Options for Grid-Tie Inverters w/limiting

ad8mustanggt

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I'm currently in the early stages of planninga small solarset-up as a proof of concept to see if designing/building a larger system (possibly including a powerwall) is worthwhile in my current location.

Right now I'm planning to have 4-5solar panels with a grid-tie inverter (probably around 1000w total). I'm in the USA in a location that makes it very difficult (expensive) to sell back to the grid so I'm stuck looking at GTI's that have limiters... Which brings me to my main question: Where are they? I've primarily seen 1 brand that's available and it's the SUN/ECO/Generic named blue box that everyone seems to be using. Model numbers similar to SUN-1000GTIL2-LCD.

Is SUN the only real player in the game right now for small systems? eBay seems to have some larger/more expensive models from "Tumo-Int" but I haven't seen much about these in use and they're well above what I'd like to spend on a POC.

Am I missing something? Not searching on the right terms? Or are the GTIL's just not as popular as it seems like they should be?
 

daromer

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Just a legal question that i feel i need to ask.
Is it even legal in your area to hook up a grid-tie unit to the grid? In most cases its not without permit. No matter if you sell or not.
GTIL is generally not allowed in many places at all but people tend to use them. In my area they are for sure not allowed.
 

ad8mustanggt

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It's a good question, and like anything else technology related (specifically talking about the limiting part of a GTIL) the codes and regulations are always a bit behind the times.

Is someone going to come throw me in jail for using a GTIL? No. Could I potentially get fined by the power company if I'm back-feeding into the grind without paying them to let me do it? Could local code-enforcement come tell me I need to remove the solar panels because they were installed on my roof without a permit? Sure, those potentials are always there.

On a broader discussion I think we can all agree that most DIY types have done work "Illegally" by not getting a permit. In my experience most urban/suburban places in the USA don't let you do much of anything without someone else saying it's ok. Electrical, plumbing, new patio in the back yard? Yep - Get a permit. Is it strictly enforced? Not usually unless it's highly visible or someone else complains. I can't even build a small shed on my property without a zoning permit...

But - for sake of this project and specifically talking about the inverter, It's a grey area for me. There are no local codes (that I could find) strictly prohibiting the use of GTIL's. GTI's are't allowed by the power company without going through their application, design and permitting process but again, nothing specifically about GTIL's. The limiting part is why it's a grey area in my mind, nothing I'm doing will ever leave my house. Technically do GTIL's fall under the same regulations as GTI's? Probably, but there's an argument to be made that they don't. Obviously this is an entirely different discussion if we were talking about a normal GTI for which there's no question are illegal w/out the power-company's sign-off.

I'm planning to follow all the normal/official rules and codes for installing solar panels as well as some additional safety measures that have been talked about here to make sure everything is as safe as can be. But if a panel falls off the roof and lands on the neighbor's dog, I fully understand I'll be liable for that.


Having said all that - My official public stance is YES... Everyone should follow, to the letter, all local laws, codes and regulations they're governed by and have a licensed, trained and insured professional do any and all work. Don't buy or use anything not UL listed and wear a condom at all times.
 

Doin it

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Not many grid tie options with limiter, some limit in settings, some use limiter clamps..Ive heard that the inverters that u limit in the settings are not as good at limiting. The gtil2 Tfl can have higher voltage inputs (many panels in series). The blue gtils run on lower voltage inputs and can run off of batteries due to this...u just gotta figure out what u want
 

Generic

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Anything connected to home wiring needs to be UL-listed / tested by a NRTL like ETL, etc. Specifically it's UL1741 for all home inverters, whether grid-tied for net metering, grid-tied and limited, or even off-grid believe it or not. ETL certification is why a 8kW Aims Off-Grid inverter costs $400 more than the 10kW Aims Off-Grid inverter despite having lower output. UL1547 comes into play if you are tied into the grid whether you are exporting or not. If you expect to get a permit, your AHJ will require an NRTL certificate.

And you are correct about selective-enforcement. Almost a year ago, I was forced to take down my ground-mount solar, and to-date, no other code violations by my neighbors have been cited by code-enforcement even though they are pretty obvious, like non-permitted sheds on easements, unpermitted home additions, and irrigation systems without a backflow preventer, etc.

