got fined 1k for an off-grid, 500 dollar, 9 panel system i lay on the roof

[再生可能 エネルギー]

The disconnect has to be automatic, i.e., if the main cut off switch is engaged, the panel attached shutdown module activates. Since voltage is the concern, I would assume the unit actually shorts the panel internally to eliminate voltage.

Some Tigo optimizers have this function built-in ($50/panel), and they make standalone cut-offs ($35/panel) as well.

Microinverters take care of it since they're already on each panel.


Now if the
No. The PV panel must not present a shock hazard to someone on the roof.

Is there a specific NEC rule defining how the automatic solar panels disconnect should occur and be triggered?

- It seems that, from the above comment, if the main powers switch of a building is turned off,
this will de-energize the whole solar shutdown system.

But in case of a fire, should the main power switch been shutdown automatically, by a smoke detector for example,
or should a firefighter's first operation would be to turn off the main power? If the main power cannot be accessed
because of its location, on the back of a building or inside a garage, nobody would then be able then to turn off the power.

- Should there be a way then to de-energize the whole solar shutdown system using a special switch easy to access,
such as from the front of a building?

Now in case of an outage, there will be no power to the building from the Grid,
and as a result, the whole solar shutdown system will be de-energized.
However would there be a way to use solar energy in this case, especially if the outage is not temporary
and occurred because of a major disaster, such as an earthquake or a tornado?

- So would there be a contingency mechanism able to keep the whole solar shutdown system to stay energized in case of an outage?

In the case of an Of-Grid installation, since there is no typical outside accessible meters and main switch:
- how a firefighter would know how to turn off the main power and shutdown the solar system?

In case of an inspection of a building (connected or not to the Grid), beside turning off the main power,
which can be not very practical when the building is occupied,
- is there a specific easy way to test the whole solar shutdown system?

 

[Hedges]

I think visible blade disconnect and RSD control are supposed to be near electric service entrance. Or somewhere, for an off-grid system.
Shutdown would be manually operated by emergency personnel.

My plan is the single switch accomplishes both. If just GT PV, removing AC triggers RSD. If a battery backup system, grid down transfers to battery, but if switch is thrown then an extra contact shuts down the system.

I would have an override switch inside I could use to turn power back on, if someone was trying to cut my power while I was home.

You ought to have a transfer switch or interlocked breaker to bypass inverter in case of failure. Using that, you could keep the house powered while demonstrating RSD and inverter shutdown. Of course there would be a period of power off while switching between the systems.

 

[Scoob-SanDiego]

Is there a specific NEC rule defining how the automatic disconnect should occur and be triggered?

- It seems that, from the above comment, if the main powers switch of a building is turned off,
this will de-energize the whole solar shutdown system.

But in case of a fire, should the main power switch been shutdown automatically, by a smoke detector for example,
or should a firefighter's first operation would be to turn off the main power? If the main power cannot be accessed
because of its location, on the back of a building or inside a garage, nobody would then be able then to turn off the power.

- Should there be a way then to de-energize the whole solar shutdown system using a special switch easy to access,
such as from the front of a building?

Now in case of an outage, there will be no power to the building from the Grid,
and as a result, the whole solar shutdown system will be de-energized.
However would there be a way to use solar energy in this case, especially if the outage is not temporary
and occurred because of a major disaster, such as an earthquake or a tornado?

- So would there be a contingency mechanism able to keep the whole solar shutdown system to stay energized in case of an outage?

In the case of an Of-Grid installation, since there is no typical outside accessible meters and main switch:
- how a firefighter would know how to turn off the main power and shutdown the solar system?

In case of an inspection of a building (connected or not to the Grid), beside turning off the main power,
which can be not very practical when the building is occupied,
- is there a specific easy way to test the whole solar shutdown system?

I did a bit of reading on the subject and it's thick with (protective if burdensome) bureaucracy.
Here is my series of links and notes. This is just a copy of my personal summary notes so it might not be as polished as could be.

But to answer your questions, off the top of my head from what I recall reading/viewing:

They expect that when the main power to the building goes down, BOTH the solar array AND the AC output to your inverter goes down (i.e. < 30V on the PV wires outside the array and 0V AC coming out of your inverter. I *THINK* you also need a separate switch to trigger this as well (or at least, to perform rapid shutdown on the PV array). Some all-in-one inverter systems (Sol ArK, EG4 (not the small model)), have built-in RSS where you can connect it to something like the Tigo wireless controller which will shut down the solar part of the equation.

