PsyCLown Posted June 22, 2023 Share Posted June 22, 2023 Hey all, So I have a few questions regarding the Luxpower SNA5000 inverters. With 2 or more in parallel, will this increase the maximum charge rate from the grid when charging the batteries? The datasheet states 60A charge rate from grid - would this figure increase? Would one be able to charge batteries quicker with multiple inverters in parallel? Also with multiple batteries and multiple inverters, what is the best practice to connect the batteries? Should one connect the batteries to a busbar and then run the same length cables from the bus bar to each inverter? Then with regards to the PV side, the datasheet states 3200W max recommended per MPPT, what would happen if one were to wire up panels which exceed a theoretical max of 3200W and everything aligns and the panels are producing more than 3200W, however the string voltage and current are within the limits - would it fry the MPPT? Would the excess power be clipped? Quote Link to comment Share on other sites More sharing options...
Scorp007 Posted June 22, 2023 Share Posted June 22, 2023 5 hours ago, PsyCLown said: Hey all, So I have a few questions regarding the Luxpower SNA5000 inverters. With 2 or more in parallel, will this increase the maximum charge rate from the grid when charging the batteries? The datasheet states 60A charge rate from grid - would this figure increase? Would one be able to charge batteries quicker with multiple inverters in parallel? Also with multiple batteries and multiple inverters, what is the best practice to connect the batteries? Should one connect the batteries to a busbar and then run the same length cables from the bus bar to each inverter? Then with regards to the PV side, the datasheet states 3200W max recommended per MPPT, what would happen if one were to wire up panels which exceed a theoretical max of 3200W and everything aligns and the panels are producing more than 3200W, however the string voltage and current are within the limits - would it fry the MPPT? Would the excess power be clipped? Not worth it to try and find out what will happen if you exceed the 3200W PV. With multiple inverters what would the reason be to not connect the right value to each one as the manual shows you when using more than 1 inverter? Quote Link to comment Share on other sites More sharing options...
PsyCLown Posted June 22, 2023 Author Share Posted June 22, 2023 (edited) 43 minutes ago, Scorp007 said: Not worth it to try and find out what will happen if you exceed the 3200W PV. With multiple inverters what would the reason be to not connect the right value to each one as the manual shows you when using more than 1 inverter? Was more for curiosity, looking at 5x 620W panels per MPPT which puts the theoretical max at 3100W. My worry is if there were to be some cloud lensing and it pushes the power to over 3200W - what will happen? Regarding the batteries for parallel in the manual, looks as if all batteries get connected to each inverter, I am wondering how most do this in such a setup? What are the options available and then also curious about the charge speeds if that would increase? Edited June 22, 2023 by PsyCLown Quote Link to comment Share on other sites More sharing options...
Zombie Posted June 22, 2023 Share Posted June 22, 2023 47 minutes ago, Scorp007 said: Not worth it to try and find out what will happen if you exceed the 3200W PV. With multiple inverters what would the reason be to not connect the right value to each one as the manual shows you when using more than 1 inverter? Isn't it better to oversize the arrays anyway? https://unboundsolar.com/blog/oversizing-pv-arrays Quote Link to comment Share on other sites More sharing options...
Scorp007 Posted June 22, 2023 Share Posted June 22, 2023 (edited) 49 minutes ago, PsyCLown said: Was more for curiosity, looking at 5x 620W panels per MPPT which puts the theoretical max at 3100W. My worry is if there were to be some cloud lensing and it pushes the power to over 3200W - what will happen? Regarding the batteries for parallel in the manual, looks as if all batteries get connected to each inverter, I am wondering how most do this in such a setup? What are the options available and then also curious about the charge speeds if that would increase? OK in that case it could be OK as cloud edge will be for a short period and MPPT should throttle it OK. There is also a limit around going over up to 15-20%. There are however some makes that won't tolerate it and switch of and/or become unstable. @Zombie It's easy to write a guide and say you can oversize by 20% yet the author will not be around if the system switches off. We have a brand that has been covered on the forum that becomes unstable when exceeding the max. Think of some posts where Canadian panels went 25% over what their maximum current and power would be. Edited June 22, 2023 by Scorp007 Zombie and PsyCLown 1 1 Quote Link to comment Share on other sites More sharing options...
PsyCLown Posted June 22, 2023 Author Share Posted June 22, 2023 10 minutes ago, Scorp007 said: OK in that case it could be OK as cloud edge will be for a short period and MPPT should throttle it OK. There is also a limit around going over up to 15-20%. There are however some makes that won't tolerate it and switch of and become unstable. Am I correct in stating that the MPPT would throttle it by clipping the current as the voltage cannot be changed by the MPPT? 35 minutes ago, Zombie said: Isn't it better to oversize the arrays anyway? https://unboundsolar.com/blog/oversizing-pv-arrays This is the other thing, quite a few do oversize their arrays. Although if the MPPT would throttle it, not too much of an issue then I guess. I know that generally the MPPT would clip the current if that is higher than what the MPPT is rated for, the big one to consider is the voltage from the PV array as the MPPT cannot reduce the voltage and too high I believe will blow the MPPT - the cold leads to higher voltage, so one should work out the VOC and ensure that the voltage is still within the limits on the coldest day one is likely to experience. Quote Link to comment Share on other sites More sharing options...