TLDR: GTIL's fall under GTIs because they are tied to the grid. UL1547, UL1741, and NEC Article 690.
 

daromer

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Generally i wold say the legal part is one of the smaller parts for grid tie but the concern i generally have is using grid-tie systems perhaps not approved, informed or even faulty units on the grid where potentially a line-worker come and do work.
If they dont know about the install and it is faulty or something happen they could potentially get hurt.

So now lets leave that because no one want to hear it :p

I would say they are not as popular because they are DIY and generally not legal. Thats the reason no one sells them where I live as example.

Many sellers in Sweden actually had to remove huge amount of inverters some time ago due to regulations and suddenly the market was very low and the ones left was expensive.
 

Generic

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Aside from testing certificates, the big difference I've seen between certified and non-certified Grid Tie Inverters is the delay in time when reconnecting to the grid. The non-certified ones will start exporting power the second they detect grid voltage, while the certified ones have a 5 minute wait period before exporting after a grid-down scenario. All grid tie inverters have anti-islanding by their very nature - they operate by sensing grid voltage and inverting DC into AC at a slightly higher voltage than the grid voltage they sense. If the grid goes down, they can't sense a voltage in their range of operation and cease producing power. The real danger to linemen is from off-grid equipment - Generators and inverters that create voltage independent of the grid. When connected to the grid in a grid-down scenario, they create voltage on the demand side of a power line that shouldn't be there.
 

ad8mustanggt

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Generic said:
Anything connected to home wiring needs to be UL-listed / tested by a NRTL like ETL, etc.

Can you cite your source for the UL/ETL/etc requirement for any device plugged into house power? As far as I've been able to tell (happy to be proven wrong here) there's no hardrequirement for a UL stamp or any formal testing/certificate in the USA. It's highly recommended and generally thethe de facto safety standard but there's nothing stating that I'm only allowed to use UL listed devices. Don't get me wrong, I think UL testing is necessary for the massesand am glad it's the accepted standard around safety but in the end it's up to me as the end user to know what I'm using and to do it safely.

I do agree that a certification of some kind will berequired to get a permit and approval from the power company, but it's not a blanket requirement across anything that gets plugged into home wiring.

I completelyget the concern with back-feeding the grid in the event of a power outage. The last thing I would want is for someone to get hurt because a GTI didn't properly anti-island itself which is why I'm also planning an under/over voltage relay as a secondary shut-off in the event grid power is lost as well as a timer to make sure power is stable before starting back up... Butthose devices probably won't be UL listed either ... :rolleyes:


This is a good discussion though I'm still surprised GTIL's are so much less prevalent than a cheap/simple GTI considering all the issues that come with back-feeding the grid.
 

RikH

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ad8mustanggt said:
This is a good discussion though I'm still surprised GTIL's are so much less prevalent than a cheap/simple GTI considering all the issues that come with back-feeding the grid.

Maybe you should have a look at the south africanpowerforum The Africans down there are mostly not allowed to feed back into the grid so they use a lot of GTIL but also power diversion solutions that can help you out as well. And yeah, where a condom in Africa as well! :)
 

Doin it

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Lmao...for me tho just dont backfeed and use gtil, regardless of any certification. Many of the inverters are certified in other countries. If someones house burns down its most likely due to improper installation. If e-company knocks on my door I dont have to let them in.. If they want to shut my power off then Ill go full offgrid then they get no money from me..
 

brandonoh777

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Generic said:
Anything connected to home wiring needs to be UL-listed / tested by a NRTL like ETL, etc. Specifically it's UL1741 for all home inverters, whether grid-tied for net metering, grid-tied and limited, or even off-grid believe it or not. ETL certification is why a 8kW Aims Off-Grid inverter costs $400 more than the 10kW Aims Off-Grid inverter despite having lower output. UL1547 comes into play if you are tied into the grid whether you are exporting or not. If you expect to get a permit, your AHJ will require an NRTL certificate.

