question

karl4 avatar image
karl4 asked

Multiplus II ESS with generator and transfer switch aux contacts

Hello.


I use Multiplus II (Quattro II does not exists?) and CerboGX as ongrid ESS/UPS system with generator backup.

How connect transfer switch aux to that system for change input from grid to genset on information display? And if possible, also change charging limit settings (and disable feed in ofcource).


Thanks, Karl

Multiplus-IIGenerator
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4 Answers
Matthias Lange - DE avatar image
Matthias Lange - DE answered ·

A Quattro-II is planned for the next few weeks/months.

Grid settings can't be changed via AUX input,but you change the charge current with an assistant.

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karl4 avatar image karl4 commented ·
It's quite pointless buy new hardware (I already have multi II and changeover switch), it should be software (minor) update :(
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shaneyake avatar image
shaneyake answered ·

I would wait for the Quattro-II.

For the Multiplus-II,
You can't change the information to show genset, unless you do it manually.
You can change the charge current as well as disable feed-in via Modbus or NodeRed but this really isn't a great solution as if something goes wrong it could go very wrong for the genset.
LOM's might also be a problem with the genset.

Quattro doesn't have any of these problems as it has separate grid config for each AC-input and includes a change over.

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Kevin Windrem avatar image
Kevin Windrem answered ·

This comes up a lot. It would be great if a digital input to the Multi could tell it which source has been selected via an external transfer switch. A contact on the transfer switch could activate the digital input to the Multi to say "on generator". Then the system could work like a Quatro, switching input current limit and preventing ESS feed-in to the generator.

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shaneyake avatar image shaneyake commented ·
Yes, this would be an awesome feature. SolarEdge has implemented something very similar.
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mrhappy avatar image mrhappy commented ·
I agree, this is a feature I would very much appreciate too...
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dannyclark avatar image dannyclark commented ·

This is something I can’t seem to wrap my head around. Why is it so difficult for the GX device to switch to Generator functionality/display when you use it to start the generator using the relay to begin with?! What am I missing? Regardless if your using assistants or not “GX, start generator and oh yeah, GX I’m using a generator to power you now” ? “GX, shut off the generator, and oh, that means there’s no generator power coming in” ? I’m not a pro by any means, nor an electronics or software person, but why can’t this be a simple solution? Some small logic program.


Or put simply, your telling it to start and stop the generator through its interface already. Why on earth would you have to tell it twice “I’m using/not using the generator.” ?


Pete




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suggarman avatar image
suggarman answered ·

Same problem for me. Multiplus II 3-phase system with byd lvs and solaredge and a manual switch for changing from grid to generator. The LOM-detection needs to be disabled or the multis will not connect the generator. My switch has a dry contact which would be perfect to feed an assistant to disable LOM when on generator.

This is a new feature request :-)

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