3-phase system with 3× MultiPlus-II GX, powered from a single phase – configuration question
I am currently building a 3-phase system with:
3× MultiPlus-II GX
3× 16 kWh batteries
Configured as a 3-phase system
At the moment, only a single-phase mains supply is available
I have run into a few things that I have not quite been able to work out yet.
1. Phase assignment during configuration
When configuring the three MultiPlus units as a 3-phase system, as far as I understand it, the LED on the MultiPlus should start flashing to indicate which unit is being assigned to which phase. However, my MultiPlus-II GX has a small display and only one LED. I do not see this LED flashing as described in the instructions. As a result, I cannot tell which MultiPlus will ultimately be assigned to L1, L2 and L3.
Does anyone have experience with the MultiPlus-II GX and know how I can see or check which phase each unit has been assigned to in this situation?
2. Temporarily powering a 3-phase system with a single phase
My second question concerns the mains connection.
As I currently only have one phase available, I would like to power the 3-phase system from a single phase for the time being.
How should this be connected?
Should the mains supply only be connected to the MultiPlus configured as L1? Or should the AC inputs of all three MultiPlus units be connected in parallel to the same phase? Is a specific configuration setting also required in the MultiPlus/VE.Bus configuration for this? The intention is for the system to operate with a single-phase supply for now and then, once the 3-phase mains connection becomes available, to be connected as a fully functional 3-phase system.
Many thanks in advance for your experiences and advice!
There should only be one GX. Completely disconnect the other GXs in L2 and L3 nd connect all the inverters to each other via ve bus and the one GX.
Then use Victron connect to update the inverters and assign to phases
You can have a single phase supply to a three phase system, however you need to removed switched as a group off in the configurator. And only connect one inverter input (usually L1) to the supply.
Thks for your quick response and for taking the time to help me. I really appreciate your support and guidance.
I don’t completely understand your answer, because I think I have done exactly what you describe. Let me explain step by step how I built the system.
First, I connected one MultiPlus to the grid and to one battery. I switched it on and fully charged battery 1. Then I switched battery 1 off and charged battery 2, and afterwards battery 3.
After that, I connected all three 16 kWh batteries in parallel and connected them to the system. Up to this point, everything worked perfectly.
Then I connected the three MultiPlus units to each other via VE.Bus and switched on the other two MultiPlus units. I started VictronConnect, and it correctly detected all three MultiPlus units. One unit needed a firmware update, which was completed successfully.
I then proceeded with the three-phase configuration. My understanding is that during the configuration, the MultiPlus units should flash their LED one by one when a phase is assigned to them. However, I did not see the LEDs flashing. I therefore assigned the phases more or less randomly.
As far as I can tell, the configuration itself completed successfully. However, the system is now reporting that phases are missing and it will no longer charge.
So I have two questions:
How do I configure the system so that it understands that L2 and L3 are permanently not connected to the grid, and that the entire three-phase system can only be supplied/charged from one phase, L1?
During the configuration, how can I assign a specific phase to each MultiPlus if the LED does not flash to indicate which unit is being configured?
These MultiPlus units have a small display and only one LED, so I am wondering if the LED behaviour is different on this model compared with the units shown in the configuration instructions.
Could you please explain exactly which settings I need to change in the VE.Bus configuration/VictronConnect so that the system can operate as a three-phase system while only L1 is connected to the grid?
So, essentially, is 3× MultiPlus-II GX the wrong choice for a three-phase system? Does this mean I have to configure three ‘separate’ systems, with all three MultiPlus units connected to the same battery, but only one MultiPlus able to charge the battery?
You need one GX Multi and two standard Multi units.
Or one Cerbo GX/Ekrano and three standard Multi units.
There may only ever be one GX device in the system. In your case, that would mean that two GX modules would have to be disconnected.
If you decide to sell two GX Multis and replace them with standard Multis, the device ID or compatibility ID (for example, 1234_A or 4321_B) must be the same for all three devices.
The A or B designation becomes important if you need to connect additional MP units in parallel on the respective phase.
No. Suggest you read through the 3-phase setup manual and complete the free video training.
A 3-phase system is one, logical system. A system can have only one GX device.
Buying three GX systems is a waste of money, only one is needed, or none and an external GX such as a cerbo or ekrano.
Really suggest you contact an experienced supplier as this system is wandering into a larger scale for which we do not encourage design questions on the forum.
