect properly. Both of these features are a recipe for
problems and potential troubleshooting nightmares. The warranty
from Tigo doesn't cover our expense if the product fails. And
that's really what our reservations about the product boil down
to right now. If we're on a job with 50 units and one fails, the
contractor or the homeowner will be the ones eating the expense
of finding it and replacing it. There has to be a better option.

Sky Sims
Https://EcologicalSystems.biz


On Apr 28, 2020, at 7:46 PM, Corey Shalanski
mailto:coreso...@gmail.com>> wrote:

Now that 690.12 of the /NEC/ 2017 has been in effect for
several years, I am curious how designers and installers are
meeting the associated requirements with string inverter-based
systems (*not* considering microinverters or DC optimizers). I
am generally a fan of the KISS principle, and as best I can
determine the /Tigo/ TS4-F device is one of the simplest
options currently available 

Re: [RE-wrenches] Rapid Shutdown Compliance

[Jerry Shafer]

Wrenches
We are taking two very different issues and mixing them together. RSD and
Arc-fault are different, arc fault will and does prevent fires, RSD was
brought out of the need to vent a roof that even with the meter pulled have
500 volts and resulted shocks to fire fighters by cutting into roofs or
nearby conduite. This is fact not conjecture.
Arc fault is a fire preventer but requires nothing on the roof when using
string level inverters. Now both RSD and arc-fault in off grid increase the
complexity but the new charge controllers fit the arc and Tigo fixes the
RSD issues.
I know everyone of you learned to use a smart phone and can now adapt again
to this new tech, we have to be leaders in this industry and not well you
know.
Jerry
NABCEP PV Inspector.
Been in this industry since 1978

On Wed, Apr 29, 2020, 6:57 PM Jay  wrote:

> Hi Drake
>
> I will disagree, there have been many roof top fires.
>
> But regardless we have to do these new regulations and I for one welcome
> the safety.
>
> The main issue is accessing the faulty/suspect component under the module
> possibly requiring removing multiple modules, a slow and expensive process.
>
> My technique is to install the MLPE at the edges of the array, using wire
> extensions. That way at most I have to remove a single module.  And Im
> working on a drop bracket which would allow better cooling and easier
> access without module removal to the MLPE, greatly reducing time to swap.
>
> Jay
>
> Peltz Power.
>
>
>
>
>
> On Apr 29, 2020, at 7:59 AM, drake.chamber...@redwoodalliance.org wrote:
>
> 
>
> Clearly, rapid shutdown increases cost and reduces reliability. Given the
> excellent safety record of PV, prior to rapid shutdown being required, it
> is unnecessary. The few anecdotal incidents of PV fires were not enough to
> justify the requirement, especially on smaller systems.
>
> According to a friend who worked for a local installation company that
> went under, a big part of the reason for their failure was the chronic
> replacement of microinverters and optimizers.
>
> What steps can be taken to create some balance in the rapid shutdown
> requirements that are in the NEC?
>
>
> ---
>
>
>
> On 2020-04-29 07:27, Sky Sims wrote:
>
> So far rapid shutdown has been a nightmare. It's added a lot of cost for
> no measurable benefit.
> Using always off devices like midnight solar and Tigo makes it impossible
> to test open circuit voltages. Which opens the door to tons of problems
> when commissioning systems.
> Also we've been trying out midnight Solar's product and have had an absurd
> failure rate. Which means lots of truck rolls and troubleshooting and
> system downtime. They send replacement product but they aren't paying for
> the lost weeks of productivity.
> We have Tigo product in hand and are deciding which project to try it on.
> But our big concern about using it is not only the inability to confirm
> open circuit voltage of the strings but also the way panels bypass if the
> device doesn't allow the panel to connect properly. Both of these features
> are a recipe for problems and potential troubleshooting nightmares. The
> warranty from Tigo doesn't cover our expense if the product fails. And
> that's really what our reservations about the product boil down to right
> now. If we're on a job with 50 units and one fails, the contractor or the
> homeowner will be the ones eating the expense of finding it and replacing
> it. There has to be a better option.
>
> Sky Sims
> Https://EcologicalSystems.biz
>
> On Apr 28, 2020, at 7:46 PM, Corey Shalanski  wrote:
>
> Now that 690.12 of the *NEC* 2017 has been in effect for several years, I
> am curious how designers and installers are meeting the associated
> requirements with string inverter-based systems (*not* considering
> microinverters or DC optimizers). I am generally a fan of the KISS
> principle, and as best I can determine the *Tigo* TS4-F device is one of
> the simplest options currently available on the market. What are others
> finding?
>
> I'd love to hear about favored options for complying with rapid shutdown.
> Any success stories? or better yet, any early failures?
>
> --
> Corey Shalanski
> Jah Light Solar
> Portland, Jamaica
> ___
> List sponsored by Redwood Alliance
>
> List Address: RE-wrenches@lists.re-wrenches.org
>
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Re: [RE-wrenches] Rapid Shutdown Compliance

