A friend of mine is running off-grid 3x 48/15K Multiplus, and 2 of them are linked as Master / Slave. Lately the master is switching OFF due to temperature problem (which is almost impossible as we are at 10C and a light charge is applied to them, less than 3kW.) The battery banks consists of 2 arrays of 48V/1500A (2V/1500A Hoppecke - 3kA available). No power is produced by the PV arrays, as it is currently the night.
It has started having this behaviour today, and we have checked the installation. When the temperature LED becomes red, we can hear the fans running full speed, but the air blown outside is cold.
I am thinking either a migh be a problem with a temperature sensor, or a fan which is just "dead" and that will not blow air into one of the areas of the Multiplus. Not even sure if it could be a dust problem, or if we have to check both master and slave, even the issue is reported on the master.
Anyone has an idea / procedure to determine what is the cause ?
Thanks for your help.