But like you pointed out, it doesn't really make sense if the power goes out to have the PV system self-shut down.... bureaucracy for you!
BUT, you CAN setup those systems to pass inspection and I'm sure you can change the behavior of the inverter in response to grid power out from the configuration console later.

Also please note that this is just the RSS part. I have included some notes at the end of this post regarding the ARC Fault Protection requirement under the NEC (you have more than 80V on the PV lines... they demand that you be protected).

---

My RSS NOTES:

NEC 2017 / 2020 require Rapid Shutdown System (RSS)

• Overview:
• • 30sec after RSS initiation, power withing the array must be < 80V and outside the array < 30V
• Comment:
  • Given that DC doesn't spark until about 80V, then a 60V PV string setup like mine does not warrant an RSS (even if code would demand it... safety does not)
• Details:
  • https://www.purepower.com/blog/2017-nec-690.12-rapid-shutdown-important-changes
  • https://www.mayfield.energy/technical-articles/nec-2020-rapid-shutdown-requirements/

• NEC code (look at section 690, PV stuff... about 16 pages):
• • https://www.nfpa.org/codes-and-standards/7/0/70
  • LOGIN (free membership)
  • Select edition and click Select Edition
    click "Free Access" button.

• Overview of the Tigo System:
  • Tigo has RSS modules and/or RSS + monitoring/optimizing modules
  • All devices connect panels in series and by default DON'T let any voltage/current through UNLESS the transmitter signal is present and ON.
  • There is an external transformer and transmitter which sends a singal OVER the solar cable coming back from the panels on the roof.
  • If you use the monitoring / optimizing modules, then you need an extra box.. one for every 300 modules? position within 10Meters etc... not a big deal

Accomplished by using one of the folloing line of Tigo products:

RSS AND monitoring/optimization models:

• https://www.tigoenergy.com/product/ts4-a-o
• $44 - https://signaturesolar.com/tigo-ts4...own-15a-700w-1500vul-1000viec-mc4-1-2m-cable/
• This takes care of bypassing any module that is in the shade... keeps your string productive even with partial shading.
• App and web based monitoring. Very cool and clever.
• Has RSS
• Requires extra gear (takes care of monitoring AND RSS)
  • You need ONE Tigo Access Point (TAP) per roof (240 modules).
    • https://www.tigoenergy.com/product/tigo-access-point
    • The TAP is mounted behind a panel on the roof
    • The TAP communicates with the tigo modules through a proprietary mesh network.
    • It has to be within 10m of ONE TS4, then the TS4 connect from one to another using that mesh.
  • You need one Cloud Connect Advanced (CCA)
    • https://www.tigoenergy.com/product/cloud-connect-advanced
    • The CCA can connect to up to 7 TAP
    • The CCA is at ground level (close to power and wifi) and is connected to the TAP(s) using a RS-485 cable.
  • The kit with both:
    • $300. https://signaturesolar.com/tigo-tap-din-rail-ps-outdoor-enclosure-kit/
    • Installing the CCA / TAP.
    • Manual RSS switch connection:
      • https://support.tigoenergy.com/hc/e...g-a-Manual-Latching-Push-Button-Safety-Switch

Monitoring and RSS: Mostly for LARGE installations (to monitor)\

• https://www.tigoenergy.com/product/ts4-a-s
• App and Web based monitoring (per panel)
• Needs CCA/TAP (above)

Monitoring only: (again, only for solar farms)

• https://www.tigoenergy.com/product/ts4-a-m
• Needs CCA/TAP (above)

or JUST RSS: (that or the first option w monitoring + optimization seem more suited for home solar)

• Single module unit:
  • https://www.tigoenergy.com/product/ts4-a-f
  • $30 - https://signaturesolar.com/tigo-ts4-a-f-rapid-shutdown-15a-700w-1500vul-1000viec-mc4-1-2m-cable/
• Dual module unit:
  • https://www.tigoenergy.com/product/ts4-a-2f
  • $46 - https://signaturesolar.com/tigo-15a-1000w-1500vul-1000viec-2-2m-cable-mc4-ts4-a-2f/
• Extra gear needed:
  • RSS Transmitter.
    • https://www.tigoenergy.com/product/rss-transmitter
    • Works up to 300 meters (solar cable from array to inverter)
    • Transmitter + transformer kit $145
      • https://signaturesolar.com/tigo-sin...vac-ps-outdoor-enclosure-rss-transmitter-kit/
  • RSS transmitter installation:
    • https://www.youtube.com/watch?v=zleds4Q00W8
    • https://www.youtube.com/watch?v=okfot1kvhlw
  • Manual emergency shutdown switch:
    • For the RSS only solution, your emergency switch will simply be a shutdown of the AC power coming into the 12v Tigo transformer.
    • If your inverter has an emergency shutdown (of ougoing AC) then connect your transmitter to your inverter's outgoing AC.
    • Note that if your batteries get fully depleted and you are off-grid, then your system will NOT reboot from solar. You NEED AC power (or at least 12V power to the transmitter for the PV power to flow in