[drake . chamberlin]

Rapid Shutdown does not prevent fires; it was originally drafted to
allow firefighters to vent a roof without being hindered by energized PV
arrays. This rule was expanded to include other DC wiring from PV
sources. 


As for PV safety, I'd like to see some significant, statistical evidence
that shows there is a major fire danger from PV relative to other
sources. A fire from a solar array gets a lot more press than one from a
gas leak, bad wiring or an ash tray emptied into a wastepaper basket. 


Large public buildings should have all the protection that is available.
Does one size fit all? 


Would it be reasonable to allow residential installations under 12 kW,
with 1/4 of the roof adjacent to the array available for venting, to be
excepted from 690.12? What about sparsely occupied commercial buildings
with ample roof area open for ventilation?   


Many of us have chosen to work with renewable energy technology to
lessen the harms caused by fossil fuel extraction and combustion. The
need for non-carbon based energy sources has become extremely clear. 


The old string inverters still chug along year after year, with little
or no maintenance. Someone must pay for the ongoing maintenance of
module level electronics. Dependable string inverter systems should be
allowed unless statically significant danger can be demonstrated. 


Drake

---

On 2020-04-29 16:01, Jason Szumlanski wrote:

I have been to several PV fires for string inverter systems, both commercial and residential, and have seen many DC systems at serious risk of fires or in various stages of melted insulation and connectors. Most of these systems have exhibited good to excellent workmanship. Things just went wrong. Some were traceable to animal damage, wind, or other unmitigated factors, and some were unexplained. I disagree that there isn't justification for rapid shutdown.  

In my opinion, what we need is some additional innovation and competition in the MLPE space. Reliability is clearly a key factor, but there is no denying that MLPE has added safety benefits among other benefits. And if you do enough volume and set up your business for efficiency (standardization of product offerings), MLPE isn't much more expensive. It becomes a negligible cost relative to the benefit. The value proposition is easy to convey. There are limits to this, but for the majority of residential and small commercial installations, MLPE has become the de facto standard around here. String inverters are dinos, and replacing 8-12 year old transformer based inverters is many times more annoying than some MLPE swaps. I will admit that the roofs around here are pretty easy to walk, so that is a factor that might not apply to you. 

If you go under due to manufacturer product failures, you are not writing your contracts right or not charging enough for service issues beyond your control. I believe that's a red herring. You might suffer some reputation damage, but for someone that has been installing MLPE for over a decade, that is totally manageable. Consumers find a service call to replace MLPE a LOT more palatable than a surprise inverter replacement that could cost thousands of dollars. People just don't plan for that. 

Regarding rapid shutdown devices, I have also come across a few that "someone" has bypassed around here. I don't know if they were never installed properly or disabled/bypassed due to failure. It seemed suspicious to me at the time. I remember that it made me wonder what good is a rapid shutdown device if it is easily defeated? That's another argument for MLPE. It has pretty failsafe MLPE functionality. 

Jason Szumlanski 
Florida Solar Design Group 

On Wed, Apr 29, 2020 at 10:59 AM  wrote: 

Clearly, rapid shutdown increases cost and reduces reliability. Given the excellent safety record of PV, prior to rapid shutdown being required, it is unnecessary. The few anecdotal incidents of PV fires were not enough to justify the requirement, especially on smaller systems. 

According to a friend who worked for a local installation company that went under, a big part of the reason for their failure was the chronic replacement of microinverters and optimizers. 

What steps can be taken to create some balance in the rapid shutdown requirements that are in the NEC? 


