I’ve Grid on AC-In and PV-inverter on AC-Out1.
before upgrading:
Mode:Off: PV-inverter did provide power to grid; no charging, no battery consumption. (AC-Out1 and AC-In was connected)
after upgrade to 558
Mode:Off: AC-Out1 is powerd of by MP2, PV-inverter cannot provide power to grid anymore. (AC-Out1 and AC-In is disconnected)
Is there any way to get back to previous behavior?
In “off-mode” AC IN and OUT should have never been connected.
If you switch off the MultiPlus the transfer switch opens.
It depend on what “off-mode“ you’re talking about. For physical switch you are right (On/off/Charger Only-Switch).
However, I’m talking about MP2 (DBUS) /Mode Position of the switch (1=Charger Only;2=Inverter Only;3=On;4=Off)
”Off” here is used for function-bypass (MP2 is powered but does nothing - no charge/discharge)
Switching off there should also turn off the MultiPlus completely.
I can tall you it was not before 558 (you’ll find lots of examples here). If so, such significant change should appear in change-log.
What would be reason behind this change/limitation? That makes it impossible to feed grid by PV; also usage MP2 as UPS is now limited.
On Victron Professional you can find a text file with a link to a FW archive, there you can download the previous version an try again.
If it works with that version keep it.
I never heard that you can switch a MultiPlus to “passthrough” with that switch.
As Matthias said, with the Multi in Off or Invert Only, the AC input relay is open so there is no way for PV on AC out to feed the grid.
When the Multi is switched off, it SHOULD no longer provide voltage to the AC output. It would be a serious bug and safety issue If the inverter continued to produce voltage at the AC output when switched off.
By design, PV inverters require AC stable where they are connected. This is what shuts them down when the grid fails. Again, a safety issue if nothing else.
An external transfer switch between the Multi output and loads / PV inverter is a good idea. It allows the system to function if the Multi is switched off (maintenance, user choice, etc.) without disrupting loads or PV inverter operation. A manual transfer switch is the least expensive but requires an extra step. An automatic transfer switch could switch to grid when the Multi’s AC output disappears, connecting the grid to loads/PV inverter any time the Multi is turned off.
The behavior is even more significant than initially recognized. You mentioned:
That is definitely incorrect. Even now, with Invert Only, the AC input and AC-Out1 are still connected. (Otherwise, there would be no way to use PV in Invert Only mode if the PV is connected to AC-Out1, as recommended by Victron for UPS.)
However, prior to the update, switching between “Charger Only,” “Inverter Only,” or “On” did not interrupt the connection between the AC input and AC-Out1. Now, any switch momentarily disconnects AC-Out1, causing the PV inverter to detect a power outage.
As from the official drawing (ESS-manual) there essential loads should get powered anytime via PV/inverter (batterie). Not the Out1 but Input gets disconnected in case of power outage. In this case of switching mode or power outage the Out1 should stay connected (Essential Load!).
Reason for disconnect (full power off) would be trigger physical switch off or any critical behavior e.g. battery empty/over-voltage on Out1, …
AC OUT will be powered from the battery if AC IN gets disconnected but turning the MultiPlus OFF means it’s OFF → AC IN relay opens and inverter is switched OFF.
I can’t imagine how it was working in your system before the update.
Did you try to downgrade the FW to the previous version?
That is definitely incorrect. Even now, with Invert Only, the AC input and AC-Out1 are still connected. (Otherwise, there would be no way to use PV in Invert Only mode if the PV is connected to AC-Out1, as recommended by Victron for UPS.)
I think you are confusing AC input and PV connected to OUTPUT of the Multi. PV connected to the AC INPUT would not make its way to the Multi AC output (aka Critical Loads) if the Multi is in Off or Inverter Only since the AC input relay is open in these modes. However, PV connected to the AC OUTPUT should function in all modes except Off.
If a switch between Charger Only and On interrupts the AC input with the latest firmware, then this is a bug. However AC INPUT should be disconnected when switching to Inverter Only or Off.
Switching to Inverter Only should not disrupt the Multi AC OUTPUT.
Switching to Off SHOULD shut down the Mult AC OUTPUT.
If you are seeing your PV inverter shutting down in Inverter Only, then you might check your wiring. If the PV inverter is connected to AC 2 Out then that WILL shut down in Inverter Only. You can change the AC 2 Out behavior in Multi config and it is possible that config setting was lost in the firmware update.
I’ve downgraded the MP2 but was not able to get back previous behavior. Therefore I’m now back on 558.
Regardless, the behavior still seems somewhat suspicious.
Testcases:
Battery 50% charged
“Grid off” means grid power outage
For ‘Essential Power,’ we are experiencing an excessive number of disruption on Out1 incidents.
I’m interested if that behavior can be confirmed by other or if it’s may an issue of the particular device.
While the outcome of the first point (1.) may be anticipated, you might also want to explore an alternative use case for photovoltaic (PV/UPS) applications.
If you consider the drawing above and set the operation mode for the inverter accordingly, you could anticipate:
