Poor mans grid-tied system.. The plans.. Fire hazard? Or will it actually work?

pivot.enabled

Re: Poor mans grid-tied system.. The plans.. Fire hazard? Or will it actually work?

Cariboocoot wrote: »

There is quite a difference in interacting with the utility by using their power and interacting with it by sending them power.

Likewise there is a difference between installing an outlet that meets NEC specs to run a load and installing any type of power input connection.

If you do not understand the difference you should not be attempting to do it nor be advising others to do so.

Also there is another simple option.....

Install a transfer panel and weatherproof inlet plug as can be legally utilized with a generator... All permitted, all legal and *relatively* low cost.

Again this provides the OP with cheap start up cost and expandability as his budget allows.

BB.

Re: Poor mans grid-tied system.. The plans.. Fire hazard? Or will it actually work?

There are lots of safety issues... Roof has to be strong enough to hold the array and not leak (wind and snow loads).

In general, the metal structures and solar panel frames need to be "permanently" attached to a green wire/safety ground (Don't want the array to become "hot" if the green wire ground is disconnected/unplugged). And in lightning prone areas, it is usually much safer if the solar panel frames/mounting rails ground wire is ran on the outside wall of the building (with few or wide radius curves), to a ground rod/grounding system at/near the base of the wall.

A true "plug and play" system cannot meet those requirements.

Another issue that may be confusing the discussion--There are plug-in systems that work on 120 VAC (or 230 VAC) that are just a few hundred watts per panel/GT inverter... And those are designed to plug into an existing multi-outlet branch circuit. If you have (in the US) a 15 amp breaker on 14 AWG wire and plug in (upwards of 1,800 watts) of plug and play array, you have almost 30 amps available on a 14 AWG 15 amp rated circuit. If somebody else starts plugging into the branch circuit (hair driers, appliances, etc.), there is >> 15 amps available on that string of outlets and it is very easy to start a fire if "something goes wrong".

With a 240 VAC Enphase circuit, the Electric Drier plug is generally a single outlet on a branch circuit--So one could argue that that form of plug & play is "safe(er)"... But, it still does not meet the grounding requirements for the array... Plus any solar power that enters a building (without an external disconnect--as I recall) requires EMT (conduit) to bring the wiring into the the home--You just cannot run an SOJ cord down the side of the building and in through a window or hole drilled into the wall.

Safety is a "Layered" approach, and for every instance I can bring up (say somebody has an old 60 amp service and puts a 20 amp Enphase in, that will exceed the safety ratings of the main panel)--You can say you are talking about a few hundred amps of array, not 2 kW--And you would be correct.

And such a system would work "relatively safely" until something "goes wrong" (slice in a power cord, weather checking because did not use UV rated insulation, chewing animal started gnawing on cables, etc.).

Yes, there are probably thousands of "guerrilla" GT and Off Grid power systems that have never had a problem. And there are hundreds (or thousands) of GT systems that have been installed with building permits (correctly and incorrectly) that have still caught fire.

Most of us in North America live in a heavily regulated home (beginning to resent that more and more myself). But the NEC (national electric code) and the various UL type agencies (Nationally Recognized Testing Laboratories) are there to create both "traceable" safety, safety standards, and a "layered" safety approach. If you start going against "code", you are beginning to violate many of the assumptions that code makes (using non UL-Listed components--Code assumes they will "fail safely"--What if the do not).

We try to be safe with our recommendations here... If you ask why--we will tell you why.

If you ask "how do I do xyz"... We will probably first give you a reason why xyz is not safe, and here are some alternatives. But we will still try to answer the questions once we have made those initial warnings (we are a practical bunch here--we don't want to see anyone get hurt, but people still have questions and are, in the end, responsible for their own choices in life).

But, if somebody wants to argue something is safe but against code--They better have some very good reasons to back that up (I argue that the DC Ground Fault System used in NEC for Arc Fault Protection is highly unsafe and makes for many times more problems than "arc faults" themselves). But we try to argue those from a technical perspective--Not from a "what can I get away with and not get caught" point of view.

-Bill

BB.

Re: Poor mans grid-tied system.. The plans.. Fire hazard? Or will it actually work?

pivot.enabled wrote: »

Also there is another simple option.....

