I have a new 250/60-Tr SmartSolar MPPT. Does anyone know if it has the built-in short relay to protect against PV voltage short to battery voltage? I would love for Victron to confirm this. I am sure a lot of owners of Victron MPPT’s are nervous now! My system is installed at a remote cabin so I cannot be onsite regularly.
Thank you Paul,
You’re right about surge protectors. i didn’t know. Thank you for sharing.
I didn’t do anything new. I am still researching about limiting voltage on the battery side.
Sorry, I was away for a while.
IMHO, the voltage breaker should be between the battery terminals of the MPPT and the battery or the bus bar, whichever comes first. In my case, that would be the bus bar—basically right after the battery terminals of the MPPT.
The PV side already has a breaker, but there is no voltage breaker before the MPPT. Overvoltage can kill the MPPT, but not necessarily anything after the battery side. There is already a fuse for overcurrent protection.
The real danger is the panel voltage appearing on the battery side. Once it burns your electronics and causes a short, the current could potentially be the panel current with the panel voltage appearing on the battery side. It could be really dangerous.
I saw it with my own eyes. I caught it because of the sound and the smoke. I am glad we are all thinking about a solution together.
A battery protector will not protect against this. I looked into it. It mainly protects the batteries, especially against low voltage, and it is not very reliable or configurable for high voltage.
If I made a mistake, please let me know, because I am learning as well. I am just sharing my observations and ideas.
MPPT Battery Terminals —> High Voltage Circuit Breaker → Bus Bar → To the battery and other electronics
One of the possible causes of an MPP circuit failure could be a surge event on the PV side (a lightning strike or the transfer of induced lightning current to the PV wiring). This is particularly the case if the system was not installed professionally (no direct earthing of the PV module frames without (!!) a connection to the primary or secondary network). It is not always permissible or possible to connect the battery side to a potential (forcibly connecting PE to battery negative); instead, it may only be necessary to connect the metal structures on site to PE.
This is precisely why surge protection must be integrated into the generator connection box, in order to protect the controllers.