paul99 Posted June 4, 2020 Share Posted June 4, 2020 Hi guys I have a goodwe 5048D-ES installed with 10 off canadian 400W solar panels on 1 string of the inverter and 4 x 2.4kw pylontech batteries I initially have just been running it in ups mode because of the load shedding we had last year The recommended setting did'nt work as the batteries were used up first for the load and then load shedding would kick in and the batteries were flat Now i am playing around with the economical mode to see if i can't get a better use of the batteries This won't work if we go back to load shedding next year I want to connect 4 or 5 more 410 watt panels on the other string as since the covid outbreak i am using much more power in the day and we are home 24/7 What i want to know is the following Can i have 2 unequal setups on the 2 strings ie 4000 watt on 1 string and only 1600 - 2000 watts on the other I don't have any more space on my house roof so i want to put the other panels on the garage roof which is 20m away from 1st panels Bit difficult to now change the wiring to the panels to balance them out with the 4 or 5 new ones The inverter spec says the max dc voltage is 580v and 6500w. Is this per string or is this the total for both mppt strings? At the moment i have peaked to about 430v early in the morning for about 1 minute ,but it usually runs at about 360-400v max with 11amps max in high summer The voltage over 400v is very rare It has gone over 11 amps a few times but only for a short time and hasnt tripped which i assume it will do if it does this for a prolonged time as the max on both mppt strings is 11 amps ea What worries me is that if i add 4 or 5 new solar panels the voltage will go over the 580v dc max if its the total volts for both mppt strings The spec sheet says you can run the 2 mppt strings in parallel What exactly does this mean? Will the amps on the 1 parallel string then go up to 22amps Can i parallel my 2 sets of pv panels (this will drop my voltage down and increase the amps) just before the inverter and feed that into both mppt strings by joining them in parallel also, or am i safe in plugging the new panels into the 2nd mppt string and leave the original panels as they are Your thoughts on this would be much appreciated Quote Link to comment Share on other sites More sharing options...
Wetkit Posted June 4, 2020 Share Posted June 4, 2020 Hi Paul99. Welcome to the forum. Yes, rather run 2 completely separate strings. Each string can be configured differently. Say you have your original string of 10 x 400W. Keep that one as is. Connect your new panels onto the 2nd string. Both strings would then operate independently. That is why you have 2 MPPT's Regarding your battery settings, please use the PV Master APP to configure your system correctly. You should be in General mode. Further you have DOD (on-grid) and (off-grid). Here you can now configure the unit to work great. Say 50% for on-grid discharge and 89% for off-grid. Now under normal conditions your batteries will only discharge to 50% and then you still have 39% left for Load Shedding :) francois 1 Quote Link to comment Share on other sites More sharing options...
paul99 Posted June 4, 2020 Author Share Posted June 4, 2020 Hi wetkit i tried the general mode previously set more or less as you said At a stage we had load shedding stage 5 with grid on for 4 hrs and off for 2hrs the problem comes in the evenings when cooking tv etc draws the batteries dead within 5-6 hrs the problem with this inverter is that it doesnt want to charge the batteries from the grid if it can help it in general mode in economical mode you can set when you want it to discharge and charge, although i have found this does'nt exactly work as it should today i set it to group1 charge from 23h00-23h59 group2 discharge from 00h00 - 06h00 group3 discharge 21h00 - 22h59 group4 charge 17h30 - 20h59 At 16h10 it started discharging the battery till 16h20 then i saw it and stopped it by making group4 charge from 16h00 will see tomorrow what it does i found it would wait 5-6 hrs sometimes for panels to come on before it would start charging in general mode as soon as this happened (about 7am) it would share the charging with the grid if the panels did'nt output enough energy also even though the pylon batteries said it could charge at 100 amps it would never do this and only charge at 10-20 amps which could take a few hours to get to 100% so by the time load shedding kicked in again with the batteries being depleted thru the night they would never catch up the charge in the 4 hours without load shedding except in the daytime if there was full sunshine at night i would run out of batt power at about 3-4am especially if we had a cloudy day so i went