October 9, 20223 yr Good day all, Hope you guys can assist me. I have a question regarding the MPPT’s on this inverter. It’s specs say that it has 2+1 Strings. Namely PV-1 (this PV 1 has the +1 string) and PV-2(single string). Currently I have 24 x JA Solar 540w panels connected to all three the strings mentioned above. 8 panels per string. 3 x 8 = 24. This equals to roughly 12960w PV. So my question is this. Will PV-1 make use of all 16 panels connected to it via the 2 strings or how does it handle the two strings? What should I expect to get under good conditions? My panels are directly North facing and I live in Krugersdorp, Gauteng. I stress tested the system yesterday by turning on a few electrical appliances, toaster, microwave, Air fryer, pool pump was running as well. The load from the house was roughly 9Kw. The PV provided around max 6.8kw and the Grid the difference. This was during mid day. The angle of the roof I am not sure of. It’s a slate roof. I am expecting to get more out of the PV though. Or am I expecting too much? Any advice and opinions welcome.
October 10, 20223 yr What are the specs of the panels ? (Voltage , Amperage etc ) What voltage do you see on each string ? Voltage might not be high enough per each string to generate the power you expect.
October 10, 20223 yr My guess is that your load is imbalanced. That inverter can provide up to 6kW on a single phase, 12kW in total over 3 phases.
October 10, 20223 yr Author 59 minutes ago, Jaxone said: What are the specs of the panels ? (Voltage , Amperage etc ) What voltage do you see on each string ? Voltage might not be high enough per each string to generate the power you expect. Morning Jaxone, Panel specs: Voc = 49.6, Isc(A) 13.86, Efficiency 20.9%. PV-1 and PV-2 is on about 360V respectively at the moment. My thinking is that PV-1 Should be more on the Voltage? It has 16 panels between the 2 combined strings on PV-1. Edited October 10, 20223 yr by MorneS
October 10, 20223 yr Author 41 minutes ago, P1000 said: My guess is that your load is imbalanced. That inverter can provide up to 6kW on a single phase, 12kW in total over 3 phases. Morning P1000, I will have a look at the phases. They were "balanced" by an electrician. BUT the two Geysers are on one phase. I will have a relook at this.
October 10, 20223 yr 3 minutes ago, MorneS said: Morning P1000, I will have a look at the phases. They were "balanced" by an electrician. BUT the two Geysers are on one phase. I will have a relook at this. Well, it will depend on what you have switched on. It seems that most of what was on was in the kitchen. It would be strange to have different appliances in the kitchen on different phases (excluding oven/stove).
October 10, 20223 yr Author Here are screenshots from the mobile app. I will only be able to take physical pictures later when I get home. PV-1 as previously mentioned has the combined strings (16 panels). Pv-2 only has 1 string (8 panels).
October 10, 20223 yr Author 30 minutes ago, P1000 said: Well, it will depend on what you have switched on. It seems that most of what was on was in the kitchen. It would be strange to have different appliances in the kitchen on different phases (excluding oven/stove). You are correct. The kitchen is on its own phase. What I will check is if the phase that the kitchen is on is the same phase that the geysers are on.
October 10, 20223 yr Hi Morne, can you turn on all the load again and take screenshots again when the inverter starts using grid electricity?
October 10, 20223 yr Author 1 hour ago, mneeth said: Hi Morne, can you turn on all the load again and take screenshots again when the inverter starts using grid electricity? Hi! see attached below. So this is with both geyser operating at the moment. one is about 4kw and the other 2kw. They are both on the same phase. 4.87kw is provided by the panels and 3.73kw is provided by the grid.
October 12, 20223 yr Guess voltage is OK but what bothers me is your current on the PV1 is only 6A ! You should see much higher amperage on this string as you have 2 strings in parallel here. I run 18 x 390W Panels 2SP on MPPT1 and I have much higher current on PV1 around 18-19A at 6000W , and my panels can make Impp 11.54A / Isc 12.14A. Are you sure your strings are BOTH connected as they should. Try to disconnect them and connect them one at the time to see if there is any difference. Something not right as long as your Amps are same on MPPT1 and 2 and you have 2 parallel strings on MPPT1.
October 13, 20223 yr Author 11 hours ago, Jaxone said: Guess voltage is OK but what bothers me is your current on the PV1 is only 6A ! You should see much higher amperage on this string as you have 2 strings in parallel here. I run 18 x 390W Panels 2SP on MPPT1 and I have much higher current on PV1 around 18-19A at 6000W , and my panels can make Impp 11.54A / Isc 12.14A. Are you sure your strings are BOTH connected as they should. Try to disconnect them and connect them one at the time to see if there is any difference. Something not right as long as your Amps are same on MPPT1 and 2 and you have 2 parallel strings on MPPT1. Yeah you are right. PV1 and PV2 almost always have the same figures even though like you have mentioned, PV1 has two strings. I will get the guys to come and have a look again. Thank you for taking the time to comment Gents. Appreciate it.
