question

Kevin Windrem avatar image
Kevin Windrem asked

Common neutral in and out of a Multi/Quatro

I am considering adding a split-phase Quattro to my house electric system to cover grid outages.

In most systems that supplement grid power with say a generator, a transfer switch selects between grid and generator, but only the hot legs are switched and all neutral connections remain interconnected. There is one neutral-safety ground connection at the service entrance.

I'd put a transfer switch on the output of the Quattros to route grid power to the loads in case of Quattro failure. To switch both hots and neutral would require a 3-pole transfer switch which is many times the cost of the typical 2-pole transfer switches available.

Would it be acceptable in this case to connect the Quattro in and out neutrals together? I'd also disable the internal ground relay since the service entrance neutral-safety ground connection would also be active at all times I can't think of a reason this would cause problems unless current sensing inside the Quattro was in the neutral path.

Sorry, I know this has been discussed before but not exactly in this situation.

MultiPlus Quattro Inverter Charger
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1 Answer
markus avatar image
markus answered ·

Hi Kevin,

there are many grid codes that especially support externally joined AC neutrals.bildschirmfoto-2024-02-29-um-214902.png

This shouldn't be an issue.

BR

Markus


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markus avatar image markus ♦♦ commented ·
But if there is no good reason to do it otherwise, I would route the mains power through the Multi/Quattros all the time and only use the transfer switch, to switch the loads from AC-out to AC-in to bypass the Multi/Quattros in case of failure.
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Kevin Windrem avatar image Kevin Windrem markus ♦♦ commented ·
Yes, using the bypass only for Multi/Quattro failure was my plan.
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marius-chirita avatar image marius-chirita markus ♦♦ commented ·

Hi Markus, I was wondering if you have any updates about the turbine controller device you were talking about in 2021. I tried to reply there but the thread was closed. Is there a better improved way to connect wind turbined to victron MPPT controllers ?

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