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tree61 avatar image
tree61 asked

Multiplus 2 AC coupling with Phoenix Inverter

I have an existing solar system with Phoenix 12/1200w 230Vac, now looking to expand the system with multiplus 2. Just wondering if the 2 inverters can operate in parallel AC coupled?

multiplus in parallel
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3 Answers
Kevin Windrem avatar image
Kevin Windrem answered ·

Yes. The solar inverter can be connected to the grid (input side) of the Multi with no restrictions. You can also connect the solar inverter to the output side of the inverter as long as the solar inverter is smaller than the Multi and the battery bank is large enough (one-to-one rule). The advantage of connecting the solar inverter to the output is so you can take advantage of solar energy during a grid outage. When connected to the input side, the solar inverter will shut down with a grid failure so it can't supply AC loads or charge the battery.

If you have a solar inverter or any AC loads on the input side of the Multi you need a meter on the grid connection (before the inverter and loads). I believe the Multi II includes a current probe that would satisfy this requirement.

Victron has lots of documentation about this type of installation including details on the one-to-one rule.

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nickdb avatar image
nickdb answered ·

Just to be clear, though, you can't create a parallel system (a master/slave pair) with disparate systems.

What you are describing is serial connection (cascading) of inverters, which you can do, but technically is not supported.

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Kevin Windrem avatar image
Kevin Windrem answered ·

I misunderstood. Nickdb is correct, you can't parallel the Multi and Phoenix outputs.

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