Hi, I’ve got a single phase connection in Australia, with 3 Multiplus-II 3000va in parallel and an ET112 energy meter.
After my electrican has come around and connected all the loads to the AC-Out, when we are pulling a large amount of power (i.e. more than 1kw) we’re noticing that our grid usage seems to increase to around 300-500w (as shown below).
Is this expected behaviour, or have we done something wrong here? If we reduce our power usage to 600-800w then we see the grid use normalise to around 70-120w which is what I would have expected it to be.
If it’s of any help, here’s what our Grid Setpoint is configured to:
How does the PV connect to the system, i guess its AC coupled? Does it connect on the ACin side of the MPs? The ET112 is measuring the grid? If yes then you would need to switch “grid metering” to external meter instead
Hi chrigu, yes confirming the PV is on the AC-in side of the multiplus (grid side), with the ET112 measuring the grid. I have attempted to swap between external meter (ET112) and the internal measuring. I’m wondering if my electrican left the neutral connected to the ac-out of the Multiplus installation, rather than the grid ac-in side by accident. - Not sure whether that could be a factor.
There needs to be a neutral on both ACin and ACout. ACin neutral comes from the grid, ACout neutral goes to the load.
There is some speciality in autralia that requires the ACin and ACout neutrals to be bridged together, in conjunction with the external neutral path gridcode. So you could use only one conductor, but you still need to use both terminals on the MP
So swapping it has made a slight improvement and definitely when using under 1kw the grid usage is approx 70w or so with my current settings.
If I load up the ac out of the inverters by charging an ev for example then the issues seem to be present still.
Apologies for the confusion regarding the neutral. At the switchboard both the ac in and ac out neutrals are both separated however I think in the electrician’s confusion he may have left the 2x et112 energy meters using the neutral from the ac out side instead of the ac in (as their active cables are on the ac in(grid) side.
if you only have 1 MEN link which is what you should have in Australia strictly speaking the the neutral between AC IN and AC OUT must be bridged together.
Our MEN is in the main switchboard (where the grid supply comes into the property) (i.e. only a single one for the installation). The neutral’s for the loads have been separated and soley also on the ac-out for the installation.
To my understanding this should be correct, because the victron will use the grid present/passthrough men when that’s available and if it’s not, should create it’s own when it’s offgrid, etc.
You need to follow the manual and bridge the AC IN1 and AC OUT1. It’s explicitly mentioned for AU & NZ where there is only 1 MEN link. The grid code you have selected is not correct. You need (with N-bypass)
Thanks powersquad, everything I’ve found so far online has suggested that the neutrals should have been kept separate, however I’ll do some more research and if so join the neutrals together.
Given I’ve got 3 inverters in parallel, do you think this is best served by completing the join in the switch board?
Correct, the join between AC IN and AC OUT1 port needs to happen at switchboard regardless of whether you got 1 inverter or 3 in parallel. From the AC OUT on switchboard, you then run the AC OUT coupling cable to each of your inverter’s AC OUT port in parallel on the same phase of course. For different phases, you will need different AC OUT coupling done at switchboard fyi.
Legend, thanks powersquad. Yes the area I’m in uses Australia A. Will have a look at this over the weekend and get it swapped over. Can’t thank you enough for your help.
hey powersquad. Not sure if you have any other ideas, however I’ve had my electrican around this afternoon and we’ve installed joined the neutral from the AC-Out to grid neutral and changed the victron grid mode to (with N-bypass). It’s definitely helped fix the random RCD tripping, but alas, I’ve still got a surprisingly high grid usage as shown below:
Possibly the only relevant thing is that I’ve got allow feed-in unticked as we don’t want the ESS system to feed into the grid (as only our grid-tied solar pv systems are approved for that), but would have thought that surely it shouldn’t be this conservative.
