FIELD: electricity.
SUBSTANCE: device contains a tool for detection difference between current zero sequence before ground fault and current zero sequence during ground fault; a tool for detection difference between voltage zero sequence before ground fault and voltage zero sequence during ground fault; a tool for detection of total conductivity of a neutral or a respective value based on the ratio of difference of current zero sequences and difference of voltage zero sequences; and tool for comparison of a certain total conductivity of a neutral or a respective value with the preset performance characteristic in order to define a point of phase-to-ground fault. At that the preset performance characteristic being represented in total conductivity plane defines a closed area so that the centre of the closed area is apart from the datum point of total conductivity plane in direction of negative reactive conductance and/or in direction of negative electrical conductance.
EFFECT: independence of performance characteristics from a type of the mains neutral.
13 cl, 6 dwg
