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oxy avatar image
oxy asked

Quattros in parallel - is it possible to turn one off during off-season?

Hello everyone!

Currently we're running a single 10kW Quattro off-grid, and considering to add a second parallel one to increase peak-load acceptance.

However, these peak loads happen only during the sunny summer season. During the dark winter days current Quattro is more than enough.

I assume that two Quattros use twice more energy running near idle load? Hence, I wonder is it possible/easy/how to turn off the second Quattro for the winter and leave only one running?

Thank you in advance!

MultiPlus Quattro Inverter Chargermultiplus in parallel
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janieronen avatar image janieronen commented ·
One option (not cheapest) is wait and move to Quattro II inverters and that is what I did. They are cheaper and sold my old models out with nice price. That reduces standby power consumption so low that there is no need to shutdown parallel inverters. Also efficiency boost during charging & inverting is a lot better. I had issues to keep room temperature down with old ones so I was looking years to get more efficient inverters.


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4 Answers
Alexandra avatar image
Alexandra answered ·

@Oxy-

No. In parallel they operate as one unit. You will likely see this error.

The only way would be to reprogram the system to stand alone and then switch one off.

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oxy avatar image oxy commented ·

Thanks, @Alexandra ! Is it only reprogramming via VE.Configure or would one need to physically make some changes too? Just trying to understand how time-consuming it would be if done twice a year.

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Alexandra avatar image Alexandra ♦ oxy commented ·

The main one would be to remove the ve bus connection between the two.

In theory you would want to remove the unit from the system electrically. But I dont see that as totally necessary. How it is wired? From one AC in and to one AC out?

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Alexandra avatar image Alexandra ♦ Alexandra ♦ commented ·
@Oxy-

Electrical isolation is best. That is why I asked about the electrical set up. Can you just disconnect with breakers/isolators? Physically removing the device is not necessary.

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oxy avatar image oxy Alexandra ♦ commented ·

Currently, I don’t have the second Quattro, hence the question :) Thanks for help!

p.s.

> From one AC in and to one AC out?

That seems not the parallel way, but maybe I misunderstood. Out of curiosity, have you tried such configuration? Feeding one inverter to the other for PowerAdsist?

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derrick thomas avatar image
derrick thomas answered ·

I have 2 MP2 in parallel. I have on a few occasions turned one off and reconfigure the other back to stand alone. All I did was turn the switch off on the second unit then reconfigure the first. Never unplugged the Vebus from the second unit and didn't mess with wiring at all. Never had any problems doing that.

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atne avatar image
atne answered ·

i have in diferent systems any 3 MP3 parallel in this moment i turn on of this off the system go offline in service mode
And all i read and found about this is this the rigth way..

Only way to only turn one of.
But than you also have a brake
wint VE Queick Bus open the parallel turn the other of and do the one you want work in single mode but without any brake i think is inpossible


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Kevin Windrem avatar image
Kevin Windrem answered ·

I would disconnect the output connections from the powered down unit. Otherwise, AC power from the load side of the active Quattro will back feed into the output of the Quattro that is turned off.

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nickdb avatar image nickdb ♦♦ commented ·
In a parallel set input and output of each inverter should have dedicated isolators.

These must be dropped and the system turned off.

Once a unit has been reconfigured as standalone, the remaining unit will need to be wiped so it can be added back as a parallel system.

Done this many times myself for troubleshooting, makes it easy to power either on individually if there is a problem.

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derrick thomas avatar image derrick thomas commented ·
I wonder what is Victron's official position on this? Maybe they can chime in here? I'm wondering if there is a potential for damage by not disconnecting the powered down unit. @mvader (Victron Energy) @Guy Stewart (Victron Community Manager)
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Alexandra avatar image Alexandra ♦ derrick thomas commented ·
@derrick thomas

I think the official position on electrical safety is a regulatory and safety concern not really a victron related question.

You would obviously want your equipment to be safe as well. But a unit switched off and installed with correct isolation would be safe indefinitely.

The complete isolation if you are being serious about the parasite watts would be necessary as there would still be capacitors and electronics there.

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derrick thomas avatar image derrick thomas Alexandra ♦ commented ·
@Alexandra safety concerns and all that completely understood, and I agree with you that full isolation would be the best practice. However inquiring minds want to know. I am curious from a purely mechanical point of view if there is any potential for damage to the multis by not isolating the offline unit.
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Alexandra avatar image Alexandra ♦ derrick thomas commented ·
From the standpoint of a Victron inverter connected to a system but not switched on, there will be no problems for the unit. There can be damage from external unforseen factors/problems. This would be true for any inverters hooked up but not in use.
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