Install a transfer panel and weatherproof inlet plug as can be legally utilized with a generator... All permitted, all legal and *relatively* low cost.

Again this provides the OP with cheap start up cost and expandability as his budget allows.

In my city (California), as far as I know, it is illegal to connect a permanently attached piece of equipment with a plug (central furnace--my installer just got 'busted" for that one, air compressors, generators, etc.). If they are permanently connected to the building/ground, then they must be "hardwired" and grounded per code.

-Bill

Cariboocoot

Re: Poor mans grid-tied system.. The plans.. Fire hazard? Or will it actually work?

I can think of dozens of ways to do safe and undetectable GTI installs. But you will never see me explaining them on a public forum because they are illegal. That gets people in trouble one way or another and we're not having it here.

pivot.enabled

Re: Poor mans grid-tied system.. The plans.. Fire hazard? Or will it actually work?

Yes I am not assuming that it would be permanently connected, but your comments are well taken and to the point. Thanks.

pivot.enabled

Re: Poor mans grid-tied system.. The plans.. Fire hazard? Or will it actually work?

Cariboocoot wrote: »

I can think of dozens of ways to do safe and undetectable GTI installs. But you will never see me explaining them on a public forum because they are illegal. That gets people in trouble one way or another and we're not having it here.

Right. But I assert that it can be done legally WITH A PLUG. Also I would rather address the OPs questions without insulting their intelligence. If something is not advisable tell them why, from a technical and legal perspective.

BB.

Re: Poor mans grid-tied system.. The plans.. Fire hazard? Or will it actually work?

"Standard" solar panels are pretty fragile devices--They are roughly 1/8" think tempered glass (single weight). And any scratch/hard knock, and you have the entire glass sheet shattering into a piece of modern art.

Temporary installations tend to have issues with Wind Loading (can be hundred pounds or more of wind loading per panel)--So simple A frames staked to the ground is frequently not "good enough" for a semi-permanent installation. Plus panels over ~175 watts usually need two people to move them around without risking damage. So, they are not easily portable in any sense (pack-up for installation at the next house).

And if mounted directly on the ground, flying debris from lawn mowers and kids playing make ground mount panels nice targets.

There is no good way to temporary roof mount an array--You either do it right or you add to the neighborhood flying debris the next time a wind storm (or worse) comes by (neighbors would not be happy to find your solar panels in their sliding glass door have taken out their arrays either).

Some folks have may portable emergency power systems with a box and a single 140 watt panel, or several panels+battery bank mounted on wheeled carts (or even towed trailers)--But this is another set of solutions that kind of support temporary emergency use.

But then--We get back into what is that short term usage. I have multiple times here worked out the difference between a "trailer" loaded with solar panels + battery bank + inverters vs a trailer with small(er) genset and a few hundred gallons of fuel--And just from a weight/performance point of view, solar does not even break even until you got 6-12 months of service (i.e., it is cheaper and weighs less to put a Honda eu2000 1,600 watt genset and 400 gallons of gasoline on a trailer than the equivalent of solar panels+battery banks). And the Honda will run on 2-4 gallons of fuel per day--400 gallons will last 3-6 months (add some oil for a change every 4 days, and a second eu2000i for hot spare).

To get 1,500 watts * 24 hours per day from a solar array, you would need around a 17 kW solar array and a 3,750 AH @ 48 volt battery bank. That is no small system. Over 10,000 lbs for just the batteries (400 gallons of gasoline is only ~2,400 lbs).

-Bill

ggunn

Re: Poor mans grid-tied system.. The plans.. Fire hazard? Or will it actually work?

pivot.enabled wrote: »

Also there is another simple option.....

Install a transfer panel and weatherproof inlet plug as can be legally utilized with a generator... All permitted, all legal and *relatively* low cost.

Again this provides the OP with cheap start up cost and expandability as his budget allows.

The only problem with that is that it will not work. When the transfer switch is in the "grid" position, the PV is not connected to anything. When the transfer switch is in the "generator" position, the PV is connected to the house wiring but will not turn on because there is no reference voltage from the grid. There is no legal way to connect a transfer switch which will allow a generator (or in this case, a PV system) to be connected to the grid.

