When my solar system is running i still see 130w being draw from the grid

[Aridom82]

Hi i finally got my system up and running. 3x Voltronic Max Axpert 8kw generating 3 phase power.
However when the system is running from solar/battery (sbu mode) i still see in the main panel watt meter a constant 0,13 kw being draw from the grid.
Are the inverters consuming this power? And if so, is there a way to reduce or fix this?
Thanks

 

[Aridom82]

I just checked and the inverters are the ones pulling 130 w from the grid while working. When i turn the leds off it lowers to 120w. It surprises me that the inverters get the power from the grid to work.
Is there any way to make the inverters get that idle power from the batteries/solar?

 

[RCinFLA]

Yes to first question, no to second question.

The power is usually being drawn from battery but AC charging will make up for the 120 watt overhead. Same applies when PV power is available but it may stop AC charging and rely solely on PV input to recharge battery. If PV sourcing drops below 120 watt the battery makes up of the overhead difference resulting in a net battery discharge draw.

60 to 80 watts idle overhead is normal for HF inverters. When PV SCC is running it adds 5-10 watts more overhead.

 

[Aridom82]

Yes to first question, no to second question.

The power is usually being drawn from battery but AC charging will make up for the 120 watt overhead. Same applies when PV power is available but it may stop AC charging and rely solely on PV input to recharge battery. If PV sourcing drops below 120 watt the battery makes up of the overhead difference resulting in a net battery discharge draw.

60 to 80 watts idle overhead is normal for HF inverters. When PV SCC is running it adds 5-10 watts more overhead.

I am sorry i am a bit confused. I have setup my inverters to only charge from solar, never to AC charge (setting 16 to OSO). Yet i still see that they draw 120 watts from the utility grid.
I dont understand why the inverters dont get this power from battery or solar, what am i missing?

 

[wattmatters]

I dont understand why the inverters dont get this power from battery or solar, what am i missing?

Annoying isn't it? I have a rebranded inverter of the same model.

The only way to stop it is to disconnect the grid input. But a 3-phase controllable contactor rated for 8 kW is probably not cheap.

 

[Aridom82]

Annoying isn't it? I have a rebranded inverter of the same model.

The only way to stop it is to disconnect the grid input. But a 3-phase controllable contactor rated for 8 kW is probably not cheap.

The three phase parallel system does not work with the grid disconnected. It seems to require the grid input to establish the phase order, and only when it checks that the input phases are correct it starts generating output power with the same phase configuration.
If there is no way to make the inverters get that overhead 120w exclusively from solar/battery i will have to invent something to get it the way i want it

 

[SamDeleted]

@Aridom82

Can you just turn off the mains power in to your house all together?

 

[Aridom82]

@Aridom82

Can you just turn off the mains power in to your house all together?

No, as i said the three phase parallel configuration requires grid input to function. I will have to trick them somehow

 

[SamDeleted]

No, as i said the three phase parallel configuration requires grid input to function. I will have to trick them somehow

130w X 24 is 3kw a day , would cost about £1 in the UK

£30 a month , plus standing charge

You'd be looking at £80 a month just to have that running here , a little disappointing if you ask me !

 

[wattmatters]

The three phase parallel system does not work with the grid disconnected.

That seems rather suboptimal. What happens when you have a grid outage?

 

[SamDeleted]

No, as i said the three phase parallel configuration requires grid input to function. I will have to trick them somehow

Does your system ever export power at all ?


If not you could look at feeding that 130w from a separate little inverter , powered off a car battery, charged off your main system

 

[Aridom82]

Does your system ever export power at all ?


If not you could look at feeding that 130w from a separate little inverter , powered off a car battery, charged off your main system

Yes i am thinking something like this, i will have to trick it with 3 phase input from a separate small inverter

 

[Aridom82]

So i have an update on this one. I have observed that as long as there is a tiny bit of solar power, the inverters will get their 120w from solar, even when the batteries are not full.

So the trick i am thinking about is putting some kind of power supply powered by a separated battery, that will switch place with the mppt when the solar panels are not producing enough energy (at night) to sustain that 120w in total.
I have knowledge of microcontrollers and i have done some projects in the past so i think i can manage to do it.

Anyway i will be posting the results. If anybody knows a simpler way to do it please let me know. Thanks