question

asuelberg avatar image
asuelberg asked

3 phase Multi not charging at all when one phase disconnected

We are running 3x MultiPlus-II 48/5000/70-48 in a 3 phase configuration, one unit per phase. The system ist backed by about 1000Ah of battery, custom BMS. 3 phases are required to run a heat pump. During summer, solar will charge the battery. In winter it is required to recharge the battery when the electricity is cheap (hourly price change). The system is run in ESS manual mode to be able to switch between operation modes.


The circuit breaker of AC in phase 3 tripped. The system is now reporting a "Grid alarm: Grid lost" fault. Nobody can reset the breaker for a few weeks.


Due to the fault, the two "healty" Multiplus units do not recharge the battery, even if the could. Running as pure inverters works fine on all 3 units, including the one with the faulty AC input.


Is there an option to get the remaining 2 units to recharge the battery on demand? Neither reconfiguring the system to 3 individual units nor deactivating the LOM protection seems like a good idea.


Thanks & greetings from Sweden!


Firmware 502, Cerbo GX firmware 2.93. Controlled via the Victron modbusTCP integration in HomeAssistant. Installation 252966

Multiplus-IIbattery charging3 phase
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1 Answer
Alexandra avatar image
Alexandra answered ·

@asuelberg

With ESS assistant installed they switch as a group.

The only way to have some connect and some not for charging is to have switched a group off but it means you lose ESS assistant. You can still keep the three phase though.

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