• All the Tigo gear at Signature Solar:
  
  • https://signaturesolar.com/shop-all/system-components/rapid-shutdown-equipment/

If you have an RSS capable inverter, it will have connectors to connect to the RSS transmitter.
You can (should!?) wire an additional external switch to trigger the PV shutdown.

 

[Scoob-SanDiego]

.....

Also please note that this is just the RSS part. I have included some notes at the end of this post regarding the ARC Fault Protection requirement under the NEC (you have more than 80V on the PV lines... they demand that you be protected).

---

This is the last part of my post with my notes regarding the ARC Fault Protection

My ARC Fault Protection NOTES:

NEC 2017 / 2020 requires ARC fault protection with PV systems operating at more than 80V

NOTE on Arc Fault Circuit Interruption (AFCI) NEC requirements.
Any PV operating at > 80V is now required to have AFCI compliance ... i.e. be able to identify a serial arc fault and shut down the string.
AFCI breakers work by detecting high frequency noise caused by arcs. High frequency switching noise from inverters will not make them happy.

Some info on Arc Fault:

• https://www.acsolarwarehouse.com/news/solar-fires-dc-arc-faults-on-solar-systems/
• https://www.sma-america.com/partners/knowledge-base/pv-arc-fault-circuit-interrupter
• https://solarstone.com/blog/how-to-prevent-solar-rooftop-fires-with-an-arc-fault-circuit-interrupter
• https://www.wattscore.com/post/what-is-arc-fault-in-solar-systems-and-how-to-deal-with-it

• Tigo systems are compatible with certain inverters with built-in AFCI compliance (Sol Ark etc...)
  • https://support.tigoenergy.com/hc/en-us/articles/203508327-AFCI-Compliance

More info from Diysolarforum:

• https://diysolarforum.com/resources/solar-array-arc-fault-protection-summary.145/

Comment / Conclusions:

• There are no stand alone devices available (early 2024) that provide ARC fault protection.
• The only way to have it right now is through some of the top end ($$$) inverters (Sol ArK etc...)
• It means that. you CANNOT build a system that will be code compliant with the more economical inverters

Again, these are my personal notes and may not be 100% accurate!

 

[再生可能 エネルギー]

Thank you @Hedges and @cmarcotte for your reply and valuable content.

Now adding a rapid shutdown device (RSD) to my instalation starts to be a little more hairy.

Turning off and isolating the PVs is quite straight forward, but I also use a transfer switch​

between the Grid and my battery system.​

​

This looks simple on paper, but I already added some logic to automatically have the Grid mode​

to use the battery in case of outage, and reciprocally having the Of-Grid (default) mode to use​

the Grid when the battery is discharged.​

​

It seems that, on top of my transfer switch system, I needs to implement an emergency switching mechanism​

shutting down everything automatically when the main power get turned off. And in the background,​

having a maintenace mode for testing the solar shutdown or to be able to use the Of-Grid in case of an outage.​

I started reviewing the Tigo documents and subscribed to the Tigo Academy and I will try to build a prototype version.

About the Arcing compliance, this is a tricking point. I have some DC solar lightning arrester on each PV string,
but I doubt that would be sufficent to be Arc Fault Circuit Interruption (AFCI) compliant?

 

[Hedges]

AFCI is a circuit that looks at noise on the line, ignoring the switch mode power supply fundamental and harmonic frequencies, detecting much lower power level "hash" that an arc creates. Then it open-circuits or otherwise shuts down current draw. I think it provide digital signal processing, so sophisticated electronics and software.

There are few if any stand-alone AFCI devices.
Midnight Classic SCC provide it.
Most newer inverters for grid-tie in the US provide it.

Old equipment installed before AFCI requirement would be grandfathered.
Newer equipment installed in a permitted system would have it.
Problem would be old equipment that someone installed and wants to bring up to code, or bought and now isn't allowed to install.

 

[road glide]

What kind of strength training does an 79 year old have to have to build and fit 5S5P arrays together dig the trenches and fit in the conduit and with the help of a 76 year old wife pull all the cables into the conduit. So 25 panels each weighing about 40lbs a piece over a couple of days is no major sweat.