Plug in GT PV systems are 1) illegal, and 2) unsafe.

Cariboocoot

Re: Poor mans grid-tied system.. The plans.. Fire hazard? Or will it actually work?

pivot.enabled wrote: »

Right. But I assert that it can be done legally WITH A PLUG. Also I would rather address the OPs questions without insulting their intelligence. If something is not advisable tell them why, from a technical and legal perspective.

No, the NEC does not allow a GTI to be connected in any manner other than hardwiring to a dedicated line.

The reasons why have been explained multiple times in this thread and others like it on the forum. it's getting tedious.

pivot.enabled

Re: Poor mans grid-tied system.. The plans.. Fire hazard? Or will it actually work?

BB. wrote: »

"Standard" solar panels are pretty fragile devices--They are roughly 1/8" think tempered glass (single weight). And any scratch/hard knock, and you have the entire glass sheet shattering into a piece of modern art.

Temporary installations tend to have issues with Wind Loading (can be hundred pounds or more of wind loading per panel)--So simple A frames staked to the ground is frequently not "good enough" for a semi-permanent installation. Plus panels over ~175 watts usually need two people to move them around without risking damage. So, they are not easily portable in any sense (pack-up for installation at the next house).

And if mounted directly on the ground, flying debris from lawn mowers and kids playing make ground mount panels nice targets.

There is no good way to temporary roof mount an array--You either do it right or you add to the neighborhood flying debris the next time a wind storm (or worse) comes by (neighbors would not be happy to find your solar panels in their sliding glass door have taken out their arrays either).

Some folks have may portable emergency power systems with a box and a single 140 watt panel, or several panels+battery bank mounted on wheeled carts (or even towed trailers)--But this is another set of solutions that kind of support temporary emergency use.

But then--We get back into what is that short term usage. I have multiple times here worked out the difference between a "trailer" loaded with solar panels + battery bank + inverters vs a trailer with small(er) genset and a few hundred gallons of fuel--And just from a weight/performance point of view, solar does not even break even until you got 6-12 months of service (i.e., it is cheaper and weighs less to put a Honda eu2000 1,600 watt genset and 400 gallons of gasoline on a trailer than the equivalent of solar panels+battery banks). And the Honda will run on 2-4 gallons of fuel per day--400 gallons will last 3-6 months (add some oil for a change every 4 days, and a second eu2000i for hot spare).

To get 1,500 watts * 24 hours per day from a solar array, you would need around a 17 kW solar array and a 3,750 AH @ 48 volt battery bank. That is no small system. Over 10,000 lbs for just the batteries (400 gallons of gasoline is only ~2,400 lbs).

-Bill

Yes, all very good points Bill.

pivot.enabled

Re: Poor mans grid-tied system.. The plans.. Fire hazard? Or will it actually work?

Cariboocoot wrote: »

No, the NEC does not allow a GTI to be connected in any manner other than hardwiring to a dedicated line.

The reasons why have been explained multiple times in this thread and others like it on the forum. it's getting tedious.

Cariboo, the problem is that you are wrong. The NEC DOES allow a GTI to be plugged in. There, that should remove some of the tedium!

Cariboocoot

Re: Poor mans grid-tied system.. The plans.. Fire hazard? Or will it actually work?

pivot.enabled wrote: »

Cariboo, the problem is that you are wrong. The NEC DOES allow a GTI to be plugged in. There, that should remove some of the tedium!

Quote the appropriate section then.

pivot.enabled

Re: Poor mans grid-tied system.. The plans.. Fire hazard? Or will it actually work?

Cariboocoot wrote: »

Quote the appropriate section then.

I'll do better than that. I will point you at a company whose entire business model is based on it.

http://www.clarianpower.com/solar.html

Also, I would turn your question around. The only requirement I can find on plugging in the inverter output has to do with a common ground. Show me ANY restriction against it.

Also just to be clear I have NOTHING to do with the referenced company

solar_dave

Re: Poor mans grid-tied system.. The plans.. Fire hazard? Or will it actually work?

pivot.enabled wrote: »

I'll do better than that. I will point you at a company whose entire business model is based on it.

http://www.clarianpower.com/solar.html

Also, I would turn your question around. The only requirement I can find on plugging in the inverter output has to do with a common ground. Show me ANY restriction against it.

