question

@assyntdavid

All ESS features fall away when grid is disconnected/blackout or AC ignore is used. So the two are not really compatible in their logic and function.

AC ignore overrides it all.

ESS being so highly variable/flexible (and in user interaction) makes it superior to the AC ignore as you have already noted.

What you can do is use the generator control from the GX and a flag assistant to control the primary relay to make grid disconnect easier/more flexible than the generator or general flag assistant. Requires a bit of control wiring between relays.

(Between the aux and the GX and an assisant to drive the primary relay based on the signal at the aux.)

Thanks @Alexandra. Many many months ago I asked the forum for suggestions on how best to fit and control an external relay to isolate the mains during scheduled time periods and I think you helped then. At the time I was unfamiliar with using the general flag or Cerbo relay but more importantly I had trouble sourcing a 230V 60A mains relay. (I don't know the size of the DNO fuse but it was meant to be 60A. Arguably I should fit a 100A relay just in case.) Plus I have limited space between the mains isolator and Multiplus in which to wire and fit the relay. So I stuck with manual switching of the grid.

Having recently unintentionally broken the 'rules' and set up ignore AC with ESS I have found that it DOES seem to work for my case. The ESS scheduled charging options all seem to work as normal, and I can't find anything that isn't working. So I'm left wondering why bother going to the expense and significant hassle of fitting an external relay, other than an irritating alarm that makes no sense? What am I missing?

Thanks @Alexandra for getting back, you are generous with your expertise and time. You have, via your comment, sorted the Alarm issue - hurrah! The Alarm problem lay with the 'Detect generator at AC input' option which was set to ON. This was already set to ON, and as electricity is electricity, I left it. However if you switch it OFF and try to reset it back to ON, you can't. An advisory appears saying that the AC input must be set to Generator first. Still slightly odd to me as the dashboard is still displaying the usual AC input data when it is connected.

I don't think my system puts any great demand on the ESS option. It is mainly a night storage system with some PV for summer. The house is low energy, batteries are oversized at 20kWh, historical PV is small at 1.4kW but sufficient for the house to be essentially off grid for 2-3 months on the summer. On the few occassions when batteries were full and we had spare PV I manually reconnected to the grid. When connected to the grid under simple ESS the Multiplus constantly 'hunts' around zero import/export. The small amounts of energy imported and exported during the day, combined with the increased self-use of energy by the Multiplus added signifcantly to the energy running costs of the system. But more than that my 10kW Multiplus 2 is in the middle of the house and very noisy, especially when connected to grid. The fan mod has improved matters, but watching tv or chatting in the lounge was unpleasant with the Multi on the other side of the wall. Even off grid in Inverter mode when running ~100W house loads it is significantly noisier than my other 5kW Multi in an off grid hut running ~50W loads - but tolerable. No idea why and not anticipated.

Thanks again

David

@Alexandra Interesting, I naively assumed that newer was better!! No regrets re Victron, the remote monitoring for our insolated hut is superb and offers all I need and more. But noise is important in homes, montorhomes, yachts, etc. It is surely something they must address going forward.

Happy Yuletide,

David