Growatt SPF5000es SUB mode in parallel,host inverter uses solar but slave inverter runs on AC bypass

[Camdelta2]

Hello fellow diyers,

Looking to see if anyone else has the same issue as me or possibly a solution,

TL,DR: Host inverter uses solar to power load and charge battery in SUB while slave inverter runs on AC bypass

I recently built this system myself with 2x growatt spf5000es inverters both connected to a 5,1kwh Lifetide lithium battery communicating through rs485(South African company) as well as 10x 555w jinko panels in 2 strings with 5 panels each. The system works fantastic in SOL mode as well as SBU however when I change it to SUB(the mode I would like to use) the host inverter uses solar first and then grid while the slave inverter completely disregards the solar and runs on AC bypass. The load is correctly split between the two inverters which results in the one string doing nothing and unnecessary utility power being used. A bit of a head scratcher as if I put the inverters in SOL mode they both use solar from their strings correctly. Looking for any suggestions.

Both inverters had the latest firmware installed when bought and both have the newer revision of the communication board.

 

[jbean22SouthAfrica]

I am currently experiencing the same situation. When I have my two units running in SUB mode, the one unit pulls proper draw. However I noticied when disconnectin one string the pull actually increases while in sub mode for the one string attached. So for example if the system is in SUB mode and both string attached, the system that is drawing watts will display 1000W. When I disconnect the string that is not displaying pull in the app, the draw on tyhe other system(working one) goes up to 2000W for example.

Now when reading your post I went home and switched to SOL mode and the system shows the correct Wattage for each unit as I have 7 and 6 strings respecatbly and the system is showing 960W and 1150W which would be correct. Again now this is whats confusing me. My load is on 2600W and the grid is drawing 2600W, the battery is charging at 900W odd, each panel pulling the mentioned wattage but nothing is going towards helping the load and reduce electricity bill. Both arrays of panles seem to be charging the battery only and nothing is reducing grid load?

 

[Camdelta2]

I am currently experiencing the same situation. When I have my two units running in SUB mode, the one unit pulls proper draw. However I noticied when disconnectin one string the pull actually increases while in sub mode for the one string attached. So for example if the system is in SUB mode and both string attached, the system that is drawing watts will display 1000W. When I disconnect the string that is not displaying pull in the app, the draw on tyhe other system(working one) goes up to 2000W for example.

Now when reading your post I went home and switched to SOL mode and the system shows the correct Wattage for each unit as I have 7 and 6 strings respecatbly and the system is showing 960W and 1150W which would be correct. Again now this is whats confusing me. My load is on 2600W and the grid is drawing 2600W, the battery is charging at 900W odd, each panel pulling the mentioned wattage but nothing is going towards helping the load and reduce electricity bill. Both arrays of panles seem to be charging the battery only and nothing is reducing grid load?

Hi JBean, i seemed to have somewhat rectified the issue that i was getting, it seems to be anissue with having 2 inverters connected to one battery through BMS, not too sure on the specifics but if i changed my inverters to both use battery setting us2(No BMS Communication) and manually set the charge voltage and current the inverters pull correctly from solar and blend correctly with grid when they are in SUB mode. Let me know what components you have in your system and maybe i can try and help you