I’ve read in the manuals that the 8, 10, and 15 kVA models require an external transfer switch to operate multiple devices in parallel on the same phase to interface with the utility grid or a generator. However, does anyone know if these inverter models can be used in parallel without the external…

I have asked the Victron factory and they have responded that it is possible to use more than one inverter in parallel per phase in island mode only, without an external transfer switch, without use or connecting the AC In input and with the normal firmware available to date (556). (do not use the …

As far as I am aware the larger models are in no away supported in parallel without a transfer switch. I have queried why the datasheet fails to mention this in a footnote. While technically nothing stops you trying to do this, if it is indeed still unsupported, you will be on your own and without…

[image] nickdb: I have queried why the datasheet fails to mention this in a footnote. Curious what you find out. We have a 2x2 split-phase system consisting of 4 10k Quattros, and had a couple Victron dealers review the design (excluding a transfer switch). EDIT: Hmm maybe the Quattros have d…

[image] A-P: Hmm maybe the Quattros have different requirements vs the Multiplus II? Yes, the external transfer switch is only needed for the bigger MultiPlus-II models. @Heraldo In an off grid system an external transfer switch wouldn’t make sense. So yes, in a 100% off grid system paralle…

MultiPlus II 48/15000 works without external transfer switch

Q&A and troubleshooting

A-P 8 September 2025 14:10 2

They can work fine in parallel without an external transfer switch. Some grid operators require an external switch.

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MultiPlus II 48/15000 works without external transfer switch

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