Grid meter, AC loads before and after Multiplus, shore current limit issue

DIY
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1

Hello,

Just installed the VM-3P75CT (set for one phase only, readings on it are as expected) as a grid meter for the small Victron system in my trailer.

Having an issue where the Multiplus icon on the Cerbo S-GX (V3.80) Venus GUI v2 shows a load (that is wired to the ACin/ non-critical side) on it’s bar graph, it also goes into invert mode like it’s trying to prevent a shore current overload if I have a high enough non-critical load.

(That is the bigger issue, going into inverter mode)

MultiPlus 12/1200/50-16 120V (the plastic one)

30 amp 120v mains coming in, feeds breaker panel with some AC loads (non-critical) +15 amp circuit feeding Multiplus for the critical circuit.

Now I understand what is happening, the 15 amp (16 max on this model) shore current limit as set on the multiplus is being assumed for the entire system.

Looking at the details on the Multiplus it’s readings show that it knows the load is not running through it.

It seems like turning on the option in Venus OS for AC loads before and after the multiplus should give you an option to specify what your shore current limit is different than the one on the Multiplus, or something along those lines. Seeing as having loads before the inverter would imply to me that there’s likely a breaker panel there.

I did some searching on the forums and have looked through I think all of the settings, I’m hoping it’s something silly I’m missing.

If there’s a workaround using node-red I’m open to that as well, but was really hoping sticking with all first party devices things would “just work”.

Thank you all for any advice

(Sorry for the long post, tried to make sure all the details were there)

(Tagged this as beginner since my day job isn’t installing Victron, but I’ve worked on or installed multiple small off-grid and mobile systems of mixed brands)

2

Energy meter is connected over VE.Can, forgot to mention that if it makes a difference.

Thought about one way I might be able to work around this is set the grid meter as generator and was hoping it would just show up on the AC source side of the GUI and be monitored, but it doesn’t, I assume because this multiplus only has AC one input so the Cerbo has no clue what to do with the data.

Then I tried setting the energy meter to PV inverter and that actually is a kind of silly but (almost) livable work around. I now have proper readings for “shore power” which is just the critical circuit and “solar” which is my total draw from shore. Multiplus works properly at least, doesn’t go into inverter mode with a non-critical load.

Kind of silly and rather annoying but I could at least live with that if it really is my only option, works fine in the local GUI,

BUT on vrm it ends up kind of breaking things as vrm calculates the solar with shore power so it shows my shore power as a negative number…

I’ll leave it this way for now as I mostly use the local GUI, but would be nice to get this solved the proper way.

EDIT: I changed the energy meter role to be an EVCS, that way at least all of the metering and VRM information etc is showing loads instead of solar. Need to double check if the Multiplus still behaves properly when I turn a bigger non-critical load on.