aldo avatar image

Multi Quattro - Fronius Primo - ESS - Dedicated Virtual Switch

Good morning to the community

I have a lot of doubts about the my system and can't find any answers.

I have a system of:

10KwHof solar panels.

PV solar Fronius 8.2

80 KwH of lithium batteries connected via Can Bus

Actually I am using the ESS assistant

Unfortunately I am very confused because my dealer insists that where I live (Kenya) it is not recommended to use ESS.

But it seemed to me the only alternative to have the Feed In 0. He tried it with contactor connected to a relay, but nothing worked well.

In ESS is worked well for a year, then there were problems with the charger section of the Victron the Victron was replaced promptly.

Now after another year I have a similar problem when connecting the mains the multi makes a lot of noise it switches from Bulk to Passtrough and disconnects the mains and does this all the time.

If I manually disconnect the grid the system works perfectly as an inverter.

I was considering the dedicated virtual Switch, to physically disconnect as much as possible, but how will the feed IN 0 work ?

Any suggestion?

Thank you

ESSvirtual switchquattro 10kva
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3 Answers
Alexandra avatar image
Alexandra answered ·


Are you following the 1:1 rule with the Victron?

If you read the ESS manual, you will see it is not recommended to use ess if you are wanting to ignore the grid. And virtual switch does not work with ESS assistant, you have to disable virtu switch to programm the ess assistant.


It is best to use the PV assistant with ac ignore assistant.

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aldo avatar image
aldo answered ·

@Alexandra Now I'm even more confused. I try to explain better the answer does not seem relevant to me. I didn't say I want to ignore the network, otherwise I wouldn't worry about zero-feed-in. I know rule number one.

I am saying that in the face of a slightly unstable network, what contraindications are there in using ESS? Is it possible that this could damage the Quattro?

I would like to leave the multi connected to the grid and use the energy produced with ESS Optimized whit battery life as much as possible and I am doing it, but the dealer says that Victron says it is not advisable.

PS when I say unstable I mean a network that has stable voltage but has 3 or 4 power cuts per week, I have also a 100 Ah stabilizer.

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Yes i understand unstable grid. We are in Zimbabwe. The main problem is usually not blackouts but brown outs. So we narrow the disconnect voltages and change the LOM detection to what works best so there is no overload on grid disconnect.

ESS is designed to work with grid. All its features are designed for that. Like the optimisated with battery life, it uses the grid to power loads while concentrating on charging up your batteries. If the grid is not there it cannot manage that. If you are mostly connected you should be fine. The AC pv is still controlled with frequency shifting if it is setup correctly even when the grid is out.

PV assistant works for offgrid control. It uses frequency control. It also stops AC PV production when grid is connected.

The feed in zero is done by GX control if they are set up and communicate with one another.

Your passthrough problems are probably caused by something else.

Have you updated all the components in the system?

aldo avatar image aldo Alexandra ♦ ·

@Alexandra Thank you for your reply.

I have tried configuring the system and using the virtual switch actually works without any problems.

I just wonder if this way the Fronius is controlled by the GX when it produces and the batteries are full.

The way to tell would be to check if there is frequency shifting on the vrm. Or on the gx itself under the inverter in devices. You would normally see around 50hz for notmal operations; 52 to 53hz if the system is throttling the Fronius.
aldo avatar image
aldo answered ·
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Risultati della traduzione

Unfortunately it does not work.
Today a day of full sun, the Victron Quattro turned off because in over charge and the Fronius was charged at full capacity.
So ESS is not a suitable
Virtual Switch is not suitable.

195 / 5.000

Risultati della traduzioneUnfortunately it does not do so today a day of full sun, the Victron turned off because in over charge the Fronius charged at full capacity. So ESS is not a suitable system while Virtual Switch neither.

1 comment
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Have you followed the instruction on the Fronius Victron page? And set up the Fronius to receive communications from the GX device in the system? And is the fronius set up to communicate with the Victron.

On your battery side, try reducing your battery charged voltages a little bit, this is related to the pass through problem as well. something is not happy on your battery side.

Either it is undersized or your charged voltages are set too high for the BMS in question. What batteries do you have? I am surprised your local dealership cannot help you.

Vrirtual switch would not work as there is no assistant for the Victron to use to control the Fronius. You either need ESS (for On grid use - with occasional power cuts) or the PV Assistant (offgrid use).