---

On 2020-04-29 07:27, Sky Sims wrote: 

So far rapid shutdown has been a nightmare. It's added a lot of cost for no measurable benefit. 
Using always off devices like midnight solar and Tigo makes it impossible to test open circuit voltages. Which opens the door to tons of problems when commissioning systems.  
Also we've been trying out midnight Solar's product and have had an absurd failure rate. Which means lots of truck rolls and troubleshooting and system downtime. They send replacement product but they aren't paying for the lost weeks of productivity. 
We have Tigo product in hand and are deciding which project to try it on. But our big concern about using it is not only the 

Re: [RE-wrenches] Rapid Shutdown Compliance

[Jason Szumlanski]

"Rapid Shutdown does not prevent fires."

Not true. If the effect of RS is to steer the market to MLPE, I believe it
has a significant impact on reducing fire risk. As one who has watched a DC
conductor fire smolder out of control, I am sold on an AC module or
microinverter architecture. While RS on a DC array doesn't necessarily
reduce fire risk within the array, it still has the potential to reduce
severity and spread. Nothing is going to prevent all fires. I get that.
We're talking about risk mitigation when it comes to RS.

As for "dependable string inverters," the one dependable feature is failure
at least once in the module lifetime, accompanied by a shocking repair bill.

I'm not a shiny object following kind of guy, but the writing is on the
wall. MLPE is the future. Modular, serviceable, disposable if you will.
Like it or not, Edison is going to lose this battle to Tesla (Tom vs
Nikola). And I live less than 5 minutes away from Tommy E's winter home in
Fort Myers, FL. And I "grew up" in the industry living off-grid in DC
power. But AC distribution wins for safety at various scales.






On Wed, Apr 29, 2020, 9:42 PM  wrote:

> Rapid Shutdown does not prevent fires; it was originally drafted to allow
> firefighters to vent a roof without being hindered by energized PV arrays.
> This rule was expanded to include other DC wiring from PV sources.
>
> As for PV safety, I’d like to see some significant, statistical evidence
> that shows there is a major fire danger from PV relative to other sources.
> A fire from a solar array gets a lot more press than one from a gas leak,
> bad wiring or an ash tray emptied into a wastepaper basket.
>
> Large public buildings should have all the protection that is available.
> Does one size fit all?
>
> Would it be reasonable to allow residential installations under 12 kW,
> with 1/4 of the roof adjacent to the array available for venting, to be
> excepted from 690.12? What about sparsely occupied commercial buildings
> with ample roof area open for ventilation?
>
> Many of us have chosen to work with renewable energy technology to lessen
> the harms caused by fossil fuel extraction and combustion. The need for
> non-carbon based energy sources has become extremely clear.
>
> The old string inverters still chug along year after year, with little or
> no maintenance. Someone must pay for the ongoing maintenance of module
> level electronics. Dependable string inverter systems should be allowed
> unless statically significant danger can be demonstrated.
>
> Drake
> ---
>
>
>
> On 2020-04-29 16:01, Jason Szumlanski wrote:
>
> I have been to several PV fires for string inverter systems, both
> commercial and residential, and have seen many DC systems at serious risk
> of fires or in various stages of melted insulation and connectors. Most of
> these systems have exhibited good to excellent workmanship. Things just
> went wrong. Some were traceable to animal damage, wind, or other
> unmitigated factors, and some were unexplained. I disagree that there isn't
> justification for rapid shutdown.
>
> In my opinion, what we need is some additional innovation and competition
> in the MLPE space. Reliability is clearly a key factor, but there is no
> denying that MLPE has added safety benefits among other benefits. And if
> you do enough volume and set up your business for efficiency
> (standardization of product offerings), MLPE isn't much more expensive. It
> becomes a negligible cost relative to the benefit. The value proposition is
> easy to convey. There are limits to this, but for the majority of
> residential and small commercial installations, MLPE has become the de
> facto standard around here. String inverters are dinos, and replacing 8-12
> year old transformer based inverters is many times more annoying than some
> MLPE swaps. I will admit that the roofs around here are pretty easy to
> walk, so that is a factor that might not apply to you.
>
> If you go under due to manufacturer product failures, you are not writing
> your contracts right or not charging enough for service issues beyond your
> control. I believe that's a red herring. You might suffer some reputation
> damage, but for someone that has been installing MLPE for over a decade,
> that is totally manageable. Consumers find a service call to replace MLPE a
> LOT more palatable than a surprise inverter replacement that could cost
> thousands of dollars. People just don't plan for that.
>
> Regarding rapid shutdown devices, I have also come across a few that
> "someone" has bypassed around here. I don't know if they were never
> installed properly or disabled/bypassed due to failure. It seemed
> suspicious to me at the time. I remember that it made me wonder what good
> is a rapid shutdown device if it is easily defeated? That's another
> argument for MLPE. It has pretty failsafe MLPE functionality.
>
> Jason Szumlanski
> Florida Solar Design Group
>
>
>
> On Wed, Apr 29, 2020 at 10:59 AM 
> wrote:
>
> 

