Is it possible to configure a Multiplus to use the charger only and have no 'grid assist'

[Robbert]

I live on Bonaire, and we have a pretty unique electrical infrastructure, provided by our electricity company.

We get the following
127 volts (yes 127 volts) single phase (blue and brown wires)
220 volts split phase (two brown wires)
Most of us only use 220 volts, since we receive 50hz (on both 127v and 220v).

In my current setup I have two MPP-Solar inverters with seperate Victron MPPT's.

The setup works perfectly fine. If there is enough solar and battery-power available the inverter puts out singe phase 230 volts and if the battery is under a certain level the inverter switches to grid and the house is powered via the 2 phase 220v, as supplied by the electricity company. All good so far.

I am considering to replace my current inverters with Victron inverters (the European models) and think that the power comming in from the grid might be an issue. The inverters deliver single phase 230v power to the house, but receive 220 split fase from the grid.
It is my understanding the Victron can be configured to supply some power from the grid to assist the inverter / or visa versa.
Since the output is single phase and the input is split phase, I think that combining that might cause a lot of smoke.

So I thought about the following two sollutions:

1) disconnect the Multiplusses totally from the grid
In this setup I can just connect the Multplusses to my current setup and the only thing I need is an additional Chargeverter
The Chargeverter will kick in at the moment the batteries are under 20% (or under a specific voltage), starts charging the batteries and the inverters just do their thing.

2) configure the Multiplus to not use grid feed-in and only charge
In this setup I don't need an additional charger and will connect the Multiplus to the grid and only use the Multiplus to charge the batteries, but not as a device that provides grid power in combination with battery power.

I know the first option will work for sure, and maybe that is the cleanest option, but if it is possible to go for option 2, I don't need an additional device that might break down and adds to the budget.

So preferably I go for the second option, but is that possible?

 

[TM48]

You say you have split phase at 50 hz. and 220v. If you ignore the neutral and only use the two brown wires it seems you could use it as input to the EU Victrons. It's called split phase but it's actually single phase split voltage. If everything is 50 hz it should work.

 

[Robbert]

You say you have split phase at 50 hz. and 220v. If you ignore the neutral and only use the two brown wires it seems you could use it as input to the EU Victrons. It's called split phase but it's actually single phase split voltage. If everything is 50 hz it should work.

Thank you. Actually that is how the system is being used at this moment. It is like the image as underneath.
In the current setup the system takes eighter 100% from the battery of 100% from the grid.
So at the moment the systems switches over battery/solar the Neutral becomes no neutral anymore and changes to L2. That works exactly as you mentioned.

But what happens at the moment that (let's say) 50% of the power comes from the grid and 50% comes from the battery?
Should that not cause an issue?

 

[TM48]

I'm no expert on Victrons. I'd suggest contacting Victron support and see what they advise.

 

[aussiesam]

Thank you. Actually that is how the system is being used at this moment. It is like the image as underneath. View attachment 255060
In the current setup the system takes eighter 100% from the battery of 100% from the grid.
So at the moment the systems switches over battery/solar the Neutral becomes no neutral anymore and changes to L2. That works exactly as you mentioned.

But what happens at the moment that (let's say) 50% of the power comes from the grid and 50% comes from the battery?
Should that not cause an issue?

I'm confused at how you managed to use a 230V Victron single phase inverter on a 3-phase grid.
Would be interested in an update. Please share the inverter model and if you were able to use it without a transformer to create 230V single phase, or if you are using 3 inverters.

 

[outboard1196]

I live on Bonaire, and we have a pretty unique electrical infrastructure, provided by our electricity company.

We get the following
127 volts (yes 127 volts) single phase (blue and brown wires)
220 volts split phase (two brown wires)
Most of us only use 220 volts, since we receive 50hz (on both 127v and 220v).

In my current setup I have two MPP-Solar inverters with seperate Victron MPPT's.

The setup works perfectly fine. If there is enough solar and battery-power available the inverter puts out singe phase 230 volts and if the battery is under a certain level the inverter switches to grid and the house is powered via the 2 phase 220v, as supplied by the electricity company. All good so far.

I am considering to replace my current inverters with Victron inverters (the European models) and think that the power comming in from the grid might be an issue. The inverters deliver single phase 230v power to the house, but receive 220 split fase from the grid.
It is my understanding the Victron can be configured to supply some power from the grid to assist the inverter / or visa versa.
Since the output is single phase and the input is split phase, I think that combining that might cause a lot of smoke.

So I thought about the following two sollutions:

1) disconnect the Multiplusses totally from the grid
In this setup I can just connect the Multplusses to my current setup and the only thing I need is an additional Chargeverter
The Chargeverter will kick in at the moment the batteries are under 20% (or under a specific voltage), starts charging the batteries and the inverters just do their thing.

2) configure the Multiplus to not use grid feed-in and only charge
In this setup I don't need an additional charger and will connect the Multiplus to the grid and only use the Multiplus to charge the batteries, but not as a device that provides grid power in combination with battery power.

I know the first option will work for sure, and maybe that is the cleanest option, but if it is possible to go for option 2, I don't need an additional device that might break down and adds to the budget.

So preferably I go for the second option, but is that possible?

I know certain models have a charge only switch.
You could install ve configure software and have a look around.

 

[Robbert]

I'm confused at how you managed to use a 230V Victron single phase inverter on a 3-phase grid.
Would be interested in an update. Please share the inverter model and if you were able to use it without a transformer to create 230V single phase, or if you are using 3 inverters.

It is used as an off-grid setup. So the the power coming in is like shore power or generator power.