roboza

Thank you for your input. I 100% agree with you on your interpretation however my inverter does not have the SUB option. Only the other 3 options.

Hi , First post here. I have recently had a system installed at my house. Nothing fancy but something to allow me to work when we have no power. So far the system does what I need but I have a question on configuration. I have 2 major options when configuration the inverter. Output source priority selection 1. SbU. Solar energy provides power to the loads as first priority. Solar and battery will provide power to the load. When the batter drops below a configured voltage it will switch to grid. 2. Uti. Solar use used when the grid is not available. Grid charges the battery. Using the SbU mode: The problem with this and I found it out the other day. During the day it worked perfectly. We hit 7pm Sun was gone and the battery started to get used. At 8am load shedding hit and by that stage the battery was around 20%. The utility would only charge once the voltage was low enough on the batteries. What happened though was the battery hit 10% during load shedding and then the utility was not able to charge the batteries and we had to wait for load shedding to finish. Using Uti mode: This works fine. I have configured the inverter to charge the batteries with solar however, if there is excess solar the inverter still uses utility to power the load. The only time solar is used is when there is no Utility power available. I did some tests and set the voltage on the battery in the inverter to not go below 26.5V so the SbU mode works and then if the battery goes below 26.5V Utility power kicks in to charge it and serve the current load. During the day the battery and load are both served from the Solar power. Does anyone know of a better way if possible to do this. I am using a MUST Inverter PV1800 3kw