October 18, 20223 yr Author On 2022/10/17 at 1:00 AM, Jaxone said: Solved ? Morning, No not yet. We are moving the strings for the current 8 panel 3 strings to 12 panels 2 strings on the 25th of October. Will give feedback once we have done this and see what.
October 18, 20223 yr Would have been very easy to just disconnect ONE of the two parallel strings and check for changes
October 18, 20223 yr Author 2 minutes ago, Jaxone said: Would have been very easy to just disconnect ONE of the two parallel strings and check for changes Would disconnecting one of the parallel strings make a difference? e.g. give higher amps and watts? When you say Parallel. Does this mean the inverter "chooses" which string to use based on available output? Can you elaborate on that please?
October 18, 20223 yr You say you have 3 strings , 2 connected to MPPT1 and 1 connected to MPPT2. If you disconnect one of the strings from MPPT1 and you see NO change , that means that string is not working If there is a decrease in AMPS on MPPT1 when you disconnect one string then both strings are working but maybe not optimal. If MPPT1 goes to 0 when you disconnect one string, that means THAT string is the only one that works. So to summarize and make it easy to understand : MPPT1 inputs are PARALLEL inputs. In Parallel connections , the Amps will double when you connect more parallel strings together and the Voltage will be the lowest voltage available on one OF THE strings. Try to google a bit serial and parallel solar panels , you will understand what I mean. You can also try to disconnect ALL the strings then connect ONE string at the time on ONE MPPT , no matter which , this way you can check if all strings work individually. Then connect one on MPPT1 input 1 , leave it run for a minute and then connect one more to MPPT1 Input 2 ... any changes ? This way you can test by elimination.
October 18, 20223 yr Author 23 minutes ago, Jaxone said: You say you have 3 strings , 2 connected to MPPT1 and 1 connected to MPPT2. If you disconnect one of the strings from MPPT1 and you see NO change , that means that string is not working If there is a decrease in AMPS on MPPT1 when you disconnect one string then both strings are working but maybe not optimal. If MPPT1 goes to 0 when you disconnect one string, that means THAT string is the only one that works. So to summarize and make it easy to understand : MPPT1 inputs are PARALLEL inputs. In Parallel connections , the Amps will double when you connect more parallel strings together and the Voltage will be the lowest voltage available on one OF THE strings. Try to google a bit serial and parallel solar panels , you will understand what I mean. You can also try to disconnect ALL the strings then connect ONE string at the time on ONE MPPT , no matter which , this way you can check if all strings work individually. Then connect one on MPPT1 input 1 , leave it run for a minute and then connect one more to MPPT1 Input 2 ... any changes ? This way you can test by elimination. Very detailed approach. Thank you for the reply. I will definitely do as you have said above. Try to do the fault finding. Will only be able to do it once the sun is out again. This week is a bit shy when it comes to proper sunlight.
October 26, 20223 yr Author So, we moved the 8 x 3 strings to 12x2 strings yesterday. The difference was astronomical. Achieved around 11 kw on solar load from the panels. Voltages are way better.
October 26, 20223 yr Author This photo shows a bit more info regarding load on the different inputs and outputs. Solar sell was on at the time. Turned off since. As far as I was told we are not allowed to sell to grid just yet.
October 26, 20223 yr 1 hour ago, MorneS said: This photo shows a bit more info regarding load on the different inputs and outputs. Solar sell was on at the time. Turned off since. As far as I was told we are not allowed to sell to grid just yet. That's MASSIVELY impressive
October 26, 20223 yr Glad you solved it. Before you moved strings , did you tried to see if one of the x8 strings was not performing as it should ? Edited October 26, 20223 yr by Jaxone
October 26, 20223 yr Author 12 minutes ago, Jaxone said: Glad you solved it. Before you moved strings , did you tried to see if one of the x8 strings was not performing as it should ? Yeah I am stoked as well. We didn’t no. My theory is that the PV-1 strings run either or. Kind of like if you wanted to have 1x string in an eastern direction and another string west/north. Then inverter “chooses” which to use? At the end of the day we decided to run 1 string per MPPT. i got what I was aiming for.
January 10, 20233 yr Just a quick question, your voltage of the 12 panels now are 595.2? Is that not very close to the upper limit?
January 11, 20233 yr 16 hours ago, Ross Muller said: Just a quick question, your voltage of the 12 panels now are 595.2? Is that not very close to the upper limit? The upper limit is 1kV, so I think he is quite safe.
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