laurent74 avatar image
laurent74 asked

Victron Quattro Power assist configuration problem ?

Hello guys,

I'm living on my sailboat, equipped with a Victron Quattro 12V/220V/3000W and a marine Genset. I'm actually trying to find a way to start my diving compressor, which is a 220V single phase motor 2.2kw, his starting current peak is about 45A.

My genset is a small model, and himself He's not able to provide enough to compensate the Starting peak current demand. So i connect the genset with the Quattro and in theory the genset power + the power assist should be enough to start this diving compressor. But it's not working, i first believe it's because my genset is really to small, but in fact not. See below another test i did and please if you have any suggestion don't hesitate to answer.

When i connect this diving compressor directly to the 220V/16A outlet of the harbor, the diving compressor start and run perfectly.

When i connect this 220V/16A outlet to my "AC in" of the Quattro and the diving compressor is connected to the "AC out", the diving compressor is not able to start! If I'm right, the Diving compressor should be able to start as the Harbor outlet is able to do it, and at least if a little Amps is required for the starting peak, the Quattro should be providing it and the total of this both current should allow the start of the diving compressor. But it's not doing it, I can just hear the Diving compressor motor "growling" but not more!

Do you know if there is any parameter(s)that i should adjust in the Quattro, to allow the full Shore outlet going into the AC out, or if there is a "protection timer" to adjust or something like that ?

Because actually i don't understand if the Quattro is absorbing power of the outlet shore and from that the AC out is not strong enough to start my compressor. Or if the Quattro is stopping the current by the configuration of a thermical protection, timer protection or any "protection" that limit the AC out !

Thank you very much for all the suggestions and ideas that you can offer.

Best regards.


current limitpowerassistshorepower
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3 Answers
Matthias Lange - DE avatar image
Matthias Lange - DE answered ·

What does the Quattro if you try to start the compressor at shore power + Quattro?

You maybe should consider to install a softstarter for the compressor to reduce the surge current.

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it's switching from the mode "mains on" to "inverter"and after few seconds (starting button of the diving compressor released) the quattro come back to the "mains on".

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So I guess the Quattro is disconnecting the shore because the voltage is dropping to much due to the surge current.

2.2kW is a heavy load for a Quattro or a generator.
We used to install softstarters for cooling compressors with only 900W to start them properly on a 3kVA MultiPlus.

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laurent74 avatar image laurent74 Matthias Lange - DE ♦ ·

But is it normal that the shore alone is able to run the compressor and so it's not possible to it with the shore connect through the Quattro ?

I thought that the Quattro was not limiting the shore voltage but only adding power in case of peak demand ...

I don't know how works the soft starter, is it possible to find one for my need ? could you advice me on that ?

Thank you very much, Mattias.

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For the compressor itself it doesn't matter the the AC voltage is dropping and because of that it starts connected directly to the shore power.

But the Quattro measures the AC input voltage and disconnects if it gets to low (a to long and/or thin wiring from the main harbor fuse box to your socket and to the Quattro). The lowes (default) disconnect voltage is 180V.

The surge current is to high/to fast for the Quattro to start assisting.

Sorry but I can't help you with the softstarter we didn't install those by our self it was installed by the company that installed the cooling compressor.
But I think it was a "Simens SIRIUS" idk the precise name.

But even with that a 2.2kW compressor can be to much.
As I wrote above we used it with a 900W compressor, two 450W compressors started one after the other to be precise, starting both at the same time still overloaded the 3kVA Multi.

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pekie avatar image
pekie answered ·

Hi Laurant,

I have the same problem on my boat but with a water maker. I tried different soft starters but with no results. I guess the inrush current is just too high. Lately I found out that my battery bank needs replacement and I am now thinking that maybe that's the reason power assist isn't working. The inverter can't just get enough power from the batteries and disconnects. It's only a thought but you might and to check your batteries.

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laurent74 avatar image
laurent74 answered ·


well, weeks are gone and few evolution on my boat are done.

I've had problems with my battery banks and i also found that my generator was in trouble.

I've found that the Fischer Panda 4500fcb wasn't able to deliver a stabilized 220V output. In fact the Capacitors in the AC outlet box were out of tolerance (3 of them on a total of 4 capacitors). Now the generator is able to maintain the output 220V. Unfortunately my diving compressor is still not starting, even if i can see a clear evolution from before, as it start turning a little bit more than before. But still crash the quattro.

Then my battery bank has been replaced, now i'm running 2 brand new Lithium Battery 200AH each installed on parrallel bank, so 12V 400Ah.

Voltage is quite constant even with high load demand, the battery bank is not hoing under 13.2V. I've expected that it would be enough to start the diving compressor, but no ... still making 1-2 revs and then the quattro alert "Surcharge" appear (which i've never have before).

Power factor at 2 (default value) or power factor at 0.4 (in accordance with the total quattro power 3000w) is the same result!

I'm sad to see that the "power assist" is not able to help the starting, as it should be able to do it on the paper, and because the max amps demand is lower than the Diving compressor Starting peak!

I've find that a solution with a Eaton soft starter DS7 could be a solution, but again it will cost 500$ and i'm not sure of the success !

If anybody has any ideas or possible solution to offer ?

You're welcome.



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