摘要：The purpose of this paper is to analyze influence of design data on a component (1 - 2s)·f_0 in stator currents of induction motors, mainly used for cage fault diagnosis. This paper shows that such an approach does not always lead to a correct outcome. The considerations are based on a "classical" model of induction motors extended to cage asymmetry by introducing cage asymmetry factors k_(as)and k_a. It has been found that in order to estimate the level of the component (1 - 2s)·f_0, it is enough to know the pole-pair number "p" and the number of rotor slots "N". The main objective of the paper is to provide engineers with simple qualitative prediction of effects due to cage faults for various motors when information on design data is very limited.