The article considers inductive interference components. A description of the induced voltage electromagnetic component is described in detail. The technique of the calculated wire suspension height determining based on the actual magnetic field distribution is presented. The technique for the number of power line spans determining is provided. Dependences of the magnetic field induction vector on the distance along one power line’s span are obtained. Relationships of the magnetic field induction determining error depending on the number of adjacent spans are obtained. Recommendations for the number of spans determining, which must be taken into account when evaluating the magnetic component of the power line electromagnetic field are given.