Re: [RE-wrenches] Rapid Shutdown Compliance

[Jason Szumlanski]

I have been to several PV fires for string inverter systems, both
commercial and residential, and have seen many DC systems at serious risk
of fires or in various stages of melted insulation and connectors. Most of
these systems have exhibited good to excellent workmanship. Things just
went wrong. Some were traceable to animal damage, wind, or other
unmitigated factors, and some were unexplained. I disagree that there isn't
justification for rapid shutdown.

In my opinion, what we need is some additional innovation and competition
in the MLPE space. Reliability is clearly a key factor, but there is no
denying that MLPE has added safety benefits among other benefits. And if
you do enough volume and set up your business for efficiency
(standardization of product offerings), MLPE isn't much more expensive. It
becomes a negligible cost relative to the benefit. The value proposition is
easy to convey. There are limits to this, but for the majority of
residential and small commercial installations, MLPE has become the de
facto standard around here. String inverters are dinos, and replacing 8-12
year old transformer based inverters is many times more annoying than some
MLPE swaps. I will admit that the roofs around here are pretty easy to
walk, so that is a factor that might not apply to you.

If you go under due to manufacturer product failures, you are not writing
your contracts right or not charging enough for service issues beyond your
control. I believe that's a red herring. You might suffer some reputation
damage, but for someone that has been installing MLPE for over a decade,
that is totally manageable. Consumers find a service call to replace MLPE a
LOT more palatable than a surprise inverter replacement that could cost
thousands of dollars. People just don't plan for that.

Regarding rapid shutdown devices, I have also come across a few that
"someone" has bypassed around here. I don't know if they were never
installed properly or disabled/bypassed due to failure. It seemed
suspicious to me at the time. I remember that it made me wonder what good
is a rapid shutdown device if it is easily defeated? That's another
argument for MLPE. It has pretty failsafe MLPE functionality.

Jason Szumlanski
Florida Solar Design Group



On Wed, Apr 29, 2020 at 10:59 AM 
wrote:

> Clearly, rapid shutdown increases cost and reduces reliability. Given the
> excellent safety record of PV, prior to rapid shutdown being required, it
> is unnecessary. The few anecdotal incidents of PV fires were not enough to
> justify the requirement, especially on smaller systems.
>
> According to a friend who worked for a local installation company that
> went under, a big part of the reason for their failure was the chronic
> replacement of microinverters and optimizers.
>
> What steps can be taken to create some balance in the rapid shutdown
> requirements that are in the NEC?
>
>
> ---
>
>
>
> On 2020-04-29 07:27, Sky Sims wrote:
>
> So far rapid shutdown has been a nightmare. It's added a lot of cost for
> no measurable benefit.
> Using always off devices like midnight solar and Tigo makes it impossible
> to test open circuit voltages. Which opens the door to tons of problems
> when commissioning systems.
> Also we've been trying out midnight Solar's product and have had an absurd
> failure rate. Which means lots of truck rolls and troubleshooting and
> system downtime. They send replacement product but they aren't paying for
> the lost weeks of productivity.
> We have Tigo product in hand and are deciding which project to try it on.
> But our big concern about using it is not only the inability to confirm
> open circuit voltage of the strings but also the way panels bypass if the
> device doesn't allow the panel to connect properly. Both of these features
> are a recipe for problems and potential troubleshooting nightmares. The
> warranty from Tigo doesn't cover our expense if the product fails. And
> that's really what our reservations about the product boil down to right
> now. If we're on a job with 50 units and one fails, the contractor or the
> homeowner will be the ones eating the expense of finding it and replacing
> it. There has to be a better option.
>
> Sky Sims
> Https://EcologicalSystems.biz
>
> On Apr 28, 2020, at 7:46 PM, Corey Shalanski  wrote:
>
> Now that 690.12 of the *NEC* 2017 has been in effect for several years, I
> am curious how designers and installers are meeting the associated
> requirements with string inverter-based systems (*not* considering
> microinverters or DC optimizers). I am generally a fan of the KISS
> principle, and as best I can determine the *Tigo* TS4-F device is one of
> the simplest options currently available on the market. What are others
> finding?
>
> I'd love to hear about favored options for complying with rapid shutdown.
> Any success stories? or better yet, any early failures?
>
> --
> Corey Shalanski
> Jah Light Solar
> Portland, Jamaica
> 