Also just to be clear I have NOTHING to do with the referenced company

Yeah but it is not available. Why? It doesn't meet code I am sure, it would not be to tough to throw this together for sale.

Availability
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jaggedben

Re: Poor mans grid-tied system.. The plans.. Fire hazard? Or will it actually work?

pivot.enabled wrote: »

Right. But I assert that it can be done legally WITH A PLUG.

Nope.

State laws vary in their exactness, but it's a pretty sure thing that it is illegal everywhere to install equipment that is capable of backfeeding the grid without getting permission from the utility. In states without net-metering laws it is illegal, period. Makes no difference what type of equipment or how it is installed. If not a violation of state-law, then it's a violation of your contract with the utility.

Further, where the NEC or something close to it is the law (most places), it is illegal to install equipment without following the instructions. So installing Enphase with a plug would be illegal. Further, your apparent idea that anything is legal just because it's plugged in does not hold water.

As I stated in a similar thread, if one has the electrical knowledge to safely install a plug for grid-tie inverters, then one also has the knowledge to install the inverters properly to a breaker in a panelboard. There's no benefit to wasting time and money on the plug.

ggunn

Re: Poor mans grid-tied system.. The plans.. Fire hazard? Or will it actually work?

pivot.enabled wrote: »

I'll do better than that. I will point you at a company whose entire business model is based on it.

http://www.clarianpower.com/solar.html

Also, I would turn your question around. The only requirement I can find on plugging in the inverter output has to do with a common ground. Show me ANY restriction against it.

Also just to be clear I have NOTHING to do with the referenced company

Just because someone built a website to sell something does not mean that it's NEC compliant. Most reputable equipment providers show their UL, etc. listings; these guys only say that they are working on it.

solar_dave

Re: Poor mans grid-tied system.. The plans.. Fire hazard? Or will it actually work?

If you think the utilities don't take this seriously then you need to read these documents.
https://www.aps.com/library/solar%20renewables/InterconnectReq.pdf
https://www.aps.com/library/renewables/PVSystemchecklist.pdf

There are about 10 more requirement docs here:
https://www.aps.com/en/globalservices/installers/Pages/resources-for-green-energy-installers.aspx


Edit and oh I especially like this one. It is the check list the utility will use.

https://www.aps.com/library/solar%20renewables/ResInspectChkList.pdf

solar_dave

Re: Poor mans grid-tied system.. The plans.. Fire hazard? Or will it actually work?

Here is the NEC 2011 pdf for the code requirements:
http://classdat.appstate.edu/FAA/TEC/scanlindm/2011%20national%20Electric%20Code/National%20Electrical%20Code%202011.pdf

see section 690

My AHJ was even more restrictive than the 2008 NEC code and it looks like they were working off drafts of the 2011 code for much of what they wanted.

pivot.enabled

Re: Poor mans grid-tied system.. The plans.. Fire hazard? Or will it actually work?

Yes that is true. What I take issue with is the blanket statement that a plug in this case is not up to code or illegal. I disagree. The answer is that Coots does not know with certainty whether it is legal or not. The appropriate answer is "I don't know" and until this is definitively resolved by the NEC the question will keep coming up.... Tediously or no. I would also agree wiring the circuit dedicated is not a big deal. Frankly it will probably have a disconnect anyhow so really from a safety perspective... whatever! As with any circuit that anything could get plugged into it is attached to a breaker so ultimately this issue will boil down to safety and market demands and NEC will specifically allow it. In the interim though it is neither specifically disallowed nor is it unsafe.

Cariboocoot

Re: Poor mans grid-tied system.. The plans.. Fire hazard? Or will it actually work?

The appropriate answer is: if you say it meets code quote the section of code that permits it, not some web site trying to sell inverters.