over to ups mode and the problem was solved batteries only get used when grid fails this will also prolong the life of the batteries as they almost never cycle, but i don't know if this is the best cost saving mode i must mention that my meter runs backwards when i pump power back to grid and normally i pump more or less back what i use over last year i am 500 kwh up from where i started a year ago but with the virus which can have me locked up till next year as my wife is quite sickly, the situation is quite a bit different and winter is just beginning i must say i havent tried general mode again since the firmware upgrade a few weeks ago so maybe the charging issue has been fixed cant see it making any difference what mode i use as long as the batteries are 100% SOC there when grid fails But getting back to my problem you say leave the panels on string1 as is then plug the new ones into string 2 well the 10 x 400w panels on string1 are rated at 48v ea max so that's 480 volts and the 5 panels on string 2 will be rated at 50v ea that's say 250v now it says in the specs that the max dc voltage is 580v 480+250=730v which is over the max or is the 580 v per mppt string i am safe in the watts dept 4000+2000 = 6000w and max watts is 6500w input would be appreciated many thanks Quote Link to comment Share on other sites More sharing options...
Saint Posted June 4, 2020 Share Posted June 4, 2020 hi Paul, Quite the novice myself, however i will try and answer the things i think i am fairly sure about... i have a similar setup.... one problem you are facing during general mode is because it seems or sounds like you are not grid limiting, and is indeed feeding back into the grid, that way it will not charge the batteries first (in essence you are using the grid as a battery transferring extra generated power back to the grid). You need to limit you exporting wattage via the pv master app to 0 watt. That way any extra power not used by your instantaneous load will be charging your batteries, now it goes into the grid, change this setting and any etra power will go straight to your batteries the moment your pv start generating,(grid backfeeding is also depending on where you are actually illegal, except for capetown and i think PE last time i checked). Luckily with the goodwe it is not dangerous since it will isolate itself if the grid goes off preventing an accidental electrocution of a guy working on the municipal lines.... in theory... If you fix those settings you will find the general mode works great. I have a similar setup to yours and regularly or daily charge my batteries at a rate around 3000-4000watt or there about.... you can go to a maximum of 100 amps charging current granted your batteries can handle that charging rate.... for the mppt's, that is the dc rated voltage per mppt string, so you can safely add the additional panels on the second string, should be no problem, you can add even slightly more since you are still under the theoritical maximum and there will be additional losses due to cables and panel angles etc etc.... hope this helps or makes some sense... Quote Link to comment Share on other sites More sharing options...
Wetkit Posted June 5, 2020 Share Posted June 5, 2020 As Saint mentioned, you have to enable the Export Power Limit and set the limit to ZERO. If your batteries is not enough to power you through multiple load sheddings, you either have to add more units, or limit the consumption during loadshedding, or increase the DOD for on-grid. In general mode the unit will not charge from mains, as that would be wasting money. Regarding the MPPT, 580V is the max for each string, not the total voltage, so you should be fine there. Quote Link to comment Share on other sites More sharing options...
FixAMess Posted June 23, 2020 Share Posted June 23, 2020 Keep the following in mind....(From Goodwe) The recommended maximum is 6500w total as you will be limited to around 3200w per MPPT with a total around 5200w AC power should the temperature be in range. Please keep in mind that 550v is the maximum working voltage above that 580V is the safety factor. We recommend a voltage around 360v per MPPT for optimal performance -------------------------------------------------------------------------------------------------------------------------- You should reduce your 1st string to deliver a maximum of 3200W (so install a max of 3500W panels , assuming 90% efficiency), if you install more, even within the Voltage limit, the MPPT can support a max generated of 3200 Watts. For the 2nd string, just use 6mm cable, it must also be in steel conduit, not PVC. Quote Link to comment Share on other sites More sharing options...
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