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matt1309 avatar image
matt1309 asked

Trying to understand parallel installations limitations

Hi Folks,

I feel I have a decent understanding of single phase/single unit install. However I've got a few queries on paralleling multiplus units.


1. What happens if slave unit goes down/turned off. Does master continue to operate as normal you just have less output capacity.

2. Can you have both units connected on ACIN but only one on ACOUT? ie you have lots of loads grid side but very few on ACOUT1. Similarly vice versa can you have just one unit connected to the grid but 2 units in parallel on ACOUT1 side?

3. Limits within ESS settings and DVCC on GX device are those per unit or overall. ie Limit inverter power and Limit charge current. Are these per multiplus or are they in total?


ESSmultiplus in parallelDVCC
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2 Answers
Alexandra avatar image
Alexandra answered ·

@matt1309

1. No. Once programmed they behave as one unit. As if they are one inverter. So if one is off, they both are.

2. There would be no point to the parrallel system if only one had AC out connected since the idea is to add the power of the two together.

One unit connected to grid and the other not, (i have not tried), you can in a three phase system but you have to have switched as a group off and you will not be able to have ESS assistant at all.

3. DVCC is system wide limiting.

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matt1309 avatar image matt1309 commented ·
Thanks @Alexandra


On 2. I wanted to have more power on grid side, but setup on the weekend and worked as you said.


Dont suppose you know of a way of automatically changing DVCC at night?

I charge from grid in winter overnight but dont want to stress batteries/system with the full amps. Appears no option in ESS schedule charging for limiting charge current.

Is node red + modbus node my best bet to automate this or is there an option I'm missing.

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Justin Cook avatar image
Justin Cook answered ·

Parallel and 3-phase systems definitely get into the more complex side of things; I suggest having a read through this document and all associated linked documents therein to get an initial feel for the setup, wiring, and programming requirements as well as the fundamental operational theory: Parallel, Split- and 3-Phase VE.Bus System Manual

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