Re: [RE-wrenches] Rapid Shutdown Compliance

[Darryl Thayer]

my two cents worth, 690.11 says turn off from all arcs, that means serial
and parallel
that means module lwevel shutdown
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Re: [RE-wrenches] Rapid Shutdown Compliance

[Ray]

I agree, 690.12 should have exemptions for lower voltage, lower power 
systems, and shorter runs; especially off grid.  10 years ago, I was 
promoting some type of remote controlled disconnect at the array, but 
that was for voltages over 400v, with unprotected conduit runs over a 
100 ft long, on systems over 10 kW.


For off grid where reliability is the number one safety issue, we've 
gone back to pole mounts to avoid 690.12.  If the temperature goes below 
zero, and the customer is snow bound, having the Rapid disconnect trip 
off is NOT creating a safer situation.  They need heat, unfrozen water 
supply, and communications.    Rural VFDs are not going to usually even 
get up on the roof anyway.  That's a scenario for in town, when they can 
respond in less than 10 minutes.


Actually for residential systems in rural areas, the only person that is 
going to get hurt on the roof is the customer trying to reset the Rapid 
Disconnect, not the Fire Department.  Maybe the NEC task groups will 
finally see that fire fighter safety needs to be balanced with the 
safety of the people they are trying to protect. I hope that the NEC 
could reach this conclusion before an untrained home owner breaks their 
neck.


Ray Walters
Remote Solar
303 505-8760

On 4/29/20 10:17 AM, drake.chamber...@redwoodalliance.org wrote:


Clearly, rapid shutdown increases cost and reduces reliability. Given 
the excellent safety record of PV, prior to rapid shutdown being 
required, it is unnecessary. The few anecdotal incidents of PV fires 
were not enough to justify the requirement, especially on smaller 
systems.


According to a friend who worked for a local installation company that 
went under, a big part of the reason for their failure was the chronic 
replacement of microinverters and optimizers.


What steps can be taken to create some balance in the rapid shutdown 
requirements that are in the NEC?



---


On 2020-04-29 07:27, Sky Sims wrote:

So far rapid shutdown has been a nightmare. It's added a lot of cost 
for no measurable benefit.
Using always off devices like midnight solar and Tigo makes it 
impossible to test open circuit voltages. Which opens the door to 
tons of problems when commissioning systems.
Also we've been trying out midnight Solar's product and have had an 
absurd failure rate. Which means lots of truck rolls and 
troubleshooting and system downtime. They send replacement product 
but they aren't paying for the lost weeks of productivity.
We have Tigo product in hand and are deciding which project to try it 
on. But our big concern about using it is not only the inability to 
confirm open circuit voltage of the strings but also the way panels 
bypass if the device doesn't allow the panel to connect properly. 
Both of these features are a recipe for problems and potential 
troubleshooting nightmares. The warranty from Tigo doesn't cover our 
expense if the product fails. And that's really what our reservations 
about the product boil down to right now. If we're on a job with 50 
units and one fails, the contractor or the homeowner will be the ones 
eating the expense of finding it and replacing it. There has to be a 
better option.


Sky Sims
Https://EcologicalSystems.biz

On Apr 28, 2020, at 7:46 PM, Corey Shalanski  
wrote:


Now that 690.12 of the /NEC/ 2017 has been in effect for several 
years, I am curious how designers and installers are meeting the 
associated requirements with string inverter-based systems (*not* 
considering microinverters or DC optimizers). I am generally a fan 
of the KISS principle, and as best I can determine the /Tigo/ TS4-F 
device is one of the simplest options currently available on the 
market. What are others finding?
I'd love to hear about favored options for complying with rapid 
shutdown. Any success stories? or better yet, any early failures?