Boom!

 

[再生可能 エネルギー]

AFCI is a circuit that looks at noise on the line, ignoring the switch mode power supply fundamental and harmonic frequencies, detecting much lower power level "hash" that an arc creates. Then it open-circuits or otherwise shuts down current draw. I think it provide digital signal processing, so sophisticated electronics and software.

There are few if any stand-alone AFCI devices.
Midnight Classic SCC provide it.
Most newer inverters for grid-tie in the US provide it.

Old equipment installed before AFCI requirement would be grandfathered.
Newer equipment installed in a permitted system would have it.
Problem would be old equipment that someone installed and wants to bring up to code, or bought and now isn't allowed to install.

Well, making NEC compliant a DIY Of-Grid solar system seems more and more convoluted and puzzeling...
I try to be more precise as possible before submitting any permit, is there a list of SCC who are AFCI and RSD compliant?
In particular when using separate SCC and DC/AC Inverters, like Victron, instead of AIO systems.

So in case of an AFCI alert, what would be the process for restarting the solar system.
Does each panel needs to be tested to check if there is any arcing risk, and how this can be tested and who can do it.
What about if this was a false positive, can the system restart automatically or manually.

 

[Scoob-SanDiego]

Well, making NEC compliant a DIY Of-Grid solar system seems more and more convoluted and puzzeling...
I try to be more precise as possible before submitting any permit, is there a list of SCC who are AFCI and RSD compliant?
In particular when using separate SCC and DC/AC Inverters, like Victron, instead of AIO systems.

So in case of an AFCI alert, what would be the process for restarting the solar system.
Does each panel needs to be tested to check if there is any arcing risk, and how this can be tested and who can do it.
What about if this was a false positive, can the system restart automatically or manually.

Honestly, I don't know if a DIY *CAN* be compliant in certain states. I live in CA and it's the land of government oversight :-(. They don't make it easy or clear WHAT the requirements are. Even the permitting requires a solar contractor to do the actual job (or at least to sing on it). I have the impression (not based on any sort of statistical analysis) that it's really only geared for Solar contractors to use a handful of approved set of inverter.... That the basic plans were approved once and they keep repeating the same plan with very minor changes to minimize issues with the bureaucracy etc.. In other words, it does not look possible or at least very unlikely that you CAN do a legit, up to code and inspected/approved DIY solar system with string inverter and DIY gear.... you have to move to more expensive equipment (Sol Ark) or use micro inverter, and get a solar contractor or electrician to do the install. All of which significantly increases the cost of your solar project :-(

PS: I would LOVE to be wrong and have someone lay out a clean 10 steps process or a DYI (in CA) to get permit and approval.

 

[Hedges]

Midnight Classic, Hawke's Bay, and Barcelona are SCC with AFCI and GFCI (possibly using optional accessories.)

AFCI might trip due to interference or motors. Or, could be an arc, so instructions say to not reset remotely.
Tracking down an arc that hasn't burned anything is likely difficult.
Ground fault, if it remains, would be easier.

 

[Bop]

Jeez- glad i don't live in the 'land of the fee'- here in Aussieland, there are a few simple rules for offgrids- adequate mounts for the wind classification (maps and requirements readily available eg roof mount requirements pdf 12 pages) and DIY is allowed for the panels string wiring up to 600vdc as long as it is 'plug and play' ie MC4 connectors meet this and DIY is fine with no 'permits' or anything required for an offgrid system at all- even in the middle of town its no big deal- as long as it remains independent of the grid mains, you are good to go... (you can even use it as an 'emergency generator' as long as you have a licenced electrician fit an approved 'changeover switch' and you plug into that....) and batteries are to be outside a 'habitable structure' ie not inside a house, has to be a separate building/shed made of a fireproof material (thats all battery types- L/A, lithium, NiMH, whatever)- although it is a 'honour system'- there's no inspections of offgrid systems at all...
Hell when council did the final inspection of my shed after finishing it- he walked past my 'temporary' panels and didn't even look at them in the inspection, apart to say 'nice little system, how much it cost ya???'
(and thats on timber frames held down by water filled IBCs with rachet straps!!! lol)


Gridties are more regulated- basically- don't touch it- thats the realm of licenced electricians only...

 

[Kenny_]

Yes . Land of the Fee!!!

