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bbmz avatar image
bbmz asked

ESS (mode 3) - separat control-register for parallel configuration

Hello everyone,

I am using an ESS system in „mode 3“-configuration. The installation and control via Modbus TCP is principially working, but there is an open question regarding the usage of parallel configurations / several inverters on one phase.

From my point of view there are only 3 registers / values - one per phase - in the register-list to control the operating-point of the MP-II inverters. Is there a possibility to set the values independently for multiple devices on one phase or is the sum always splitted automatically?

The efficiency of the MP-II varies widely on the usage and especially in low-load situations it would be very useful to only use one inverter. In ESS (mode 1) the system does it automatically, but in ESS (mode 3) there seems to be a lack of control-registers to achieve this goal.


Has anyone an idea how to realize this functionality? Is it possible to configure the second set of inverters as a seperate ESS (with therefore own modbus-registers)? Can separate ESS exist in parallel and be controlled by the same cerbo, shunt, etc. and use the same battery system? Does it help to configure the MP-IIs to a separate 3-phase input group?

Multiplus-IIESSModbus TCP3 phasemultiplus in parallel
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2 Answers
Kevin Windrem avatar image
Kevin Windrem answered ·

Inverter/chargers running in parallel must be configured identically with equal length cables. It is not possible to control each of the units separately. They function as a single unit. If you attempted to run multiple units in parallel without them being configured for parallel operation I suspect damage would result.

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korben avatar image
korben answered ·

Controlling my 3 MP2 (in 3-phase system) through MK3 (i.e. in mode 3) I can set any power to any MP2 in the chain.

It has nothing to do with parallel operation and for sure there will be no any "damage" in 3-phase system if you control your phases individually. 3-phase system can absolutely have different loads at each phase.

However, in most cases this (separate phase control) has very little sense. Given you are billed by total sum of the phases and your loads are reasonable balanced between phases.

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