I am trying to find a way to control a virtual switch (either Multi or Cerbo) only when the Multi is set to “charge only” mode.
I have looked into this in terms of Assistants but I see no flag assignments that can follow my requisite “inverter only”
Do I have to get involved with Node-Red to achieve such a facility?
Thanks
Do you want to stop charging at a certain SOC or what is the background?
I can’t quite follow the question.
Sorry, I explain better. I want to control an external device when the Multi is set to charge only mode
What kind of external device and what do you want to control it with ? via relay from the Multi or GX ?
I don’t mind from which but I would have thought the Multi switch would be the best candidate for that.
I need to control an external relay
Distinguishing between ‘inverter’ and ‘charger only’ mode is really difficult.
The virtual switch and the assistant actually only work for the entire device.
I’m still thinking about it … possibly via a diversion …
What do you want to control via the relay ?
I only use the grid from my building Nº 1 to charge the batteries of the off-grid building Nº 2 in rare cases, mostly in the winter.
I do not want the grounding conductor to be constantly connected between the Grid and the Microgrid hence the external relay.
But the ground conductor is connected via your 10mm mains cable anyway.
So why should it be cancelled?
Do you have such a special mains form?
It is not at the moment, I purposely created three grounding busbars, one for the PV, one for the line out and one for the line in so that I can bond them at my discretion.
The two buildings are 55 metres away from each other and the two grounding electrodes could be at a very high voltage differential (unless bonded together underground) in the event of lightning due to the earth’s voltage gradient.
That is not the only reason, the possibility of a grid neutral failure (outside my or another property), would allow any other building in the vicinity to use my neutral as a return path to the power station thus potentially also loading my microgrid ground conductor.
I could use the assistant to only connect AC1 in at a certain time but I would need to sense the incoming voltage and use that to activate the external device.
To do that I would have to access the internals of the Multi
Or could one create a flag showing when AC1 in internal relay is connected?
Multi Assistants can see ACIN prior to acceptance. Could be set to Accept at will and/or create a flag on an output relay. It can’t tell absolute time though, so may need an external signal to provide that - even a GX relay wired across could do that, so remote/automated control is possible…
Not sure I fully understand, would the flag become active only when AC IN is accepted?
In which case I would also need to create a flag to assign ACIn (Ignore/not) which responds to me selecting “charge only” and I cannot see that option.
Basically, I would like to use one action only, namely set to charge only in order to activate my external device as opposed to an additional input signal
You can set a sequence with time delays etc as you choose. I don’t really understand why the Charge Only thing. Personally I’d probably just switch ACOut2 to your remote system and have the Multi set to On state always.
As I stated earlier, I only use the grid from my building Nº 1 to charge the batteries of the off-grid building Nº 2 in rare cases, mostly in the winter.
I do not want the grounding conductor to be constantly connected between the Grid and the Microgrid hence the external relay.
My AC Out 2 is never in use and I don’t see how it would come into play in this instance.
ACOut2 is switchable. Consider wiring it to your remote application, then switch all at the same time…
Right, but I still need to use two actions . . or not?
Set up right, could be just turning on a GX relay, or automated for certain conditions or a set time. And your earth relay will follow. All in how you set up the Assistants, more than one of course.
Sorry, I still don’t see how any of that can be activated just by me simply setting the Multi to “charge only”
Don’t set it to Charge Only, I’ve said that. Why??
Simple, I do not want the ACIN to go to the AC out.
The Multi does not have an option for that, as soon as an ACIN is detected it automatically connects it to the AC out