And you are correct about selective-enforcement. Almost a year ago, I was forced to take down my ground-mount solar, and to-date, no other code violations by my neighbors have been cited by code-enforcement even though they are pretty obvious, like non-permitted sheds on easements, unpermitted home additions, and irrigation systems without a backflow preventer, etc.

TLDR: GTIL's fall under GTIs because they are tied to the grid. UL1547, UL1741, and NEC Article 690.

Yes this is also why a spark plug for regular air breathing gasoline burning horizontally-opposed aircraft engine cost around 30 some dollars when one for your car made by the same Champion company cost a few dollars... while a quart of oil for that same airplane engine will cost you about $15 we're one for the virtually the same engine in your car will cost you what $5... I could go on and on about HOAs and other things but we all know too much of anything is bad lol I'm not personally saying regulation was ever good in the first place but I think we can all agree too much of it is bad
 

Wolf

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brandonoh777 said:
Generic said:
TLDR: GTIL's fall under GTIs because they are tied to the grid. UL1547, UL1741, and NEC Article 690.

Yes this is also why a spark plug for regular air breathing............................................but I think we can all agree too much of it is bad

So I wonder how they get away with it.
https://legionsolar.com
https://drive.google.com/file/d/1HvV7SSmRq8MGRwgn_oCkrZslVw4tQYoP/view
According to them anything after the meter is yours and yours alone and cannot be regulated by the power company or anyone else for that matter. :huh:

Wolf
 

Cheap 4-life

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image_ouniox.jpg

Thats how I look at it. UL certifications etc usually make things cost more. As long as Im not pushing power past my meter from an inverter then it shouldnt, dare I say doesnt matter.
 

OffGridInTheCity

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Let me share my mindset. Not to bejudgmental but rather the thinking that lead me toa UL/ETL mindset over time :)

I went UL/ETL 100% (equipment, boxes, circuit breakers, etc) and NEC standards (boxes, conduit for DC, grounding, ...)because....
*according to my electrical engineer friend.... UL/ETLensures a level of components inside the equipment that are likely to be 'more robust' / 'more in line with specs' than if its not UL/ETL inspected/certified. Its even possible the equipment will even last longer and you'll recover the extra $- who knows.
* I've been told (but have no experience) that my home owner's insurance will give me a hard time if the equipment that caught fire is UL/ETL.
* My local jurisdictions - which do have authority if I'm outed by a neighbor or house inspection if I sell - require UL/ETL and code compliance.
* My family lives in the house.
* Consideration for neighbors - don't want to risk a housefire that might catchtheir house on fire.
and because.....

In the beginning, learning about Solar, trying things out - I totally get it! Its FUN and you're learning and your on top of operations every 30minutes! Now,after 3 yearsI'm transitioning to ongoing operational mode instead of experiment mode - and expect this system to run the rest of my life. I even go 48hrs now without close monitoringbecause I'm busy with other stuff. So now all is UL/ETL, up to code,with BMS and shunt-trips :)
 

daromer

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Not following here = No insurance if shit hit the fan and also for the grid part = they can shut me off and send me penalty that is more than the cost of following standards.
Even worse.. I can hurt someone working on the systems or my family and i would say thats the most important thing.
Though standards doesnt make up for a poor install but atleast the gear used and how its used is one key factor.

And Yes i have done alot not following standards and still do but i choose the areas more wisely the older i get :)
 

OffGridInTheCity

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>Not following here = No insurance if shit hit the fan
Yea - I mistyped about insurance and corrected the post above. I was trying to say that my homeowner's insurance may be reluctant to cover a fire if the equipment that started a fire was not UL/ETL.

>... and still do but i choose the areas more wisely the older i get
Yes - for example I have fire protection around the 18650 battery bank but it wouldn't stop amajor/cascade event. Maybe a shipping container in the yard some day, but not currently:)

>even worse.. I can hurt someone working on the systems
Yes sir - that's why I have + and - at opposite ends of my battery packs (much harder to accidentally short),religiously use or tape wires red +/black - (helps avoidconnecting obvious red + wire to a black - wire accidentally causing massive shorts), have isolation circuit breakers between parts of the systems to work safely, avoid home grown grid-tie,etc etc :)

And I confess - I am an old man... it does color your thinking compared to being 25!
 

