Long-time protection: The long-time protection function protects cables (phases and neutral) against overloads. This function is based on true rms measurements. Thermal memory: The thermal memory continuously accounts for the amount of heat in the cables, both before and after tripping, whatever the value of the current (presence of an overload or not). The thermal memory optimises the long-time protection function of the circuit breaker by taking into account the temperature rise in the cables. The thermal memory assumes a cable cooling time of approximately 15 minutes.