If you asked me yesterday if a system with only one Multi RS connected to one phase of a three phase grid: does this configuration support grid in-line mode and self consumption from battery on all loads (at AC-in and AC-out side), I definitely answered “yes”. But today I’m not that sure anymore because of the following:
While playing with VictronConnect demo libary, using Multi RS Smart, I saw in the dropdown box >settings >system >system configuration the following text at the “single phase” option: “Only inverter parallel mode is supported”.
So for me, and probably others, I want to make very sure what modes the Multi RS does support. And I ask you to confirm or correct the following configurations:
Multi RS (solar) single unit connected to single phase grid
Multi RS (solar) single unit connected to a single phase on a three phase grid
Multi RS (solar) two units (one on phase 1, one on phase 2) connected on three phase grid
Multi RS (solar) three units on three phase grid (every unit connected to another phase)
Does all above configurations support grid-parallel, grid in-line and a combination of both, and do they all support self consumption from battery (and in case of one or two units on three phase grid does it compensate all phases?)
Of course, compensating loads at the AC-in side needs a power meter like the VM-3P75CT.
Another confusion (or maybe the answer on the above): what is the difference between “standalone” and “single phase” mode at >settings >system >system configuration ?
I had to temporarily do this while a unit was out of service. The system could not start up with only 2 inverters, even though continue with missing phase was selected and number of inverters was adjusted. Thread here: Continue with Missing Phase is Missing the Point
The way I did it was to set both up in standalone mode. Both followed the grid and stayed 120° apart. In the event of a grid failure, they would not stay synchronised and will inevitably drift. This was acceptable to me, as the neutral cable was sufficient and protected for the full load of 2x inverters.
I only ran like this for week while the RMA was in progress, until I reverted to full 3 phase operation.
One thing is still not clear to me, and can’t find it in the documentation: the difference between “standalone” and “single phase”.
I do understand from your answer to use “standalone” to achieve grid parallel in combination with grid in-line (with one unit on single or three phase grid). So that is clear.
But I’m curious what “single phase” is different from “standalone” and when is usecase this option used?
@deon.korb thanks for your reaction (read your linked thread).
Because in the future I might need two units (certainly not three) because one unit is a pinch to small. So I will ask @lxonline for advise: is there a way to have two units (MRS) each coupled to another phase of a three phase grid connection, and have ESS (selfconsumption) and UPS function? Is the suggestion of Deon (in the linked thread) the correct way to set both units to “standalone” and in different instances (I don’t care if the phases no relationship, we don’t have “real 3 phase equipment”). And can this be accomplished / managed with one Cerbo GX?
Standalone is a single unit (so obviously single phase). I think the distinction is that the unit does not have to synchronise to anything, and also doesn’t have to communicate to any other unit.
“Single phase” is intended for multiple units (potentially fault tolerant) operating in parallel, all synched to a single phase. Parallel does have its limitations for the time being (no AC In).
My 2 units on different phases workaround was an abuse of standalone, hence me not recommending it for long term use.