November 14, 20232 yr I have limited space on my roof and was wondering if anyone with information would assist with what the minimum number of solar panels that one can have to be able to run with: a 8kVA Sunsynk Inverter. MPPT Input Voltage - 150Vd.c ~ 425Vd.c Max. PV Input Power - 10,400W PV Input Voltage - 370Vd.c (125Vd.c ~ 500Vd.c) Am looking at the Jinko 555w panels in particular and am thinking having 16 (8 per MPPT) would be my maximum given space limitations but is it possible to begin with: 6 x 555w on one mppt for a total of about 3,330w and; 12 x 250w on the other mppt for a total of 3,000w (these already exist) Would appreciate some wisdom.
November 14, 20232 yr 7 minutes ago, Moffat said: 6 x 555w on one mppt for a total of about 3,330w and; That should be fine, assuming the panels are Voc between 40 and 50V, then you should have 240 to 300V Voc and for Vmp, it should also fit for the specs of the inverter as for the 12 250W panels, you may need to split them into 6S2P, depending on their spacs, if they are also around 40V, let's say, then 12 in series would be 480V, which is probably not ideal, but at 240V (6 in series) should be find and the send set up 6 in parallel... EDIT: You really need to give the specs of the panels as well as that of the inverter, since my numbers above are thumbsuck and to get a realistic answer the specifications are needed, Vmp, Voc, Isc, then one can talk turkey as it were... Edited November 14, 20232 yr by Kalahari Meerkat
November 14, 20232 yr Author 1 minute ago, Kalahari Meerkat said: That should be fine, assuming the panels are Voc between 40 and 50V, then you should have 240 to 300V Voc and for Vmp, it should also fit for the specs of the inverter as for the 12 250W panels, you may need to split them into 6S2P, depending on their spacs, if they are also around 40V, let's say, then 12 in series would be 480V, which is probably not ideal, but at 240V (6 in series) should be find and the send set up 6 in parallel... Thanks for that. Last time I had my panels rewired, the labels were absolutely unreadable, so I guess a test meter would be the way to go in getting readings of each.
November 14, 20232 yr Author 26 minutes ago, Kalahari Meerkat said: That should be fine, assuming the panels are Voc between 40 and 50V, then you should have 240 to 300V Voc and for Vmp, it should also fit for the specs of the inverter as for the 12 250W panels, you may need to split them into 6S2P, depending on their spacs, if they are also around 40V, let's say, then 12 in series would be 480V, which is probably not ideal, but at 240V (6 in series) should be find and the send set up 6 in parallel... EDIT: You really need to give the specs of the panels as well as that of the inverter, since my numbers above are thumbsuck and to get a realistic answer the specifications are needed, Vmp, Voc, Isc, then one can talk turkey as it were... Those panels are from 2012 it may mean getting an installer to lift a couple up to try and ascertain that info.🤦♂️
November 14, 20232 yr 6 minutes ago, Moffat said: ?? Sorry @Moffat i did post about the 250w panels but there is quite a big Voc range from 23v to 37.7v Jinko. So would be best to measure your panels first before making a decision on connection configuration.
November 14, 20232 yr 24 minutes ago, Moffat said: Those panels are from 2012 it may mean getting an installer to lift a couple up to try and ascertain that info.🤦♂️ well, if you have a decent multimeter you could probably just measure as your existing system runs during the day, your existing inverter is presumably still in place, what are its specs on the solar input side? you may find your 12 panels are running 4S3P or 3S4P, if your existing inverter is the 145V max on the solar side, I guess, but the you can still figure out the app. V per panel and decide whether 12S or 6S2P would be the correct option...
November 14, 20232 yr Author 17 minutes ago, TaliaB said: Sorry @Moffat i did post about the 250w panels but there is quite a big Voc range from 23v to 37.7v Jinko. So would be best to measure your panels first before making a decision on connection configuration. I totally agree hence why I was also thinking of not ever mixing the Jinko and the old Solar panels on the same MPPT. Would love to put the current 12 x 250w panels to use rather lose them and have to buy 12 x 555w Jinko which would be an expensive undertaking.
