I have the same problem.
Only solution for now is using ac-out2 for powering the car charger and solar panels who needs to go off when grid fails.
If you put solar on ac-in and in the summer there is max. Delivery back in the grid (16A) + the inverter decides to feed in the grid with max capacity the main breaker trips also.
So it is not only a draw from grid problem but also an upcoming feed-in to the grid issue.
For people with reachable main breakers as a switch its not a real problem but in my case i have the old melting fuses so i need to call the network supplier (Stedin) who will charge me €650 per visit.
Why is this post split in 2 different ones? The problem is exactly the same as the first post starter mentioned… !
The system is not peak shaving on the grid meter.
For me now it’s a hypothetical problem because i have put everything on ac-out
I have 3 phase mp2 -48-5000 with 20 kWh pylontech
Phase 2 and phase 3 has about 2500 wp per phase and only normal loads like washer and dryer and some air-conditioning
On phase 1 are the heaviest loads, 16A car charger, heat pump, 150L boiler and also the most solar yield. In total on phase 1 is 5670 wp solar. 3000 on AC-out1 and 2670 wp on AC-out2 (switches of in case of grid failure)
So theoretically i can feed in phase 1, 25A of solar and 17A of inverter power when the sun is fully shining and the inverter (for any unknown reason) is also feeding in the grid.
With my 3x25A main fuses (type C i guess) it is waiting to be blown when solar is on AC-OUT.
And then knowing i have bought the whole Victron system (€8700,-) for peak shaving purposes i am fairly disappointed the system is not protected by the VR3p75CT grid meter but everything needs to go through the inverter.
The result is also that my car is now draining the battery when the dynamic price are low because “battery used for critical loads only” also applies to AC-out2.
This can be affected by settings and set up. So first that needs to be explored.
Since your system is not the same as the other poster it is now a unique thread.
No it is not a setup or settings issue. The problem is in the victron approach.
I have tried all possible settings several times.
I have tried several posts on this forum about this same subject. I even emailed Harold Halewijn, a famous installer who put all his experience on YouTube and even he said this is a victron problem since venus os 3.30
The only important thing for a grid meter is to keep the import and export values as set in the system.
It should be fairly simple.
It you say no more in or out than 25A and you have a grid meter than thats the limit.
No exceptions.
If you have no victron system, just a power line with 10A breaker.
If the boiler is on (6A) and the washer is pulling 8A during heating the main breaker trips.
If you have solar coming in on the same line the load in the breaker stays within it’s limit.
Peak shaving is what controls this, the system should also supply from battery above the input limit, provided the battery is above min soc, or there is solar.
This requires ESS to be operational and loads to be on AC OUT only, not grid parallel.
And that’s the problem because if everything is on AC - out your car charger is draining the battery even if the dynamic power prices are low at that moment. Supply from battery (only critical loads) does not do what is said because loads on AC-OUT2 are not critical loads (they are disconnected when grid fails) but still be draining from battery!
AC2 can be forced on, there are assistants for that.
AC PV introduces another variable into the equation.
The system also has ramp times, so load can fluctuate, especially as larger ones are switched in/out.
Victron EV chargers are meant to have intelligence to restrict what they draw based on system state to prevent batteries being drained.
The problem is inside the mp2 inverter.
There is only 1 ct clamp measuring only the AC-IN. Because of that it cannot differentiate between loads on AC-out1 and AC-out2.
A grid meter and non critical loads on ac-in should be able to solve that issue but apparently it is not a priority to victron
It’s more of a case that this wasn’t a use case when these systems were developed.
You can add meters, but in the case of an EV charger, the Victron charger is accessible via modbus and sharing power information so the GX can control the charger as required, so it can typically be installed on AC OUT 1, or AC IN, if you don’t mind it going offline in an outage.
The grid meter can do the same thing and not only for the car charger.
It can take into account the boiler, heat pump, and car loads all at once.
Maybe there is a problem with the grid meter 3 phase regulating but it is giving loads per phase on vrm. So the information of the grid load or main breaker is available.
It’s hard to tell from your diagram. You have 3 sets of AC PV, but you show one meter at AC IN PV only, no external grid meter. If that is accurate, I don’t see how the system would actually know what energy is going where.
I have no problem with the solar panels without a meter. They are all behind the inverter so that’s no problem.
Actually they are 6 sets in total with different brands of inverters and all measured by homewizzard but victron gx device can not see it.
Victron can also not see every load after the inverter but is still able to establish a 0 to the meter in ess mode.
Exactly what @nickdb says, how does the system know what is going on on the grid connection? And how does it know what both PV inverters on AC out are doing?
The peak shaving update states that an external grid meter is needed for parallel loads, and you don’t have one.
The system will not do the maths, and the PV meter is informational only.
