question

Try turning week AC on and see if that stops the gen from dropping in and out.

also try turning the country code to none as a test ( the ess will have to be removed) once you have it stable then turn things back on one at a time

It's not a repeated gen dropping in and out - I had that problem some time ago (with various grid codes tried) and got it fixed with the Other grid code.

It's one 30 second dropout on initial gen engagement, and then smooth running, followed by random dropouts of perhaps 30 seconds in duration after running on gen for 20 minutes or 2 hours.

When I manually bypass the ESS, and power my 20 A load directly from 20 kVA generator, there are no dropouts, ever.

Weak AC is to help weak generators as I understand, but my generator is not weak and does not need gradual current rampup: the gen can supply 80 A, and the ESS uses max 25 A from gen (current limited), while 40+ A is always used by directly generator powered equipment at the same time. None of these directly gen powered equipment experience noticeable power drops when the gen is engaged to the ESS system. The gen Voltage normally drops/increases between 229 and 235 V when en|disenaging the ESS, while the gen's current draw jumps by 20 A or more.

The major dropout is at random after the generator has been engaged for some time, with no drastic load, frequency, solar, etc. changes - see VRM graphs above (click on picture names to enlarge and see the detail), that shows warning, frequency, voltage, etc. at the time of one of these dropouts

Site: https://vrm.victronenergy.com/installation/42154/share/1713e1eb

Paul/Shane, thanks for the suggestions. The Quattro firmware is v496.
@Paul B
Save for the Weak AC, I have tried all your other suggestions before without success. I will try the Weak AC, depite the power factor warnings, but let me explain this:

1) My ESS supplies a critical sub-load of 4.3 kW. This can be perhaps go to 5 kW or more if the batteries are very flat, which I do not allow, as my gen (already running for some time) is engaged when the batteries reach 96% SOC. So the current limiting is on the amps used to charge the batteries, not on the amps powering the load, as the load does not change. The load drop happens even when the batteries are on absorption, i.e. request lowish charge amps.

2) When the Quattro drops the load, the monitoring shows that the Amps fall away and the gen voltage seen by the Quattro INcreases slightly, and then goes back to what it was before the load drop on re-engagement of the load. This is not consistent with a sudden load increase or other electrical change triggering the drop.

3) The rest of my electrical consumption system is the "grid" as the ESS sees it, but are still my loads, and carried by the same gen, and can reach maybe 65 A at most, but usually draws around 40 A. It is a laboratory, so furnaces and aircons (most are inverter types soft that starts|stops) start and stop, but there are several so this starting and stopping is usually staggered, so they change the load by perhaps 3 kW over a few minutes. But this happens all the time, and the load drop does not coincide with any specific load increase|decrease that I could find.

Regarding how I BYPASS THE ESS:

I have a manual (generator type isolator) swith by which I can electrically isolate the whole ESS system from the load and all AC. So then all my loads run as if the ESS, etc. does not exist. The solar panels and MPPTs work in isolation to charge the batteries, but cannot draw nor provide current through the Quattro as it's disconnected. So gen or utility power flows directly into the sub-load. The current draw on the gen is still similar to what it would it be if the ESS was engaged, save for a few amps used for battery charging. Now all loads draw perhaps 60 A and all run fine, but my critical load is now exposed to generator failure, etc. if that should happen.

The point of mentioning the isolation is to show that it is not the generator dropping the load or doing funny power things, as even a sensitive double conversion electronic UPS, downstream from the ESS, does not go into bypass or do funny things when running straight from gen, and syncs fine with the incoming AC.

@shaneyake
I do not want the Quattro to drop out at all. It could go into passthru for all I care, which would be fine as the load is not dropped; but it does not do that, it just drops all amps going in and out of the Quattro, and there are no errors logged. Surely if the Quattro experienced a shutdown or some other fault it would log an error or warning.