--
Corey Shalanski
Jah Light Solar
Portland, Jamaica
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Re: [RE-wrenches] Rapid Shutdown Compliance

[Dave Angelini Offgrid Solar]

My 2 cents are related to the very few times I have had to do RS for
offgrid. My advice is to install whatever the inspector wants, assuming he
can't be convinced of the mindless requirement. Complete the installation.
Do the right thing after by abandoning it. Have the client remove the RS
signing so fire folks do not get misled. 

I am testing the Schneider RS
here on one array, but XW is out of the loop. Just logging. 

Dave Angelini
Offgrid Solar
"we go where powerlines
don't"
http://members.sti.net/offgridsolar/ [1]
e-mail offgridso...@sti.net
[2]
text 209 813 0060

On Wed, 29 Apr 2020 10:17:33 -0400,
drake.chamber...@redwoodalliance.org wrote:  

Clearly, rapid shutdown
increases cost and reduces reliability. Given the excellent safety record
of PV, prior to rapid shutdown being required, it is unnecessary. The few
anecdotal incidents of PV fires were not enough to justify the requirement,
especially on smaller systems. 

According to a friend who worked for a
local installation company that went under, a big part of the reason for
their failure was the chronic replacement of microinverters and optimizers.


What steps can be taken to create some balance in the rapid shutdown
requirements that are in the NEC? 

  ---

On 2020-04-29 07:27, Sky Sims
wrote:   So far rapid shutdown has been a nightmare. It's added a lot of
cost for no measurable benefit. Using always off devices like midnight
solar and Tigo makes it impossible to test open circuit voltages. Which
opens the door to tons of problems when commissioning systems.  Also we've
been trying out midnight Solar's product and have had an absurd failure
rate. Which means lots of truck rolls and troubleshooting and system
downtime. They send replacement product but they aren't paying for the lost
weeks of productivity. We have Tigo product in hand and are deciding which
project to try it on. But our big concern about using it is not only the
inability to confirm open circuit voltage of the strings but also the way
panels bypass if the device doesn't allow the panel to connect properly.
Both of these features are a recipe for problems and potential
troubleshooting nightmares. The warranty from Tigo doesn't cover our
expense if the product fails. And that's really what our reservations about
the product boil down to right now. If we're on a job with 50 units and one
fails, the contractor or the homeowner will be the ones eating the expense
of finding it and replacing it. There has to be a better option.  
 Sky
Sims Https://EcologicalSystems.biz  
 On Apr 28, 2020, at 7:46 PM, Corey
Shalanski  wrote:

Now that 690.12 of the _NEC_ 2017 has been in effect
for several years, I am curious how designers and installers are meeting
the associated requirements with string inverter-based systems (*not*
considering microinverters or DC optimizers). I am generally a fan of the
KISS principle, and as best I can determine the _Tigo_ TS4-F device is one
of the simplest options currently available on the market. What are others
finding?   I'd love to hear about favored options for complying with rapid
shutdown. Any success stories? or better yet, any early failures?   --
Corey Shalanski Jah Light Solar Portland, Jamaica 
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Re: [RE-wrenches] Rapid Shutdown Compliance

[Jay]

Hi Drake 

I will disagree, there have been many roof top fires. 

But regardless we have to do these new regulations and I for one welcome the 
safety. 

The main issue is accessing the faulty/suspect component under the module 
possibly requiring removing multiple modules, a slow and expensive process. 

My technique is to install the MLPE at the edges of the array, using wire 
extensions. That way at most I have to remove a single module.  And Im working 
on a drop bracket which would allow better cooling and easier access without 
module removal to the MLPE, greatly reducing time to swap. 

Jay

Peltz Power. 





