I have had the Shelly Pro 3EM integrated as a grid meter via WS for quite some time. This works quite well, but it has been causing intermittent
problems for the past few weeks. Even though both devices show as connected, the values being sent do not change. Only after restarting the Cerbo GX do the
grid import values start changing again. I have not made any changes to the settings .
I have now seen that new firmware is available for the GX and installed it straight away. However, the problem still persists, although I noticed that Shelly devices can now simply be integrated. So I selected the 3EM. The integration worked immediately, and the Pro 3EM is also recognised as an âenergy meterâ (including in the VRM Portal!).
However, here comes the problem⊠in the setup, you cannot select that it is a meter.
Consequently, nothing corresponding is displayed in the Cerbo console (under the grid icon) either (although as a device it does show all
phases, etc., as well as the import)
Is there another trick, or do I have to bite the bullet and create it as a virtual device in Node-RED after all?
All devices are running the latest firmware and have a static IP.
As far as I understand it, some Shelly smart meters are now integrated directly into Venus OS and donât require a separate script, but they canât be used as grid meters. This is apparently due to the sampling rates, which are too slow for grid meters and the associated control functions, and are therefore not approved. So Victron wonât officially allow any meter to be used as a grid meter if it doesnât meet the requirements. The solution using the script was never officially supported anyway.
And which exact smart meter do you have? The Shelly 3EM probably isnât officially supported either. My 3EM isnât detected at all, for example⊠Could it be that you mean the Pro 3EM?
Hereâs the relevant paragraph from the documentation:
However, the Shelly devices arenât only too slow for Victron.
According to VDE requirements, grid sensors for battery storage systems must have a response time of no more than 200 ms, which rules out the Shelly devices.
although the sampling rate is too low for Victron, it can still be used to control an ESS via the grid setpoint. however, Iâve also had the problem that occasionally my 3EM returns no values at all â everything is 0. since I only use it for display purposes, this isnât a problem. however, I havenât yet analysed exactly where the problem occurs.
I also tried once to find out how long the control delay is with the ESS and arrived at approximately 1 second, measured using the data the system provides via the Multi.
In my three-phase system, the control loop is so slow that I draw around 0.5 kWh from the grid every day due to control delays. The Shellysâ sampling rate shouldnât make much difference there, and Iâd welcome the option to officially use them as grid meters. The dbus script hackery is much worse, after all.
Well, whether the control delay makes any difference .. that also depends very much on the household load. If it only fluctuates a little, then it doesnât matter.
And whether 0.5 kWh from the grid is a lot or a little .. well, that depends on the total household consumption.. and if it still bothers you.. just set the grid setpoint to -50 W. But of course it also depends on where youâre getting the power from ;O))))
That comes from the PV system. I had experimented with different âgrid set pointsâ, but in the end I set it back to 0. I have a few pumps that draw relatively a lot of power and run for short periods (a well pump and a sewage treatment plant with three pumps; if that one ever gives up the ghost, Iâll get one with a compressor). At â50 W, too much is lost on poor days compared with the amount saved on grid imports, so the battery wouldnât reach full charge. Of course, you could use Node-RED to adjust the grid set point according to the PV forecast.
As already mentioned above, the Shelly devices are too slow even as grid sensors to meet the standard, which requires a response time of 200 ms or less.
So even if Victron supported them as grid sensors, they would not be permitted to be used as such in Germany.
I have an EM540 on the live installation: 100 ms, but that doesnât help with faster control response either. The EM24: 600 ms according to https://www.victronenergy.com/upload/documents/Datasheet-Energy-Meters-Selection-Guide-DE.pdf is permitted and supported by Victron. Or am I reading that incorrectly? It also says: âPlease note that the latency of the GX device (the time required to read at 9600 baud) is between 180 and 250 ms.â So much for 200 ms.
I only spoke up here because, for the sake of experimentation, I wanted to set up the Shelly Pro3EM as a grid meter on my test installation, but it didnât work. This thread made me realise that Iâm not just being stupid.
They could also simply support the Shelly as a grid meter for non-ESS applications.
As far as I remember, the 200 ms requirement was only introduced in the latest version of FNN 4105, so it is still fairly recent. The EM24 is therefore indeed no longer recommended.
The EM24 has also been unavailable for quite some time now (apart from the Ethernet version).
The EM24 can still be used to measure loads or generators.
@faceman
Victron doesnât make the regulations and presumably doesnât care about some of them either, since the requirements differ from one country to another.
The installer of a system is responsible for complying with the local regulations.
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The integration worked immediately, and the Pro 3EM is also recognised as an âenergy meterâ (including in the VRM Portal!).
. Perhaps someone else has some information. And yes, thatâs right, I have a Pro 3EM.