Victron Fronius AC coupling

DIY
, , ,
1

I am establishing my off grid system and need some advice please.

My system currently consists of -

A. 50 kw PV

B. 48 kva LIP storage

C. 3 x Multiplus 2 15kva inverters running as single phase

D. 2 x MPPT RS 450/200 controllers

I wish to connect up through AC coupling one or more Fronius primo 5 kw and 8 kw single phase grid tie inverter into my system.

I plan to installing another 50 kw of PV into my system in the short term.

The Fronius inverters are now available for $100 or less and 8 kw primo for $200 and 10kw Symo 3 phase for $300.

I have studied the Fronius/Victron webinars which teach that the Fronius inverter must be programmed to the inbuilt AC coupled settings.

  1. Is this resetting of the Fronius preprogrammed settings apply to all Fronius grid tie inverters?
  2. Can multiple Fronius inverters be AC coupled to a system such as I have?
  3. Can I use a Fronius 3 phase inverter and only connect it to a my single phase system?

I look forward to your advice, thank you.

2

Is your system 100% off grid or is there a grid connection?

  1. victron/fronius documentation
  2. Yes, make sure to follow the factor 1.0 rule
  3. not sure, but my guess would be only if you connect on the AC-in side and have a 3 phase grid connection.
3

Thank you

As stated at the outset we are off grid - no where near any grid :slight_smile:

My search did not disclose the link you provided - that is really helpful, thank you!

  1. victron/fronius documentation

Yes, the 1:1 rule means that I can’t have more than 45kva Fronius AC coupling input into my system.

that will be achieved through limiting the total of the Fronius inverter capacities.

I have to undertake more research to see how to parallel multiple Fronius inverters and whether, as with Victron inverters, they need to be identical models?

4

The 1:1 rule also relates to battery capacity, the victron system has to be able to absorb all energy from the fronius inverters when for example a load gets turned off.