Hi there, the specific question is which components are strictly needed to work with load balancing limits in the EV charging station (in my case: 32 Amps in a 3 phase system) defined by the local grid net provider and primary and secondary fuses.
So given that a normal connection in Austria has 3 phases with 35 Amps each, but there are also multiple other devices consuming power in a household besides the EV charging station, the 35 Amps limit (32 Amps) shall not be surpassed.
Do I just need a compatible smart meter (which one) or do I need the Cerbo GX station as well to let the EV charging station dynamically adapt to the available power.
I second the question. I’m currently on the market for installing an EV Charging Station (possibly two) at home but it’s kind of unclear what’s needed for DLM and have the charging stations back off (i.e. other loads in the house take priority) and prevent the main breaker from tripping.
Currently Victron EV Charging stations do not have dynamic load balancing feature available.
There is a function which prevents an overload, but that is not to be misunderstood as a load balancing feature.
You can use node red to program something yourself and there are some DIY’ers providing already running scripts.
You would be needing a Cerbo GX ( which hosts Node Red but also gives you VRM ), a Victron Energy Meter and a Victron EV Charging Station.
Hope that helps a bit more but I could also raise more questions ;-).
I want to raise this issue / upvote it! Active load balancing for the charging stations is an absolute must have in my opinion!
I’ll be installing a victron PV/battery system in our new home and would like to use the EV charging station as well (two of them) to charge our cars but it is essential that our 3x25A main grid connection does not get overloaded by them.
Thanks for your reply and it’s great that overload protection is already implemented!
What I read in the manual, is that this will still be a bit of a ‘rough’ process where, on overload, the EVCS will reduce charging to minimum and then either continue charging on it’s lowest setting or when the overload persists stop, start again, cause a new overload condition, repeat this loop a couple of times and only then will it gradually reduce the charging current to stay within the limits? Do I understand this correctly?
I can imagine that, especially with two chargers connected, and depending on the cars that are connected, possibly one EVCS only charging on L1, the other on all phases, this might lead to a lot of starts and stops and constantly varying electrical loads on the system which is not desirable.
It depends on the load size and how much power we have available from the grid/inverters
If you have 16A that you want to share with home consumption and 2 EVs, then yes, it’s going to stop the charging. In cases like that, you should limit the maximum current to something safe. Especially if there are big loads in the house like heat pumps, compressors etc.
Still, there are lots of extra setting that can help you even in case like this, you just need to fine-tune it a bit.
And if that’s not enough, you can control it externally through node red or something like that, and create your own special algorithm.
In our current house we have a zappi EV charger with load balancing. What this one is doing, is simple measuring the load and when it sees, lets say, a 5 amp overload, it will reduce it’s consumption by 5 amps. Or put the other way around: it only takes up the ‘headroom’ that’s left after other house loads that cannot load balance. I would imagine that this concept should not be very hard to implement through node-red?
Ideally I would want to be able to set an order of importance for all devices. For instance that charging the cars takes priority over charging the 48V system. I cannot test this at the moment though, since I don’t have a victron EVCS yet…
Would you be able to share some insight with regard to how Victron proposes to approach load balancing?
We are considering the overload to be a dangerous event. The whole flow is like this:
the system consumes let’s say 5A more than it should, the meter measures that value, the EVCS receives that info, calculates the new charging power and communicates with the vehicle to lower the consumption, then the vehicle reacts. The entire process takes 1–3 seconds, sometimes even more, depending on the communication infrastructure, meter type etc.
We decide to be more cautions and better to reduce to min. or stop charging, than trip the main breaker or cause inverter power down because of prolong overload. And that’s because we are also doing the rest of power electronics for that system, not only charging stations.
I heard lost of stories with charging stations causing the issues above.
I can imagine that this is not trivial, given the number of possible combinations with all components in the Victron ecosystem!
I have the new CANbus energy meter VM 3P75CT, so that should at least give an almost realtime measurement on the grid connection. With my zappi charger, that seems to work more or less like you are planning to implement things, I never had a tripped main fuse since this is a type C fuse that can take a quite some overload for a bit longer…
