Method and apparatus for determining wear and tear in machines

A method and apparatus for determining wear and tear in machines includes a method that determines a voltage draw and/or a current draw of a first subsystem of the machine during its operation, and wear and tear present in a second machine subsystem is determined based on the draw determined in the first subsystem. In one embodiment, a coal grinding machine includes a drive, a coal grinding mill driven by the drive, a device for determining an electrical draw of a current and/or voltage draw of the drive during operation, and a device for inferring wear and tear present in the coal grinding mill on the basis of voltage and/or current draw determined in the drive. The machine can include a device for inferring the quality or type of material (like coal) being processed in the mill based on the draw determined in the drive.