Willa Kotze Posted June 16, 2019 Share Posted June 16, 2019 (edited) Hi We have 2 10kW 3Phase Mecer/Infisolar Hybrid inverters connected in parallel. Why does the Master constantly discharging the batteries and the Slave charges the batteries? It is ongoing throughout the day, non-stop. The other question: Why does the Inverters use so much energy from the Grid? If we disconnect the Grid it runs smoothly on the PV and the batteries but as soon as we connect the Grid it takes energy from it? Edited June 16, 2019 by Willa Kotze Forgot to insert a word in the sentense Quote Link to comment Share on other sites More sharing options...
Jaco De Jongh Posted June 16, 2019 Share Posted June 16, 2019 1 hour ago, Willa Kotze said: Hi Welcome Willa 1 hour ago, Willa Kotze said: Why does the Inverters use so much energy from the Grid? How much is it using from the grid? 1 hour ago, Willa Kotze said: Why does the Master constantly discharging the batteries and the Slave charges the batteries? This is a bit strange and makes me think it might be a setting issue, Different modes or priority's selected on the inverters. For interest sake, do you share a battery bank or does each inverter have its own bank? Quote Link to comment Share on other sites More sharing options...
Youda Posted June 16, 2019 Share Posted June 16, 2019 (edited) 7 hours ago, Willa Kotze said: Why does the Master constantly discharging the batteries and the Slave charges the batteries? It is ongoing throughout the day, non-stop. This is normal for master-slave setup of InfiniSolar. These two inverters should share a common battery bank and once the battery is full and there's no heavy AC load, then only one inverter is drawing energy from PV modules to run the loads. The second inverter is just pulling the energy from that common 48V DC bus, therefore it looks like it's discharging the battery. But in fact, the two inverters are just sending energy to each other via that DC bus. Once you put a huge load on the system, then both inverters will start to draw energy from the PV. After running a huge load for some time and then disconnecting it, you will see that both inverters will start recharging the battery from all the available PV. 7 hours ago, Willa Kotze said: Why does the Inverters use so much energy from the Grid? If we disconnect the Grid it runs smoothly on the PV and the batteries but as soon as we connect the Grid it takes energy from it? This depends on the operational mode. The worst mode (causing high grid consumption) is grid-tie with backup and disabled grid feed-in. In this mode, the inverter is pulling more than 150W from the grid, even if the sun is shining and the batteries are full. This 150W pull is there to create a sort of "bumper" - it minimizes spikes of the excess energy that would normally go to the grid. If you want to minimize this, there's a calibration field available for every phase. But it will increase grid feed-in, so the best solution is to either have the inverter in off-grid mode or have the grid feed-in approval from the municipality (and earn a few bucks on sold electricity too). Edited June 16, 2019 by Youda Quote Link to comment Share on other sites More sharing options...
Willa Kotze Posted June 16, 2019 Author Share Posted June 16, 2019 Hi It uses about 8kWh at night (18:00 - 06:00) It is a off-Grid set-up with priority when PV not available: Batteries-Grid We are using SolarPower to do the set-up. The battery bank are not too small because we still have 50% available and the inverters share a battery bank. The charging/discharging make sense now, thank you Youda. Regards Quote Link to comment Share on other sites More sharing options...
Youda Posted June 16, 2019 Share Posted June 16, 2019 (edited) 8 kWh per night sounds like a consumption for a whole house. Are you really sure that this (8kWh/12hrs) is the idle consumption of the two inverters? In the off-grid mode, the idle consumption from the grid should be like 10W total (in this mode, grid is used just for sync). The best off-grid mode is called "Off-Grid III". Try this one and all the idle consumption should be satisfied from the batteries. Edited June 16, 2019 by Youda Quote Link to comment Share on other sites More sharing options...
Willa Kotze Posted June 17, 2019 Author Share Posted June 17, 2019 I am absolutely sure, we have a pre-paid meter installed, so we can actually see the units that it uses. When we had only one inverter it was about 10W in total but the moment we added the second inverter it went crazy. It is something that we don't understand and we are having a hard time to find somebody to explain it to us. Maybe we did something wrong with the settings. We are using the usb to set each setting separately, we still need to buy the bus card to sync the 2 inverters. At the moment we disconnected the Grid totally and are only going on solar but we would prefer to add the grid since we do have machinery that need the extra help from the grid to start. Quote Link to comment Share on other sites More sharing options...
Youda Posted June 17, 2019 Share Posted June 17, 2019 Okay, I see... Having the identical settings on both inverters running in parallel is crucial. Of course, you need to connect both units with current sharing cables, as well as comm cables. Extra card for the intelligent slot is not really needed for the parallel setup. The best way to set inverters in parallel is to use the software Solar Power Pro, connect to the master inverter via serial cable and whenever changing any setting, be sure to check the SYNC checkbox next to it. This ensures that the slave inverter will be set to the same value. This is how it should look - note the SYNC checkboxes: In the above example, I'm using a connection via SNMP Cards, but it works via serial cable too. Quote Link to comment Share on other sites More sharing options...
Willa Kotze Posted June 17, 2019 Author Share Posted June 17, 2019 Thank you I will go and have a look. I am not sure if we are connecting with current sharing cables as well as comm cables. Maybe that is our problem, the fact that we use SolarPower and not SolarPower Pro. I will get back to you about that one. Thank you in advance. Regards Quote Link to comment Share on other sites More sharing options...
Willa Kotze Posted June 17, 2019 Author Share Posted June 17, 2019 Hi I tried to connect Solar Power Pro to my inverters but it doesn't want to read it. I used the USB port, I will try the serial cable tomorrow. We are using the Rasberry PI as an ICC but we heard that it is not compatible with the 10kW 3Phase inverter yet. Can I rely on it for an estimate on the monitoring system or is it completely wrong? Regards Quote Link to comment Share on other sites More sharing options...
Willa Kotze Posted June 19, 2019 Author Share Posted June 19, 2019 Hi guys Okay, so I have tried to connect with Solar Power Pro but no success. I still have the same problem: The inverter is taking energy from the Grid, even though the PV and the batteries are more than capable to support the load that we use. Regards Quote Link to comment Share on other sites More sharing options...
Nicholas Posted July 22, 2019 Share Posted July 22, 2019 ICC is compatible with the 10kW InfiniSolar inverter. What mode are you running the inverters in? Is the PV equally distributed across both inverters? Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.