> On Apr 29, 2020, at 7:59 AM, drake.chamber...@redwoodalliance.org wrote:
> 
> 
> Clearly, rapid shutdown increases cost and reduces reliability. Given the 
> excellent safety record of PV, prior to rapid shutdown being required, it is 
> unnecessary. The few anecdotal incidents of PV fires were not enough to 
> justify the requirement, especially on smaller systems.
> 
> According to a friend who worked for a local installation company that went 
> under, a big part of the reason for their failure was the chronic replacement 
> of microinverters and optimizers.
> 
> What steps can be taken to create some balance in the rapid shutdown 
> requirements that are in the NEC?
> 
> 
> 
> ---
>  
> 
> 
>> On 2020-04-29 07:27, Sky Sims wrote:
>> 
>> So far rapid shutdown has been a nightmare. It's added a lot of cost for no 
>> measurable benefit.
>> Using always off devices like midnight solar and Tigo makes it impossible to 
>> test open circuit voltages. Which opens the door to tons of problems when 
>> commissioning systems. 
>> Also we've been trying out midnight Solar's product and have had an absurd 
>> failure rate. Which means lots of truck rolls and troubleshooting and system 
>> downtime. They send replacement product but they aren't paying for the lost 
>> weeks of productivity.
>> We have Tigo product in hand and are deciding which project to try it on. 
>> But our big concern about using it is not only the inability to confirm open 
>> circuit voltage of the strings but also the way panels bypass if the device 
>> doesn't allow the panel to connect properly. Both of these features are a 
>> recipe for problems and potential troubleshooting nightmares. The warranty 
>> from Tigo doesn't cover our expense if the product fails. And that's really 
>> what our reservations about the product boil down to right now. If we're on 
>> a job with 50 units and one fails, the contractor or the homeowner will be 
>> the ones eating the expense of finding it and replacing it. There has to be 
>> a better option. 
>> 
>> Sky Sims
>> Https://EcologicalSystems.biz
>> 
>>> On Apr 28, 2020, at 7:46 PM, Corey Shalanski  wrote:
>>> 
>>> Now that 690.12 of the NEC 2017 has been in effect for several years, I am 
>>> curious how designers and installers are meeting the associated 
>>> requirements with string inverter-based systems (*not* considering 
>>> microinverters or DC optimizers). I am generally a fan of the KISS 
>>> principle, and as best I can determine the Tigo TS4-F device is one of the 
>>> simplest options currently available on the market. What are others finding?
>>>  
>>> I'd love to hear about favored options for complying with rapid shutdown. 
>>> Any success stories? or better yet, any early failures?
>>>  
>>> --
>>> Corey Shalanski
>>> Jah Light Solar
>>> Portland, Jamaica
>>> ___
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>>> List Address: RE-wrenches@lists.re-wrenches.org
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Re: [RE-wrenches] Rapid Shutdown Compliance

[drake . chamberlin]

Clearly, rapid shutdown increases cost and reduces reliability. Given
the excellent safety record of PV, prior to rapid shutdown being
required, it is unnecessary. The few anecdotal incidents of PV fires
were not enough to justify the requirement, especially on smaller
systems. 


According to a friend who worked for a local installation company that
went under, a big part of the reason for their failure was the chronic
replacement of microinverters and optimizers. 


What steps can be taken to create some balance in the rapid shutdown
requirements that are in the NEC? 


---

On 2020-04-29 07:27, Sky Sims wrote:

So far rapid shutdown has been a nightmare. It's added a lot of cost for no measurable benefit. 
Using always off devices like midnight solar and Tigo makes it impossible to test open circuit voltages. Which opens the door to tons of problems when commissioning systems.  
Also we've been trying out midnight Solar's product and have had an absurd failure rate. Which means lots of truck rolls and troubleshooting and system downtime. They send replacement product but they aren't paying for the lost weeks of productivity. 
We have Tigo product in hand and are deciding which project to try it on. But our big concern about using it is not only the inability to confirm open circuit voltage of the strings but also the way panels bypass if the device doesn't allow the panel to connect properly. Both of these features are a recipe for problems and potential troubleshooting nightmares. The warranty from Tigo doesn't cover our expense if the product fails. And that's really what our reservations about the product boil down to right now. If we're on a job with 50 units and one fails, the contractor or the homeowner will be the ones eating the expense of finding it and replacing it. There has to be a better option.  

Sky Sims 
Https://EcologicalSystems.biz 


On Apr 28, 2020, at 7:46 PM, Corey Shalanski  wrote:


Now that 690.12 of the _NEC_ 2017 has been in effect for several years, I am curious how designers and installers are meeting the associated requirements with string inverter-based systems (*not* considering microinverters or DC optimizers). I am generally a fan of the KISS principle, and as best I can determine the _Tigo_ TS4-F device is one of the simplest options currently available on the market. What are others finding? 

I'd love to hear about favored options for complying with rapid shutdown. Any success stories? or better yet, any early failures? 


