mr-no avatar image
mr-no asked

Multi RS Solar Setup Questions


I am planning to buy the Victron Mult RS Solar and have tried to get some information from the datasheet/manual/forum/DemoApp, but there are still some unanswered questions. I hope someone can help.

My planned setup:

- connecting the solar modules to the internal MPPT solar charger.

- connection of lead-AGM batteries

- connection of the public grid to the ACin connector

- only loads at output ACout1 (no connection to the public grid there)

The loads should be supplied by the inverter when the SOC of the battery is >70%. Below this value, the Mult RS Solar should switch the output to the utility grid (ACin) until the battery has again e.g. >80% SOC. Goal: The loads should be supplied primarily from PV and battery, but the battery should not be discharged below 70%, except there is no grid power. Also, I don't want any power feeding back to the public grid (from the ACin connection).

My questions:

1. is it possible to set up the Mult RS Solar to work as described?

2. can it be ensured that there is no grid feed-in over the ACin connector?

3. how fast is the internal transfer switch, if there is one (could not find a description in the manual and datasheet, but there are such symbols on the front of the unit). Is the switching synchronized with the mains frequency/phase? Is it the same transfer switch as described in the Multiplus II?


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3 Answers
mr-no avatar image
mr-no answered ·

Nobody had an answer. So I will answer it by myself ;)

I bought a Multi RS Solar at my own risk and have tested and measured the behavior. I must say, the RS is a really good device and does fullfill all my requirements. I can only blame the lack of information in the manual or from other Victron information sources I checked - at least the information was not sufficient for my application.

Here some brief answers to my questions. Perhaps other can benefit from it.

1. yes, such a setup is possible (other than asked, I am controlling everything by the battery voltage and not by SOC, but that might also work - did not test it up to now)

2. I have not seen any grid feed in (continuously measured by a separate meter at ACin)

3. Now I know that it is not a real transfer switch. The Multi RS inverter output (ACout1) instead connects and disconnects to the power grid (ACin) depending on the operating condition. It is rather a hook up. This happens without any interruption (measured with an oscilloscope).

I am running on Firmware V1.11

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gabius avatar image
gabius answered ·

The multi rs solar, can’t feed the grid yet, (sadly for me)

I use it with the same purpose as you, but with lifepo4 batteries, Pylontech, and now I added some diy battery Lifepo4, for a total of 25kwh.

The multi rs solar is really powerful and has a tons of options, I’m just waiting for the feed in greed option.

It’s sad not a lot of ppl talk about it, cause it’s so good in many cases.

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diamond avatar image
diamond answered ·

Hi mr-no, and gabius,

I've installed an RS for a customer with a similar requirement, and though I know it can be done I'm yet to get the programming right.
It's set up as an off-grid system with AC-in connected to grid.
It has a BYD Lithium battery stack so I've set the charger to start when SoC hits 10% (and stop again when it hits 20%)
But this morning it didn't work.....! The battery went flat.
I used the Victron Connect app to set the parameters above.
I'm yet to get back onsite, so hoping for advice before I get there.
Screenshots of the app would be awesome,!?


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