Patent ID: 8401803

Claim:
A method for determining a remaining lifetime of an air-flow-producing, rotating electrical device of a power electronics appliance having a control unit, in which device-specific lifetime data that are dependent on ambient conditions and operation as specified by a manufacturer of said device are used, comprising: determining an ambient temperature of said device with said control unit; determining a rotational speed of said device with said control unit; and calculating said remaining lifetime of said device with said control unit solely on a basis of the ambient temperature of the device, the rotational speed of the device, and the device-specific lifetime data, which vary as a function of the ambient temperature and the rotational speed, as specified by the manufacturer of the device, the method further comprising: registering operation conditions of the device with the control unit, and forming a model on a basis of the operation conditions as a basis for the remaining lifetime calculation, using the model to calculate the lifetime with time intervals that are related to the lifetime and the operation conditions, and using values of the measurement data collected during said time intervals in the lifetime calculation.