Herman S Posted June 24, 2023 Share Posted June 24, 2023 Hi I have similar question. The 5kw hybrid luxpower has 2 ports for panels.i have 6 panels in series directly to pv1 and bridged to pv2. On Pv1 and pv2.on the tester I get 288V but inverter state 238V currently . Panels rate at 545 x 6 =3270w and 48.5v X6 = 291 Panel give me an average of 400w each because of placement. 2400w total. Recently I noticed that my V and panel average got lower last few days. I then get a max of 120v / 1230W. If I reset system, or pull the fuses from main system.replace them they immediately go back to 291v /2400w. Why would this happen? Must pv1/2 be bridge or can I have them unbridged? Is this maybe a setting I have wrong? Fuse holders maybe not to standard? Quote Link to comment Share on other sites More sharing options...
TaliaB Posted June 24, 2023 Share Posted June 24, 2023 (edited) 3 hours ago, Herman S said: Must pv1/2 be bridge or can I have them unbridged? They need to be unbridged just used pv input A+and A- the second mppt input is then for future expansion. Mppt startup voltage 100v, mppt voltage range 120-385v, Max open curcuit voltage 480v. If the voltage drops intermittently i don't think it is a setting. Check your panel wiring for loose connections up to the mppt1 input. Edited June 24, 2023 by TaliaB Quote Link to comment Share on other sites More sharing options...
Herman S Posted June 26, 2023 Share Posted June 26, 2023 On 2023/06/24 at 4:46 PM, TaliaB said: They need to be unbridged just used pv input A+and A- the second mppt input is then for future expansion. Mppt startup voltage 100v, mppt voltage range 120-385v, Max open curcuit voltage 480v. If the voltage drops intermittently i don't think it is a setting. Check your panel wiring for loose connections up to the mppt1 input. Hi. Thanks for feedback. So I did all this and checked the wire to inverter. Set it to first mppt. This morning I went to check voltage. It's starts every morning on 120v. I used the tester and it's 120v. As I pull fuses it go up to 291. When I re-engage fuses it starts at 291V and with in 1min it's steady on 238V. It stay at this till sun drops and steadily drops . Quote Link to comment Share on other sites More sharing options...
PsyCLown Posted June 26, 2023 Author Share Posted June 26, 2023 49 minutes ago, Herman S said: Hi. Thanks for feedback. So I did all this and checked the wire to inverter. Set it to first mppt. This morning I went to check voltage. It's starts every morning on 120v. I used the tester and it's 120v. As I pull fuses it go up to 291. When I re-engage fuses it starts at 291V and with in 1min it's steady on 238V. It stay at this till sun drops and steadily drops . The fact that your inverter and tester both show the lower voltage points to it not being an issue with the inverter. I'd say check for a loose connection somewhere, the fact the fuses seem to cause it to go up in voltage makes me suspect that may be a good area to start checking for something loose. There is also the possibility of shading in the morning / not enough sun for high voltage and perhaps it is just a coincidence that after putting the fuse back in the voltage goes up - however once I could understand, if it consistently happens then that does not make sense either. Quote Link to comment Share on other sites More sharing options...
Herman S Posted June 26, 2023 Share Posted June 26, 2023 28 minutes ago, PsyCLown said: The fact that your inverter and tester both show the lower voltage points to it not being an issue with the inverter. I'd say check for a loose connection somewhere, the fact the fuses seem to cause it to go up in voltage makes me suspect that may be a good area to start checking for something loose. There is also the possibility of shading in the morning / not enough sun for high voltage and perhaps it is just a coincidence that after putting the fuse back in the voltage goes up - however once I could understand, if it consistently happens then that does not make sense either. I have no shade problem and I think it might be a connection problem. heat and cold explanation on connectors maybe? it only started this last week sometime when we got minus temperatures. ill open all connection the weekend and put in a compound for better connection and with the main fuse holder(I believe MY ACDC fuse holders installed are not the best). If this still persist ill have to check each panel fuse as last resort. Quote Link to comment Share on other sites More sharing options...
TaliaB Posted June 26, 2023 Share Posted June 26, 2023 19 minutes ago, Herman S said: I have no shade problem and I think it might be a connection problem. heat and cold explanation on connectors maybe? it only started this last week sometime when we got minus temperatures. ill open all connection the weekend and put in a compound for better connection and with the main fuse holder(I believe MY ACDC fuse holders installed are not the best). If this still persist ill have to check each panel fuse as last resort. Feel the outer case of the fuses if they are becoming hot you might have higher resistance on the fuse holders i have found at 10 amps some fuse holders become hotter than others a indication of low quality fuse holders. I agree ACDC definitely not good quality. Quote Link to comment Share on other sites More sharing options...
TaliaB Posted June 26, 2023 Share Posted June 26, 2023 These fuse holders comply with standard IEC60947-3 Quote Link to comment Share on other sites More sharing options...
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