raydas
Solar Devotee
Posts: 166
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Post by raydas on Jan 6, 2020 16:15:59 GMT
Thanks for the cautionary note. I have smoked enough wires to be extremely cautious when working with this stuff. That is why I will be testing this stuff before I put it to actual use.
I have not pushed the "buy" button yet, but if and when I do get it and test it, I will report back the results.
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Post by mediadogg on Jan 6, 2020 16:27:39 GMT
Great. I did go and look at the Amazon listings and reviews. I did see a couple of troubling reviews, including one where the unit burned up. But I have had equipment burn up before also. I was surprised that I did not see any comments cautioning about back feed into the grid or about electrical code violations or legality. If I can be convinced that the risk is not there, then I might reconsider this solution, although I would probably want a better built unit. Actually, my use would probably be for creating a parallel output from two off-grid inverters. This would greatly simplify my systems if I can be convinced that these units work properly. I will wait eagerly for your report.
But if I can safely connect the output of my Lycan with the output of my Samlex inverters, then I could use this solution.
One problem: the unit claims to track the phase of the mains, but it would seem to me that the voltage output would also need to be tracked. What if the inverter is putting out 120VAC and the mains is putting out 115VAC, or vice-versa? My Samlex inverters put out 120VAC dead solid. But my Lycan units put out 110VAC. So maybe I could not mix them - but instead, maybe double up on the same brand, which would still be useful.
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Post by mediadogg on Jan 6, 2020 16:41:05 GMT
Also note the manufacturer cautions about using DC input. "Grid Tie Solar Inverter - Creative MPPT technology, efficiency more than 99%【Please do not use other voltage input, for example: (20V) or(45V) Please use 200W-1000W solar panel (Voc36-46V)】" The MPPT technology attempts to regulate the solar panel output for maximum power. PV output is "soft" - the voltage and current will vary greatly with the load. But a battery or DC power outputs are "stiff." They have their own internal regulation (or battery chemistry) which will try to maintain a steady voltage and will attempt to put out more current. This might shorten the life of both the inverter and / or the battery or DC power supply input. But then they give this advice for testing. Confusing to say the least.
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Post by bupkis on Jan 6, 2020 16:48:17 GMT
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Post by mediadogg on Jan 6, 2020 18:48:26 GMT
Wow! Thanks for that! I like that guy. I watched his video building his "Tesla" power wall battery pack. He puts all DIYers to shame with his mad skills, so I trust his analysis. Well, looks like I might be trying out one of those inverters someday. Live and learn.
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Post by mediadogg on Jan 6, 2020 21:30:25 GMT
Great. I did go and look at the Amazon listings and reviews. I did see a couple of troubling reviews, including one where the unit burned up. But I have had equipment burn up before also. I was surprised that I did not see any comments cautioning about back feed into the grid or about electrical code violations or legality. If I can be convinced that the risk is not there, then I might reconsider this solution, although I would probably want a better built unit. Actually, my use would probably be for creating a parallel output from two off-grid inverters. This would greatly simplify my systems if I can be convinced that these units work properly. I will wait eagerly for your report. But if I can safely connect the output of my Lycan with the output of my Samlex inverters, then I could use this solution. One problem: the unit claims to track the phase of the mains, but it would seem to me that the voltage output would also need to be tracked. What if the inverter is putting out 120VAC and the mains is putting out 115VAC, or vice-versa? My Samlex inverters put out 120VAC dead solid. But my Lycan units put out 110VAC. So maybe I could not mix them - but instead, maybe double up on the same brand, which would still be useful. Been thinking about this. Too risky. Unless the grid-tie inverters communicate with one another (such as the outdoor units with wireless), if you have more than one plugged into the mains, how can you be sure ALL of them will shut off. I think it would be possible for the output of one inverter to trick one or more other inverters into thinking the mains are still on, thereby leading to the risk of back feeding the grid while the power if off, putting workers at risk.
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raydas
Solar Devotee
Posts: 166
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Post by raydas on Jan 6, 2020 21:46:12 GMT
I watched the disassembly guy and the roof top guy video. Both implied that the $98 unit should not be run at full capacity, and of course, the unit should be in a weather proof enclosure. For me, that could be a problem, the full capacity aspect.
I will be using the unit inside of the house, so no weather proofing necessary. But I do plan to run it 24/7, from battery input. Now, how do determine at what capacity I should set it at. I might have to find a good adjustable voltage regulator, attach it to the battery supply, and set it for 18VDC or maybe 19VDC input to the $98 unit? I have some dht22 units laying around, maybe place a couple of these around the $98 unit, and data log the temps to see how warm the thing gets. I guess just a couple of thoughts.
bupkis, thanks for links.
