I have a three-phase system with six Multiplus II 5000 kva pairs of 2 in parallel. From time to time, almost daily, and sometimes twice a day, the system shuts down only the non-critical output (AC output 2) for a few minutes. When the power returns to the output it is preceded by a contactor noise. This leads me to believe that the system does this intentionally and in concert for all 3 phases. This voltage drop is never preceded by any alarm or overload error or anything related to the battery operation, it does it both when the battery is at 100% SOC and when it is at 50% SOC. I have also set the non-critical output to be covered by the energy from the battery but it behaves the same. Is there a setting that governs this behavior, where should I look for this?
Standard behavior is ac output 2 is only powered when ac input is powered and connected. Start by checking to see if ac input was dropped for some reason. Behavior of ac output 2 can be changed with ve configure.
there is no grid lost before or during this voltage drop, there is no other error or warning. Even if I set AC output 2 to be served by the battery at grid lost (Self-consumption from battery= All system loads) the voltage drop still occurs
If both outputs are doing it then the whole system is dropping out. With parallel systems this can happen for some many reasons and the logging can miss it especially if the GX is also loosing power.
Since it is a parallel set up this can be any number of things from current sharing and wiring to a comms interference problem.
No, only “AC output 2” is interrupted without grid lost or other error around it. When “AC output 2” is activated a relay, contactor noise is heard from the Multiplus.
I would like to understand under what conditions the Multiplus decides to disable AC Output 2. Is there a way to trace or log the reason(s) for this?
In my setup, I get more frequent disconnections on non-critical loads than if those loads were connected directly to the grid.
Another strange issue, possibly related, is that the setting “Self-consumption from battery = All system loads” doesn’t seem to work. When the grid is lost and AC Output 2 is disabled, the battery does not support the non-critical loads, even at 100% SOC. This may be a sign that something is misconfigured.
Details:
-
AC Output 2 has been configured for ~4–5 weeks.
-
The system has been running for ~2 years, during which I solved multiple issues step by step.
-
All 6 Multiplus units are from the same production batch and up to date firmware.
-
Smart meter: Carlo Gavazzi.
What I already tested:
-
GX device power supply → not the cause.
-
Communication with the smart meter → not the cause.
Any guidance on how to trace the actual trigger for AC Output 2 shutdown would be very helpful.
It seems that after the Gx update to V3.65-3 the malfunction no longer occurs. It’s been almost a week since the update.