The curious paradox here is that these types of inverters are in fact legal to sell. They are not legal to install. No inspector worth his salary would permit it either.

solar_dave

Re: Poor mans grid-tied system.. The plans.. Fire hazard? Or will it actually work?

pivot.enabled wrote: »

Yes that is true. What I take issue with is the blanket statement that a plug in this case is not up to code or illegal. I disagree. The answer is that Coots does not know with certainty whether it is legal or not. The appropriate answer is "I don't know" and until this is definitively resolved by the NEC the question will keep coming up.... Tediously or no. I would also agree wiring the circuit dedicated is not a big deal. Frankly it will probably have a disconnect anyhow so really from a safety perspective... whatever! As with any circuit that anything could get plugged into it is attached to a breaker so ultimately this issue will boil down to safety and market demands and NEC will specifically allow it. In the interim though it is neither specifically disallowed nor is it unsafe.

But if you do it correctly it will never be accepted by the local inspector or the utility. At least not here!

BB.

Re: Poor mans grid-tied system.. The plans.. Fire hazard? Or will it actually work?

We have seen a hand full of websites that advertise Plug & Play GT solar--And everyone I have seen has either said not yet for sale pending regulatory approval--Or waved their hands but could not give a File Number (required for NRTL Listed devices before they can be used). Over the years, I have seen fire department inspections threaten to red tag a business if there was a non-UL listed coffee maker in the break room. New York City in decades past was notorious for shutting down, taking wire cutters to power cords of non-compliant devices and such.

Interestingly enough, under the fire department's secretary's desk was the worst accumulation of three was power cubes my father had ever seen (this was nearly 5 decades ago--he repaired office equipment).

As soon as one of these "plug & play" sets can give us a UL (or NRTL) File Number--We can go right on the web and confirm that this is the case.

We have already talked publicly with, at least, two different companies about Plug & Play systems. It is real simple, I don't have to quote chapter and verse of the NEC on what is or is not "legal". All I have to ask for is the NRTL File Number (UL, ETL, etc.). Have a file number, then we know how to install (there are different listing headings a product can be listed under--In times past, I had seen companies try to "slip" products under a "toy" Listing just to get a NRTL file number--Only to find out that it was useless for use in a NEC Compliant installation/product).

We have had people tell us the Listing Numbers were proprietary information. Yes, the real/full NRTL files can contain proprietary information and may not be publicly released. However, the file numbers are public and so is a very sort description of the product.

For example, a Listed Plug&Play product can (and will) use UL Listed and Registered Components. But just because the product may use (for example) an Enphase listed GT Inverter... It does not mean the "new product" (solar panels+Enphase+wiring+plug+rack) will be. The "product" would have its own listing number (if sold as a product).

By the way, if there is an instruction manual, normally the NRTL Listing will include the manual too (i.e., if installed per mfg. instructions, the device Listing is valid). Unless the Enphase instructions say to put a 30 amp drier plug on the end of the cable, the electrician cannot do that and install the product "per code" / per Listing file.

-Bill

pivot.enabled

Re: Poor mans grid-tied system.. The plans.. Fire hazard? Or will it actually work?

BB. wrote: »

We have seen a hand full of websites that advertise Plug & Play GT solar--And everyone I have seen has either said not yet for sale pending regulatory approval--Or waved their hands but could not give a File Number (required for NRTL Listed devices before they can be used). Over the years, I have seen fire department inspections threaten to red tag a business if there was a non-UL listed coffee maker in the break room. New York City in decades past was notorious for shutting down, taking wire cutters to power cords of non-compliant devices and such.

Interestingly enough, under the fire department's secretary's desk was the worst accumulation of three was power cubes my father had ever seen (this was nearly 5 decades ago--he repaired office equipment).

As soon as one of these "plug & play" sets can give us a UL (or NRTL) File Number--We can go right on the web and confirm that this is the case.

We have already talked publicly with, at least, two different companies about Plug & Play systems. It is real simple, I don't have to quote chapter and verse of the NEC on what is or is not "legal". All I have to ask for is the NRTL File Number (UL, ETL, etc.). Have a file number, then we know how to install (there are different listing headings a product can be listed under--In times past, I had seen companies try to "slip" products under a "toy" Listing just to get a NRTL file number--Only to find out that it was useless for use in a NEC Compliant installation/product).

We have had people tell us the Listing Numbers where proprietary information. Yes, the real/full NRTL files can contain proprietary information and may not be publicly released. However, the file numbers are public and a very sort description of the product are not.

For example, a Listed Plug&Play product can (and will) use UL Listed and Registered Components. But just because the product may use (for example) an Enphase listed GT Inverter... It does not mean the "new product" (solar panels+Enphase+wiring+plug+rack) will be. The "product" would have its own listing number (if sold as a product).

By the way, if there is an instruction manual, normally the NRTL Listing will include the manual too (i.e., if installed per mfg. instructions, the device Listing is valid). Unless the Enphase instructions say to put a 30 amp drier plug on the end of the cable, the electrician cannot do that and install the product "per code" / per Listing file.

-Bill

Thanks, that is an excellent answer Bill, but I think it also puts it into perspective. Each of the component parts of the system can be legal and permitted but the system as a unit is not legal. Plugging a non UL listed coffee maker into a circuit is not legal, nor is wiring a UL listed device (Enphase inverter for example) in a non-manufacturer approved way legal. But on that basis if I refer to my old popular mechanics encyclopedia set, there is a long list of plans for building various devices, none of which can legally be plugged in on that basis. Plenty of ingenious Americans nevertheless designed, built and plugged those things in and they worked. Pretty much all of the devices described in those encyclopedias were available commercially and I suppose somebody could have said "why don't you quit being so cheap and go buy one!" but the fact of the matter is that the people building them either couldn't afford a commercial unit or wanted the satisfaction of figuring it out and building it themselves. I admire those people and I prefer to give them honest answers. So is it safe? Well it's about as dangerous (less so I'd say) as plugging in your non UL listed coffee machine! - Thanks!

BB.

Re: Poor mans grid-tied system.. The plans.. Fire hazard? Or will it actually work?

Well, many times, the unlisted units are less safe. I posted a link to a fire caused by poorly constructed solar panels connected to a Listed GT Inverter. Panels lasted something like a few weeks or months, then caught fire on the roof.

Many of the ~350 Watt plug and play inverters have been tested by folks here and found that they run very hot (unsafely hot) when operated to specifications.

And, when you connect to the power grid--You have responsibilities to the folks that provide the power and insure your home (and your neighbors).

You can argue that my home, my castle--And to a degree I would agree with you. However, in some countries (like parts of Canada), the power company believes they can regulated anything that plugs into utility power (probably similar to what we see fire/building inspectors do in the US).

However, when you actually start pumping energy into the grid--Many/most utilities have very firm set of requirements. You have to have a building permit (or prior approval by the utility if no local building inspectors), you have to carry liability insurance, you have to let the utility inspect/test your system, and you have to have a billing agreement/contract for GT Solar power (and in many cases, you have to have a different power meter--Some meters will "never turn backwards", some will even bill you for power you send to the grid (meter only turns forwards). Some meter will report if you are sending power to the grid and the utility has the "right" to cut power to your home if you did it without approvals.

Heck, it is "easy" to send power to the grid. Take an induction motor and spin it with a wind/water turbine or even a gasoline motor. When it spins faster than the native frequency (say 1,800 RPM for a 60 Hz power line), you will begin to send power to the grid very nicely.

But--this is the world we live in today... In theory, if I tell my utility to pull my meter because I don't want to buy their power anymore but use off grid solar--In California, the utility can charge me large amounts of money for "stranding charges"... Basically, they took out a bunch of loans for capital projects "in my name"--And they want me to pay them back for the "loss of revenue" from me. Is it fair--perhaps not. Is it legal, you bet your bottom dollar it is (as far as the courts are concerned).

Listing a product (in the US) does not guarantee that the product will function per the specifications... It only means that it meets the "UL Safety Requirements" and it should "fail safely"...

As I said, yes, you can connect all this stuff up, and possibly even be pretty safe. Or you can use all the permitting/UL Listings/licensed electricians and still get an Arc Fault on the roof and start a fire. (solar panels are notoriously difficult to protect against arc faults. solar panels are "current limited" so a fuse/breaker will not trip if there is a short, and DC power sustains arcs very nicely compared with AC power.).

NEC and others are still working on trying to figure out the proper level of safety even today (similar with fire codes--adding requirements for roof space/walking space for fire fighters to access panels and bare roofs to punch ventilation holes, etc.).

Go out of the "comfort zone" for code compliance, the more likely something can go seriously wrong.

