question

Good Question, OR rather "How can I continue to use the AC Coupled Fronius Primo/Symo to generate solar power when the selected Quattro input is a generator, or do I have to accept that it switches off which seems to fly in the face of the Fronius microgrid strategy and documentation about being able to use a fronius OFF-GRID with a generator

>>> Without a solution I will have to remove solar panels from the Fronius and put them on a Victron MPPT which means more Victron MPPT or bigger generators in every configuration <<<

This applies to both the ESS Assistant (Main Utility Power Connected) and the PV Inverter Assistant (no Utility Power - Off Grid), when the generator is started during the day the fronius switches off, system is configured for zero feed in and battery is in a low state of charge

The generator is required to charge the batteries, hence the loss of Fronius power is a problem, hence how do you set the Victron (float voltage / frequency shifting parameters) and Fronius to prevent the rejection of the Generator as an input source for the fronius . . .

I had exactly the same issue today. Not sure, though, if this issue needs to be tackled on the Quattro, or on the Fronius, on on the generator. In the end, the off-frequency (in my case, over-frequency) is there, it is not the Quattro's fault.

So I guess either
a) the Fronius should be set not to throttle (not an option, dangerous when Quattro is overloaded!?)
b) frequency would need to be actively balanced, not sure if the Quattro can do this at all, probably additional hardware needed
c) I could adjust the RPM of the generator with the calibration screw (in my case, slightly down from 52 Hz)

d) get a more expensive generator (no plans)

PowerAssist = Off, WeakAC = On, Accept wide input frequency range = On, UPS function = Off, AC input 1 = Generator, Grid code "other", no LOM detection (earlier we had issues with the generator being not recognized or shutting off on high loads - those settings solved the issues)

We are expecting power outages over the next months, wasting solar would unnecessarily increase the amount of fuel required by the generator. Thank you for ideas on how to improve the situation!