FIELD: electricity.
SUBSTANCE: protection device comprises current transformers of zero sequence on each cable and power relay. Herewith, windings of the zero sequence current transformers of different cables are connected oppositely, provided that at the parallel connection of these windings the current relay winding is connected parallel to the windings of any current transformer, and at the series connection it is connected in series with the windings of the both transformers.
EFFECT: providing the protection selectivity.
2 dwg