Planes still fall out of the sky for many reasons. And we have the whole experimental aircraft designation (typically only non-commercial aircraft can be "experimental" which allow the owners to work on their planes directly without going through the whole FAA paperwork/certified mechanic stuff).

Should there be an "experimental" RE Power designation--Perhaps... But I am not sure I see a pressing need for such.

-Bill

icarus

Re: Poor mans grid-tied system.. The plans.. Fire hazard? Or will it actually work?

Clearly you are going to do what you are going to do. I would add however, that instead of asking us to supply chapter and verse code sections and local utility regs across the continent, it should be incumbent on you to find somewhere, somehow that shows that it is legal in some jurisdiction.

Like we started in this thread many months and ages ago, there are always people who wish to do solar on the cheap, and quite often they get what they pay for.

Finally, for all the trouble of dutching in a bootlegged installation to save a few dollars, for my money, I would invest in high(er) efficiency devices, find and kill phantom loads, and reduce consumption over all.

Icarus

inetdog

Re: Poor mans grid-tied system.. The plans.. Fire hazard? Or will it actually work?

solar_dave wrote: »

Yeah but it is not available. Why? It doesn't meet code I am sure, it would not be to tough to throw this together for sale.

A. The website indicates that the device is not available.
B. The website is copyright 2011. The device is still not available two years later?
C. I suspect that their principle activity has always been raising investment money and that is the main purpose of the website.
D. If it becomes available, it will have to be UL listed to be installed (but not to be sold!!). I doubt that will ever happen.

pivot.enabled

Re: Poor mans grid-tied system.. The plans.. Fire hazard? Or will it actually work?

Interesting you should mention airplanes... I fly a Cessna 177 and mostly do my own work (has to be inspected by an A&P with IA of course). Much though I love my 177 I would rather own an experimental (RV to be precise) because then I could sign off my own repairs

The core of FAA regulations with regard to the "experimental" designation and in fact other areas tend to revolve around the risk you pose to others. I tend to take a libertarian view of things so I think that that makes sense. Killing a power line worker because you dropped power on the grid when it shouldn't be there = Criminal.

Anyways, thanks for the answers.

BB.

Re: Poor mans grid-tied system.. The plans.. Fire hazard? Or will it actually work?

I used to fly and work on airplanes as a hobby--But getting a "real job" and married put an end to that.

-Bill

ggunn

Re: Poor mans grid-tied system.. The plans.. Fire hazard? Or will it actually work?

pivot.enabled wrote: »

Yes that is true. What I take issue with is the blanket statement that a plug in this case is not up to code or illegal. I disagree. The answer is that Coots does not know with certainty whether it is legal or not. The appropriate answer is "I don't know" and until this is definitively resolved by the NEC the question will keep coming up.... Tediously or no. I would also agree wiring the circuit dedicated is not a big deal. Frankly it will probably have a disconnect anyhow so really from a safety perspective... whatever! As with any circuit that anything could get plugged into it is attached to a breaker so ultimately this issue will boil down to safety and market demands and NEC will specifically allow it. In the interim though it is neither specifically disallowed nor is it unsafe.

The current available in case of an overload on the circuit where a plug in inverter is installed is the rating of the breaker in the panel feeding the circuit plus the rating of the breaker at the inverter. If the sum of these OCPD ratings exceed the appropriately derated ampacity of the wiring in the circuit by more than 20%, it is a fire hazard and therefore unsafe. The NEC2011 reference is 705.12(D)(2), colloquially known as the "120% rule". I'm also pretty sure that if the inverter is not plugged into the opposite end of the circuit from the panel, you don't get that 20% margin.

Blackcherry04

Re: Poor mans grid-tied system.. The plans.. Fire hazard? Or will it actually work?

I don't see it as a Issue at all, the Inverter is a " Power Source " as such it already falls in the NEC code, it's backfeeding a circuit. Plugged in the way it is it violates many parts of the code, to numerous to mention. I think everyone knows that plugging in a generator into a wall receptacle is Illegal, a Inverter is the same. Is it done ??, heck yeah, all the time, still doesn't make it legal.

In the case of a Enphase you'd have to have a 240 receptacle, that would have to be " female " that means the Inverter would have to have a naked Male plug, that wouldn't be legal, nor would one for 120 v be.
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