I would like the have some advice on the “L2 and L3 not in phase” issue that I’m encountering with my Victrons.
My setup is as follows:
three Victron multiplus ii 6k5 converters, in a three phase set up
A Cerbo GX to control
Two Victron distributors to connect the DC
3 Seplos Mason 280 battery boxes, in total 48 kWh storage
Initially I connected the Victron Multiplusses with DC only. I was able to connect and set them up for three phases. When that all worked, I connected the AC-in. The first phase (L1) was able to synch. However L2 and L3 gave the message not synching. By measuring the source, it turned out that indeed L2 and L3 were switched. We swapped that, and reset the batteries (fully disconnect) and decommissioned the AC-in. By starting up again, the message kept popping up that L2 and L3 are not in synch. See pictures.
Now I have the following questions where I would like to have your responses:
Do I need to redo the full VE.Bus 3-phase assignment?
If so, what is the correct procedure — do I need to go back to DC-only mode and run the assignment wizard again?
Is there a reset or re-sync option for reassignment?
Are the MPs switched on and working in island operation? Since the VE.Bus monitor does not show any output voltage, which should be present with or without mains
Unfortunately I get the error in both scenarios. I think that is the issue. After disconnecting from the grid, the error remains “in memory”. So it seems that there is not refresh (or I cannot find the forced refresh function).
What I did is first configure the MP’s and setup with DC only. The next step was to commission AC-IN. Then this error with Phase 2 and 3 popped up. Indeed L2 and L3 were switched, which was corrected. The system and batteries were brought down again. Then DC was connected and AC-IN. The error is still there. The last step of also switching the AC-OUT line to commissioned, was not yet performed.
I personally do this, DC first, then communication/firmware/settings, then ACout and last step is ACin.
I just find it odd that none of your MPs show output voltage. Since thats independent of the mains. I would check if thats true, and if it is, looking into why. If theres no output voltage then theres nothing to synchronize to, so “not in phase” is understandable.
On your schematic, are you sure that the order of things is correct? Your mains fuses are 25A, the output of the MPs is 50A and the house is 40A? I would not be allowed to build a system like that, since fuse values have to be a regression, so mains 50A, MP output 40A, house 25A. To ensure that the closest-to-fault fuse trips and not some further away.
That was my number one suspicion. A dual trace oscilloscope can find out, but that’s not in many tool kits. Some portable meters check this, also not cheap.
You cant assume that the grid has the correct phase rotation going by the colour coding.
Thank for your responses! It works now. Indeed you need to set up the Victrons in standalone mode first. Then you can select set up three phase multi set up. On that moment you are asked again to assign the Victrons to each phase. Now it works!