--
Corey Shalanski 
Jah Light Solar 
Portland, Jamaica ___

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Re: [RE-wrenches] Rapid Shutdown Compliance

[August Goers]

Hi Corey - As we've grown, and as our fleet of installed systems has grown,
I've become increasingly interested in choosing an inverter solution that
shows per-module production data. I realize that you specifically asked not
to consider optimizers or microinverters, but I wonder if that will be a
losing battle. Module Level Power Electronics (MLPE) are getting more and
more reliable, and allow us to see what is actually happening with the
system for relatively easy troubleshooting down the road. Simply put, the
benefits outweigh the drawbacks, and they are only getting better.

That said, we're seeing some integrators going with the SMA / Tigo route
where you can choose the TS4-F rapid-shutdown-only variant of the Tigo unit
to reduce cost. You mentioned this. From the cost analysis that I've run,
I'm finding the SolarEdge is actually a bit cheaper than the SMA / Tigo
TS4-F route, especially when factoring in the long and flexible string
designs possible with SolarEdge. It's certainly possible that the KISS
route will pay off if one selects the Tigo route, but I think it's really
anyone's guess about which MLPE device will last the longest. Then there
are AC modules and Enphase type microinverters which are even simpler to
design and install with.

Anyway, it's a good question about whether there are any other viable
solutions to meet NEC 2017 rapid shutdown requirements out there. But I'm
afraid that the days of simple DC string based inverter systems are gone.

August
Luminalt




On Tue, Apr 28, 2020 at 4:46 PM Corey Shalanski  wrote:

> Now that 690.12 of the *NEC* 2017 has been in effect for several years, I
> am curious how designers and installers are meeting the associated
> requirements with string inverter-based systems (*not* considering
> microinverters or DC optimizers). I am generally a fan of the KISS
> principle, and as best I can determine the *Tigo* TS4-F device is one of
> the simplest options currently available on the market. What are others
> finding?
>
> I'd love to hear about favored options for complying with rapid shutdown.
> Any success stories? or better yet, any early failures?
>
> --
> Corey Shalanski
> Jah Light Solar
> Portland, Jamaica
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Re: [RE-wrenches] Rapid Shutdown Compliance

[Sky Sims]

So far rapid shutdown has been a nightmare. It’s added a lot of cost for no 
measurable benefit.
Using always off devices like midnight solar and Tigo makes it impossible to 
test open circuit voltages. Which opens the door to tons of problems when 
commissioning systems. 
Also we’ve been trying out midnight Solar’s product and have had an absurd 
failure rate. Which means lots of truck rolls and troubleshooting and system 
downtime. They send replacement product but they aren’t paying for the lost 
weeks of productivity.
We have Tigo product in hand and are deciding which project to try it on. But 
our big concern about using it is not only the inability to confirm open 
circuit voltage of the strings but also the way panels bypass if the device 
doesn’t allow the panel to connect properly. Both of these features are a 
recipe for problems and potential troubleshooting nightmares. The warranty from 
Tigo doesn’t cover our expense if the product fails. And that’s really what our 
reservations about the product boil down to right now. If we’re on a job with 
50 units and one fails, the contractor or the homeowner will be the ones eating 
the expense of finding it and replacing it. There has to be a better option. 

Sky Sims
Https://EcologicalSystems.biz

> On Apr 28, 2020, at 7:46 PM, Corey Shalanski  wrote:
> 
> 
> Now that 690.12 of the NEC 2017 has been in effect for several years, I am 
> curious how designers and installers are meeting the associated requirements 
> with string inverter-based systems (*not* considering microinverters or DC 
> optimizers). I am generally a fan of the KISS principle, and as best I can 
> determine the Tigo TS4-F device is one of the simplest options currently 
> available on the market. What are others finding?
> 
> I'd love to hear about favored options for complying with rapid shutdown. Any 
> success stories? or better yet, any early failures?
> 
> --
> Corey Shalanski
> Jah Light Solar
> Portland, Jamaica
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[RE-wrenches] Rapid Shutdown Compliance

[Corey Shalanski]

Now that 690.12 of the *NEC* 2017 has been in effect for several years, I
am curious how designers and installers are meeting the associated
requirements with string inverter-based systems (*not* considering
microinverters or DC optimizers). I am generally a fan of the KISS
principle, and as best I can determine the *Tigo* TS4-F device is one of
the simplest options currently available on the market. What are others
finding?

I'd love to hear about favored options for complying with rapid shutdown.
Any success stories? or better yet, any early failures?

--
Corey Shalanski
Jah Light Solar
Portland, Jamaica
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