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Post by mediadogg on Jan 6, 2020 22:00:04 GMT
Ok, I finally found a discussion of legality. Here. This forum claims that a "plug-n" grid tie inverter is illegal everywhere in the US and a total waste of money and a big risk. That is what I thought in the first place. Another article here. The confusion in the marketplace comes from the fact that people take availability on Amazon, Youtube and / or eBay as evidence that the product can be used legally however the customer wants to. Some uses are legal. Some are not. (think about guns as an obvious example in another context) I hereby state that I personally DO NOT plan to use a "plug-in" grid-tie inverter. Anybody else is welcome to do whatever they want and pay or enjoy the consequences. Can anybody provide a link that describes credible LEGAL APPROVAL of such a connection? And to raydas regarding your last question: see here: renogy.boards.net/post/5392 and another warning: here.
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raydas
Solar Devotee
Posts: 166
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Post by raydas on Jan 6, 2020 22:21:21 GMT
I took my finger off of the buy button. Sounded like a really good solution, but to good to be true. Have to look into something other solution(s).
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Post by tattoo on Jan 6, 2020 22:45:04 GMT
Ok, I finally found a discussion of legality. Here. This forum claims that a "plug-n" grid tie inverter is illegal everywhere in the US and a total waste of money and a big risk. That is what I thought in the first place. Another article here. Damn good info right there........... Thanks for posting it............ I wasn't sure in the beginning but it sounded like trouble to me..............
Hopefully this thread will help someone from getting electrocuted in the future........
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Post by Guest on Jan 6, 2020 22:49:35 GMT
[...] After reading some more of the $98 unit data sheet, I think the get even close to the 1000W rating, the input voltage will probably have to be around 20VDC, but hopefully I can narrow this down, when I do some tests. Keep in mind that the input current at 24 volt (for a inverter with a 120 volt AC output) is something like 42 amps.
1000 watts output at 120 volts requires an input of 50 amps at 20 volts.
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Post by tattoo on Jan 6, 2020 22:59:52 GMT
There is risk of death or injury to power company employees and risk of equipment damage if the inverter and the mains AC signal are not in phase. Since you mentioned this........ I've been wondering how much voltage will a 2000w inverter put into the lines if the power were to go out with one of the inverters he's talking about a quarter mile away from the inverter? Would it be 120v or something like 80v? Or would it stay constant?
It must be a good bit or they would be ok to use them................
Since you did a bunch of reading about this Dog I thought you might have run across this...........
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raydas
Solar Devotee
Posts: 166
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Post by raydas on Jan 6, 2020 23:41:54 GMT
I just remembered, that a couple of years back, the electric company did something with the electric meter so they could do remote readings of the meter. I wonder what other readings it is doing inside of the house. I do not want to take the chance that if I started to use a small grid-tie inverter, the company would find out and start some kind of inquisition. So, to be on the safe side, that will be the reason for not installing a grid-tie inverter.
I wonder how the professionally/legally installed grid-tie inverters prevent the electrocution of electric company employees, or for that matter setting your house on fire.
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Post by mediadogg on Jan 7, 2020 0:03:36 GMT
I just remembered, that a couple of years back, the electric company did something with the electric meter so they could do remote readings of the meter. I wonder what other readings it is doing inside of the house. I do not want to take the chance that if I started to use a small grid-tie inverter, the company would find out and start some kind of inquisition. So, to be on the safe side, that will be the reason for not installing a grid-tie inverter. I wonder how the professionally/legally installed grid-tie inverters prevent the electrocution of electric company employees, or for that matter setting your house on fire. You don't have to wonder. Just read about it. In simple terms, as I mentioned before and also referenced in some of those links I posted, there is special equipment that is installed at the service entrance under the auspices of NEC codes and the power company agreements you sign. This equipment turns off your inverter output when the mains power is interrupted. Grid-tie cannot be used for off-grid, so just when you need it most, your inverter and batteries are shut down. That prevents your system from electrifying the wires while people are working on them live. The transformers which step down the thousands of volts to 220VAC will be working in reverse, so that your inverter might cause thousands of volts to be present on the grid wiring. Now I can't speak to my over-dramatized statement about the risks. Even power company equipment can fail. There is no guarantee that even a correctly designed and installed system can prevent the system from failing in a way that causes damage. Again, as I said before, I sometimes wake up in a cold sweat thinking I should just disconnect all the DIY crap I have installed. We can't be certain about anything in life - just do our best to avoid risks.
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Post by tattoo on Jan 7, 2020 0:10:21 GMT
Again, as I said before, I sometimes wake up in a cold sweat thinking I should just disconnect all the DIY crap I have installed. We can't be certain about anything in life - just do our best to avoid risks. No need shutting it off..........As long as it is running well and safely keep it on....... It's saving you money why not use it? ? ?
Also, What you said above is EXACTLY correct that's why I keep my solar set up so SIMPLE...................... There is NO need for a bunch of useless BS............
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