I have an ESS system with a 5kva multiplus 2, 16kwh of pylontech batteries + 6kw solar panels. The system regularly gives warning alarms, which I suspect may be grid related but would like to be able to confirm. Overloads occur when high load appliances start up, when there is high solar production(& use by 3kw solar diverter) and recently has also started happening when the inverter is charging the batteries (i.e. loads are on pass through) overnight. Base loads are typically 300-500w.
The cabling from the utility's meter to the Multi and from the multi to the consumer units has low resistance (less than 0.1ohm measured with a fluke multi-function tester) and there's no sign of heating of cables or bad connections on the batteries or elsewhere. I suspect a high impedance grid connection as we are on the end of a rural spur. I have noted the grid voltage drops considerably (from 230v+ down to 220v or less sometimes) when the multi is charging. My supplier/installer has just been ignoring my repeated requests for assistance. Is there any way to be be certain is is a grid related problem before I talk to the DNO?