November 14, 20232 yr Author 1 minute ago, Kalahari Meerkat said: well, if you have a decent multimeter you could probably just measure as your existing system runs during the day, your existing inverter is presumably still in place, what are its specs on the solar input side? you may find your 12 panels are running 4S3P or 3S4P, if your existing inverter is the 145V max on the solar side, I guess, but the you can still figure out the app. V per panel and decide whether 12S or 6S2P would be the correct option... Am currently running 12 x 250w panels on a 24v System and have to wire them so my max is about 102V, any higher they were overloading the system, being that it is small. I ideally don't have the cashflow to just totally dump them and run with Jinkos and I should think having 4 x 550w Jinko on each MPPT may be too small for the 8kVA inverter as a start. The battery may end up not receiving enough charge during cloudy days as well with such an initial start position.
November 14, 20232 yr Author 47 minutes ago, Kalahari Meerkat said: well, if you have a decent multimeter you could probably just measure as your existing system runs during the day, your existing inverter is presumably still in place, what are its specs on the solar input side? you may find your 12 panels are running 4S3P or 3S4P, if your existing inverter is the 145V max on the solar side, I guess, but the you can still figure out the app. V per panel and decide whether 12S or 6S2P would be the correct option... Those are the specs of my current inverter. I had to rewire my panels though because on some days my Vdc would be around 120Vdc so I'd get a PV overload warning on my inverter. Now it's set to maximum of about 102Vdc or thereabouts. Edited November 14, 20232 yr by Moffat
November 15, 20232 yr 9 hours ago, Moffat said: Those are the specs of my current inverter. I had to rewire my panels though because on some days my Vdc would be around 120Vdc so I'd get a PV overload warning on my inverter. Now it's set to maximum of about 102Vdc or thereabouts. Ok, I'm guessing you are running 3S4P with the 12 panels, you need to ideally confirm this, if that is the case and you get around 102V, then each panels seems to be around 34V and 12 in series (you'll have to re-wire again) would be 408V, which, I'd imagine should be fine and stay within limits for the new inverter. If, in fact its 4S3P, then the Voltage per panel would be 25.5V and 12 in series would be 306V, I think, which definitely is well within the limits by a huge margin for the new inverter. If the panels are 2S6P, I seriously doubt this, then each panel would be 51V, this seems way too high, so I can't think this is true, then 6S2P would be the setup for the new inverter, giving you 306V for 6 series panels. You will need to check what the current panel configuration is, I suspect 3S4P and 408V is likely the voltage that all 12 panels in series should then give you. Also assuming 34V per panel, if you want to be totally safe, then 6S2P should be 204V for the 6 series and that, again, would be totally fine for the new inverter.
November 15, 20232 yr Author I'm suspecting 3S4P with the current panels as max I get is 102V. Definitely rewiring will need to be done in respect of the new inverter and setup. I just didn't want to discard those 12 x 250w panels together with the older 3kW inverter, which would be a shame and loss, unless I donate them that whole old system to someone which would be: Inverter 12 x 250w panels 100Ah Battery; and Battery disconnect breakers as well...
November 15, 20232 yr 2 hours ago, Moffat said: I'm suspecting 3S4P with the current panels as max I get is 102V. Definitely rewiring will need to be done in respect of the new inverter and setup. I just didn't want to discard those 12 x 250w panels together with the older 3kW inverter, which would be a shame and loss, unless I donate them that whole old system to someone which would be: Inverter 12 x 250w panels 100Ah Battery; and Battery disconnect breakers as well... Based on your previous reply stating you get a PV over voltage error at 120V don't discard the possibility of having the panels wired as 4S3P. For 250W panels that is spot on the Vmp of 30V per panel as was normal for 250-275W panels.
November 15, 20232 yr Author 1 hour ago, Scorp007 said: Based on your previous reply stating you get a PV over voltage error at 120V don't discard the possibility of having the panels wired as 4S3P. For 250W panels that is spot on the Vmp of 30V per panel as was normal for 250-275W panels. Will do, thanks.
November 17, 20232 yr I have looked at a lot of panels The max possible configuration I was able to do is 22x 600w Canadian Solar panels (20x660W is also possible) It is 13200W but my inverter is set to 10400 I can only get there if my geyser is on and batteries are Charging at 160A(the fuses that I have is 160A still looking for 180A fuses NH2..) Edited November 17, 20232 yr by Yuri
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.