 

[y0bailey]

Jeez- glad i don't live in the 'land of the fee'- here in Aussieland, there are a few simple rules for offgrids- adequate mounts for the wind classification (maps and requirements readily available eg roof mount requirements pdf 12 pages) and DIY is allowed for the panels string wiring up to 600vdc as long as it is 'plug and play' ie MC4 connectors meet this and DIY is fine with no 'permits' or anything required for an offgrid system at all- even in the middle of town its no big deal- as long as it remains independent of the grid mains, you are good to go... (you can even use it as an 'emergency generator' as long as you have a licenced electrician fit an approved 'changeover switch' and you plug into that....) and batteries are to be outside a 'habitable structure' ie not inside a house, has to be a separate building/shed made of a fireproof material (thats all battery types- L/A, lithium, NiMH, whatever)- although it is a 'honour system'- there's no inspections of offgrid systems at all...
Hell when council did the final inspection of my shed after finishing it- he walked past my 'temporary' panels and didn't even look at them in the inspection, apart to say 'nice little system, how much it cost ya???'
(and thats on timber frames held down by water filled IBCs with rachet straps!!! lol)

View attachment 196282
Gridties are more regulated- basically- don't touch it- thats the realm of licenced electricians only...

I haven't read the whole thread, but the OP didn't even meet your "lax" requirements.

He didn't have adequate mounts for the wind...he had fucking 40 pound projectiles laying on his roof.


I'm not exactly permitted, but I kept as close to code as possible. Especially for my mounts/panels.

If he sent a projectile into my car and I had to deal with it, I would be pissed. My "freedom" just got impeded upon because I have to deal with my insurance company. If he gets away with not paying for a potential mishap, my rates go up.


This was stupid. He got caught because of it. He could have caused issues for his neighbors. Or the insurance company that will pass their losses to you or I (to be fair, fuck the insurance company...but we eat their losses).

 

[mototrackside]

I wouldnt place them on the roof. Dont you have pergolas in the back? I would put these somewhere else other than the roof especially if these are not anchored. I am socal so we get a lot of misc enforcers for the dumbest thing, which end up being non-violations. I'm hillside so I can hide a lot of my personal setups. The haters always call for everything. I once was installing a tall privacy fence away from the property lines. An enforcer got called to look at it, and said I could go higher I wanted to because I was not on the property lines. The retarded that called had nothing. The things i have pulled permits are for serious setups like electrical panel. I upgraded a 200 amp panel.

 

[再生可能 エネルギー]

Midnight Classic, Hawke's Bay, and Barcelona are SCC with AFCI and GFCI (possibly using optional accessories.)

AFCI might trip due to interference or motors. Or, could be an arc, so instructions say to not reset remotely.
Tracking down an arc that hasn't burned anything is likely difficult.
Ground fault, if it remains, would be easier.

So in case of an AFCI alert, what would be the process for restarting the solar system?
- Does each panel needs to be tested to check if there is any arcing risk, and how this can be tested and who can do it.
- What about if this was a false positive, can the system restart automatically or manually.

 

[Hedges]

I haven't dealt with it yet. Appears to be manual reset.
Checking seems to be visual and pull testing.

For Sunny Boy, you knock on the front and yell "Anybody Home?" or something like that.

Tech Talk: Five tips for AFCI troubleshooting - Sunny. SMA Corporate Blog

It’s something installers hate to hear and hate to troubleshoot: the dreaded DC-side arc fault. Rarely in solar can such...

www.sma-sunny.com

Resetting the Operation Inhibition after Detection of an Arc Fault

manuals.sma.de

Although it would be possible to do it by resetting parameter remotely, for safety it is recommended not to do that except when present to observe.

Midnight, have to RTFM. I've only gone through SMA manuals in detail.

 

[teal95]

AFCI can also be triggered by optimizers (SolArk + TIGO seems to be a problem). Until I've passed inspection (this week, I hope) I just keep using the reset button.

 

[Ampster]

Even the permitting requires a solar contractor to do the actual job

I disagree. I have done two solar installations in California as an owner builder. These were in two different jurisdictions in the past fourteen years. I just received permit approval for a SolArk inverter and an Energy Storage System as an owner builder in a Northern California County. I am sure there is a City somewhere in California where your statement is true but that has not been my experience.

 

[Scoob-SanDiego]

I disagree. I have done two solar installations in California as an owner builder. These were in two different jurisdictions in the past fourteen years. I just received permit approval for a SolArk inverter and an Energy Storage System as an owner builder in a Northern California County. I am sure there is a City somewhere in California where your statement is true but that has not been my experience.

I'm delighted to hear it!
I would *assume* the more remote/rural, the higher the chances that bureaucracy might be a tad lighter.
Unfortunately it doesn't appear to be that easy in San Diego County :-(