[3-Phase System] MultiPlus-II: No charging on one phase, no errors/alarms

Q&A and troubleshooting
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1

Hi everyone,

I am facing a strange issue with my 3-phase ESS setup. The system refuses to charge the battery from one specific phase (AC-In), while the other two phases are charging normally.

System Configuration:

  • Inverters: 3x Victron MultiPlus-II 48/5000/70-50 (Configured as a 3-phase system).

  • Battery: Pylontech

  • GX Device: Cerbo GX running Venus OS v[3.67].

  • Firmware: Inverters are running firmware v[2623558].

The Issue: Despite the battery SOC being low and the system requiring a charge:

  1. L2 and L3 are charging the battery.

  2. L1 sits at 0W charge or just passes through the loads, even though AC-Input is available and within range.

  3. Crucially: There are no error codes, no VE.Bus alarms, and no LED warnings on the unit itself.

Question: Has anyone experienced a single phase “ignoring” the charge command in a 3-phase cluster? Could this be related to a specific ESS parameter or a grid detection sensitivity issue on that specific unit?

Any advice on what to check would be greatly appreciated.

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UPDATE:

After a while, charging started from the first phase, but still not at full power.

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2

Hi @sapdemon, welcome to our community :slight_smile:

Are you absolutely sure you have the same configuration loaded on all three Multis?

This kind of strange, seemingly unexplainable behavior is quite often caused by configuration mismatches. Check whether charging isn’t accidentally disabled on that one phase, or if the charge current is set to 0 A

3

Hi @tstiller

Thank you for responding so quickly.

Yes, I am sure that the configuration is the same for all three multipliers; I downloaded it myself.

I did not notice a similar problem earlier, for example, when importing yesterday’s charging data.

for Today issue:

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Yesterday:

All three phases were loaded at roughly the same level. And the charging current was approaching the maximum possible. There are currently no restrictions from the BMS (lvl 259A).

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4

If you’re sure the configuration is exactly the same in all three cases, then the next thing I’d start with is checking the DC connections. Check the voltage on the terminals of each Multi individually with a multimeter as well. Maybe there’s a loose connection there? Do you have the V-sense terminals connected?

Am I right in understanding that your batteries are connected to the Cerbo and DVCC is enabled?

Also try deliberately limiting the charging current to 50 A on each Multi separately and see how the system behaves then. Will it still charge from L2 and L3 at 50 A, while there’s no charging on L1?