solarrex avatar image

Placing 3 phase loads between ET340 Meter and 3 Multiplus II

Hi there!

I am planning an ESS three phase system, and would like to know if it is possible to place three phase loads between the meter (ET340 in this case) and the 3 Multiplus II (one per each phase).

The order of the components would be as follows (from mains to loads):

AC 3 phase Mains (+ Utility meter + mains protections). 230V between phases (127 V between phase and neutral)




-------> 3 phase motor (elevator)


Autotransformer (230V/400V)


Multiplus II + Multiplus II + Multiplus II


<----------- 3 phase Fronius Symo


RCD & ThMg breaker + RCD & ThMg breaker + RCD & ThMg breaker

Loads (mono) + Loads (mono) + Loads (mono)

My main doubt is whether or not is it possible to place a 3 phase load between the ET340 meter and 3 Multiplus II, so normal funcioning of the ESS system does not become affected in terms of metering load and production, as well as orchestrating the overall ESS system.

Thanks !!!

Multiplus-IIFronius3 phase
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Why would you not put this on the MP2 AC2 OUT as this is a direct connection to AC1 and would not affect the MP 2 I would have thought

Do you mean placing the Autotransformer at the output of the three Multiplus II?

But the Multiplus II output works at 230V (400V between phases). The installation as it is now, works at 127V (230V between phases). Isn't it required to adapt voltage at the AC input of the Multiplus II?

The Autotransformer's company has assured that the Auto can generate current both ways, whereas when asked for a transformer, they told me that there is an "input" and there is an "output", but it is not bidirectional.

Or perhaps I did not understand you well Paul B.

Sorry I miss read the question.

and as such I now have no sugestion to offer you

No worries, thank you very much for your interest!

1 Answer
Daniël Boekel (Victron Energy Staff) avatar image
Daniël Boekel (Victron Energy Staff) answered ·

Hi @solarrex

No the ET340 has to be in the 230V/400V part of the system, otherwise it cannot measure correctly.

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