Hi,
Apologies for my lack of technical detail, I am more an owner rather than installer, we have had a system installed on our dairy farm that consists of:
3 quattro 48/15000, 2 fronius eco 27kw, colour controller, MPPT 450/100, 40 AGM 12-200 batteries and about 90kw of panels (cant remember exactly but roughly 55kw to the fronius and 35 to the MPPT) Lynx - power in 1000, shunt 1000 & distributor 1000.
System was sold to us as an off grid solution (i.e. no more electric bill). It has been installed with a changeover switch so we are either on gird with the fronius feeding any load first OR off grid with fronius covering load and then quattro pulling from the battery.
The system doesn't seem to cope with a large load when off grid, once its pulling about 15kw from the batteries voltage soon drops and the system cuts out so we are daily switching between on and off grid. Which is not only time consuming but creating some issues with electrical equipment.
I had a read through here and get the impression it should be possible to run batteries and grid together i.e. load first covered by fronius, then batteries and then grid. Is this correct? I asked our installer and he wanted to keep us as we are and add more batteries and panels. Our grid connection is reliable and so makes more sense to me to use it rather than a generator.
Thank you in advance for any guidance you can provide.