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Henning Schneider avatar image
Henning Schneider asked

MultiPlus-II GX and Generator ATS

Good Morning,

various leaflets and schematics showing the MultiPlus-II GX setup with an ATS for Grid and Gentset and a PV array with MPPT.
Here is the question:
In a few other posts, people mentioning the Aux output (either the Relay on the Multi or the one on the Cerbo GX) to start the generator, after LOM detected "grid is off". The ATS will subsequently switch over to the Genset.
OK, AC-IN L1 will have power from the Genset now.
How does the Multi know, that AC-IN L1 is on the Genset?
I must assume, that the Multi or the Cerbo will switch off the Genset after detecting power at AC-In L1 and end up in a loop until the grid is back online and the ATS switches back to its primary power source.
It must be possible to utilize the Digital inputs for this purpose, i.E. for "feed-in" off (would be a serious problem, if left on, with certain generators), or "charge batteries from the Multi allowed", to utilize the power from the Generator, or "leave AC-Out 2 switched on".

Thanks
Henning

Generator
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3 Answers
Trevor Bird avatar image
Trevor Bird answered ·

These diagrams are not schematics. They are a representation of what may be possible if you would like to engineer a solution. You can parallel generators to mains ( I used to write PLC software to do that) but you need a use case and you need to be committed to ensure you are prepared to provide the infrastructure to achieve the required outcome.

By purchasing a Multi you don’t have the entire solution. Those simple diagrammatic overall diagrams obviously don’t go into the detail of what is required. That is the beauty of the Quattro because it addresses in the one box so many of the complexities of mixing mains with generator. The beauty is the ability to allow a relatively small generator to handle the inrush currents that would normally demand a large generator. By using the Quattro huge savings can be realised.

To answer one question though if you used the Cerbo to start the generator the Cerbo understand the generator is running. In order to do what you want to be achieved you may need to program a simple PLC to provide inputs to the Cerbo so the complexity of your needs can be realised through a PLC algorithm.


It would be good to know what your requirements are.

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Henning Schneider avatar image
Henning Schneider answered ·

Good Morning, I have an PLC-driven Transfer switch and good sized Generator.
That is not the problem. I can also use an external device for LOM detection (a bit costly, but so be it). The actual Problem is switching the ESS, incl. "feed-in" off, to avoid problems with the Generator back-end. This must be possible somehow. I dont have a Cerbo, since the GX device is already built-in.

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Henning Schneider avatar image
Henning Schneider answered ·

Hi Shaneyake, brilliant, I will implement this solution over the weekend.
Thanks a lot.
Henning

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