Fundamental issues of electromagnetic interference influencing transport electrical equipment used for railway purposes were presented in this paper. Train call recorder is an example of such equipment and it is the focal point here. In its daily operation it is exposed to electromagnetic environment. That interference may originate from both intended and unintended (static and mobile) electromagnetic interference spanning across vast areas of railway activity. Hence the importance of uninterrupted and undisrupted functioning of train call recorders under conditions of electromagnetic environment present over areas of railway activity.