Abnormal switching conditions also can result in the ferroresonance incidents. In the systems of Figures 10 to 12, the ferroresonance is encountered when one or two phases are disconnected from the source and the associated capacitances provide current paths. The system is supplied from the source connected phase(s). The capacitances are
most often associated with the cables, transmission lines, or the stray capacitances of the busbar or the transformer windings. Such ferroresonance cases often occur in the distribution networks. The operation of fuses in one or two phases, sequential opening/closing of the poles associated with the transformer, and single-phase auto-reclosing of the feeders can initiate the phenomena in a distribution network. However, in both transmission and distribution systems, also a stuck pole circuit breaker or a broken conductor provide the unbalanced energization conditions and cause this type of ferroresonance.