After 6 months of smooth running, during this evening my solar system suddenly shut down so I went to the solar shed assuming a fuse had blown a so it was.
That was a 125A fuse in the Power In on a 100A battery, I immediately suspected a fault in the system so I changed the fuse and isolated all components reconnecting them one by one.
The battery was fully charged today by solar and only used down to 90%.
Every time I connect the Battery side of the MPPT and restart the system, the battery goes into protection mode and shuts the system down displaying a "Short Fault" even with the PV isolated and the input cables disconnected.
I have two 250/100 MPPTs however the second one was not connected to PV as yet but just to the system and visible on Cerbo, both of them are having the same effect
With the MPPTs isolated everything seems to work just fine and the inverter produces energy and delivers it to the building.
I tested the resistance of both the Battery side and PV side of both MPPTs and they are respectively 195.7kΩ an 950kΩ for the first one and the other 250/100 it seems to read similar values.
I cannot believe that both 6 months old chargers burned at the same time with no solar current at the time.
My peek PV voltage today never exceeded 221v as per image attached and as far as I know it never went near the limit of 250 before, in any case, as I said, the problem is the same with the second MPPT and that has never seen any PV input as yet as I was going to install 5 more panels next week.
Could the problem be in the distributor perhaps?
Any similar problem in our fraternity?
Thanks
