I have a Victron inverter charger 12V,3000w,120A running 230volts at 50hz. It has many high temp shut downs now whilst in charging mode. I have an external fan running to cool the unit but shut downs continue. There is no dust accumulation internally. Ventilation is reasonable. Ambient temperature is around 26-30degC. Is the unit failing? I am unable to send it to a repair facility as we are on a boat travelling the oceans. Any advice appreciated.