question

Lyndsay Cotton avatar image
Lyndsay Cotton asked

Parallelling a three-phase with a set of Multi's and a set of Quattro's

So, I don't want to complicate my life but here is the scenario:

Three phase installation

Installation already has 3 x Fronius Primo and 3 x 5kVa Multiplus (not the 2)

My client needs to expand. Is is a rural application but grid feedback is also required for export income.

Presently the Fronius have all the solar modules. I need to add more capacity to the Victron and want to add 3 x Quattro's and Mppts for DCPV. I would like to avoid removing the Mulitiplus's.

I need the Quattro's for the 3-phase generator input

Could one parallel the multi and the Quattro's

Is this asking for trouble? Surely we are adding two parallel supplies? Is the limitation on the VRM ?


MultiPlus Quattro Inverter Chargermultiplus in parallel
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3 Answers
marekp avatar image
marekp answered ·

@Lyndsay Cotton

As general rule, all units in 3 phase or/and parallel setups must be the same type and preferably from the same production year.

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Lyndsay Cotton avatar image
Lyndsay Cotton answered ·

After digging here, it is clear this cannot be done.

Then following with scenario 2 which I see was asked previously. I cannot see an acceptable explanation?

What if I add my existing 3 Multiplus (in parallel) to the AC out on one of the Quattro. (The Quattro are in a 3-phase setup)

The client has a 10kw single phase kiln

This could sort out the single phase imbalance I'm sitting with. I guessing though that any form of monitoring or control on the 3 multis is out of the question without a separate GX device

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marekp avatar image
marekp answered ·

@Lyndsay Cotton

Do your client needs that kiln to run when grid is gone?

You can make the parallel system with MPs and use a generator to charge battery directly. This way you do not need a Quattro. The only question is, how old the current MPs are. Can they work in parallel with the current production units?

When you charge the battery directly, you can use cheaper 1-phase generator. This generator is working with its optimal/stable parameters that gives you fuel economy, because it starts when battery is low and stops when is full.

Edited: MP-II changed to MP

2 comments
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nickdb avatar image nickdb ♦♦ commented ·
He said they weren't MP2's - ie original multis. Zero chance of doing anything with them, apart from installing alongside a newer setup, to service smaller loads, but probably better to just toss them and start again, someone will buy them second-hand.
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marekp avatar image marekp nickdb ♦♦ commented ·
You are right. My bad, but the old MPs are still available and some say (my V distributor for one) that they are more reliable than MP-II.
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