question

Three old SMA's, which due to output power can not be connected to the output of the quattro's.

It's not clear to me what you mean with 'by the end 24'?

The PV inverter energy is being measured as told in manual part 2.1.2

For the moment there is no grid meter installed. And you can clearly see it goes wrong at the grid calcalution.

Venus OS does calculate that -1040W is flowing to the grid, which is correct.

In the same way it could calculate that per phase.

L1 would then be: - 479W (energy produced) +153W (energy taken by quattro + loads) = - 326W

L2 would then be: - 517W (energy produced) +212W (energy taken by quattro + loads) = - 305W

L3 would then be: - 493W (energy produced) +86W (energy taken by quattro + loads) = - 407W

But instead of doing the calculation, it takes over the input powers of the quattro, which is AC loads + quattro's own energy usage.

And in this case GRID POWER is not the same as QUATTRO INPUT POWER, which the systems knows (because the PV inverter is being told in Venus OS to be installed on the input)

Solution: if being told to Venus OS that an energy meter is installed as PV inverter, and is installed on the input of the quattro's (or MultiPlus, I think the same error will occur), it should not take over the Quattro's input current but calculate per phase (as done just here above)

I know I could get it working by replacing the EM24's position and assign it as grid meter, but not only does my client loses the PV gain function then, I will also need to recable the whole thing. It's a site with multiple buildings and the place where the installation is, is about 100m away of where the grid enters the building.

@mvader (Victron Energy) can you please check this?

I think the problem is that you need an external grid meter if you have connected AC PV power on the input.

If you use the internal measurement of the Quattros as grid meter you can't have loads or PV interters connected at the AC IN.

So you will need a second EM24* and use it as grid meter.

*or a cheaper ET340; use the ET340 as PV meter and the EM24 as grid meter

Hey @Matthias Lange - DE

Thanks for your answer.

I understand the principle, but you have to understand that is an extra cost (material + work), when all the info is there already. (Exact calculation is shown above).

A solution could be that under settings - ess - grid metering an extra option could be added.

Next to “external meter” or “inverter/charger” there could be an option:

“Inverter/charger with PV meter on input”

Because all the info is there, I’m still conviced the installation should work.

Thanks

Frederic

@Matthias Lange - DE @Alexandra

What my client noticed is that the info on the GX Touch is correct by showing negative phase numbers. On VRM it shows the numbers of quattro in. So if it would take the numbers, as seen on the display, the installation would work also.