Last week, while the house’s distribution box was getting upgraded to house an extra in-line currrent metering unit, my Easun 3.2 kW hybrid MPPT inverter stopped working.
At that moment, I did not have the time to check mit out, and I took the connected load over to the off-grid standby output of my home battery. That also works for now.
So- today I disconnected the Easun and put it on the table for a closer look.
The inverter’s functions are OK, except when I connect the grid to the 230V input. That trips the RCCB in the distribution box.
In my experience, this usually means that a voltage spike has triggered a final blow to a protection circuit. And indeed, upon close inspection the VDR between GND and Phase was blown and was reading around 400 Ohms. That will trigger an RCCB indeed!
The crack was hidden under the black heatshrink tube
I cut the VDR out and ordered me a couple of new ones, unfortunately they need to come from the other side of the world. But- without the defective VDR the Easun works perfect again!
Cheers!