Cheap 4-life

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I agree. For me tho Ill do research and make sure the equipment is made safely and up to or close enough to UL standards so I can save a few bucks.
Sometimes equipment etc. doesnt get their proper certification in a certain country simply because it would have made the product cost more to purchase. The equipment could be made just as good. One day I might make sure everything is UL certified. I got into solar to save money. Its become a hobby that I enjoy that also saves me money. There wasnt any UL certified inverters that are grid tie and can stop power from entering the grid. If there was I probably would have purchased them instead and had a slightly longer ROI. If I wanted a net meter to feed into the grid (past the meter) then there was no ROI - saving money for me. They have their own installers install every bolt-panel etc. yearly-monthly fees, maintenance by who they choose paid by me, red tape etc.
Another option for me was to use offgrid inverters transfer switches etc. This option done right (without extension chords etc) made it so would break even in my lifetime. So it was either that or get a couple GTIL2s with an ROI of 6 years (has turned into roughly 8 years) then free electric. Also since the GTIL2 can operate using a common battery voltage, I connected an offgrid inverter to that battery for emergencies. So an ROI of 8 years and can still use my system to power essential loads when the power is out was most appealing.


I could be wrong but insurance companies still pay the home owner for fire damage when faulty wiring was the cause. Wouldnt a fire from a non UL certified device be the same?
 

daromer

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In Europe they dont. They will look between the fingers if its done by you even though you arent certified as long as it follows standards...

But if they find out the the cause, for instance fire, was due to tampering or installing home made batteries you wont get shit. You will most likely even be guilty for the time the spent investigating.

With that said the funny thing is that you are allowed to set fire on your house in Sweden without any blame but you cant do it to get the money... :)

So if my garage burns down and they see that the cause is due to the battery that is diy i will lose 50 000EUR... But if it was due to the inverter or wiring then they will pay out. (They are properly approved and even electrician signed it off)

Its like car insurances in Sweden. If you have tampered with the software in the car you wont get anything on warranty on the engine if it fails. If you go to a track and you race it you dont get anything...
IF you crash the car on purpose to get money you dont get any but if you have full ensurance and the crash was due to failing rules you will get a new car but you can end up with loosing your drivers license... :p

Alot of OT. But this was Sweden and it differs between insurance companies and countries.


Forget to answer your initial question: Faulty wiring depends. Mistakes yes.. But not skipping ul or rules by doing it your self even though you know its wrong and everyone in Sweden knows you arent allowed to do it. It is written basically everywhere :p
 

OffGridInTheCity

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>Wouldnt a fire from a non UL certified device be the same?
If its UL/ETL - the investigation (of a fire) will likely stop there - e.g. this (UL) equipment started the fire.. finished. If its not UL/ETL equipment - then they know for sure it was not permitted as no electrician / city inspector (in Oregon USA)would install/approve non-UL/ETL and that might start a deeper investigation for permits etc. Who knows... you can betinsurance companies don't like to pay no matter what!

But we all agree - the best bet is to just do safe/good work and avoid all this in the first place and I notice that I've not read on this forumof any serious fires etc..- which is encouraging!:)
 

not2bme

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Just FYI over this weekend I decided to fire up my Conext XW6848 for the first time since I purchased it well over a year ago. It is a mess of a product. For one it doesn't do AC grid coupling as it states on the web. Secondly, the Schneider menu system is like a damn puzzle with no sense to their labeling. It's almost as if the engineers created this product without any guidance. Would not recommend this for AC grid coupling for sure! Wouldn't even recommend this as an off-grid inverter as well. For one it doesn't have a simple SBU mode like the PIP. It requires you to be connected to the grid, causing excess consumption that I can't figure out.

But I did learn about another Outback product called Skybox that is slightly different in their Radian series for better grid zero application. Seems like a possible good solution for a gridzero ac coupling.

Here's someone that set it up.
https://diysolarforum.com/threads/ac-coupling-my-outback-skybox-to-a-solaredge-inverter.10901/
 
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