I have an MP2 5kVA running as ESS.
Everything is OK - it's configured to minimise load taken from grid with feeding back excess from DC generation.
This seems to work well, except there's one issue I cannot understand.
I have configured a pair of assistants to close the AC Out 2 relay to heat my hot water when the SoC is above x% SoC and then shut down when SoC goes below y% SoC. This is working well.
I've now added a second pair of assistants to close and open the AC Out relay based on an auxiliary input trigger. This is driven from the Cerbo's "Relay 2" allowing me manual control in addition to the "automated" one linked to the SoC.
The problem is if I click close relay 2 in VRM, I can hear the Cerbo's relay click, then the MP2 AC Out 2 relay click a few seconds later (following the delay defined in the assistant) and the water starts heating. But power is taken from the grid, not from the batteries.
Of course, my SoC and battery power is more than sufficient to power the immersion heater load as it does this fine when driven by the SoC assistants. So why when using a auxiliary input set of relays does it draw from the grid? Is there an option to select? I thought having the system configured as ESS would mean it takes from battery (if it can) like it does when driven by the SoC assistants.
