Protection of generators with earthed neutral against phase-to-earth insulation faults,
by the detection of a reduction of third harmonic residual voltage.
Protects the 10 to 20 % of the stator winding, neutral point end, not protected by the
ANSI 59N/64G1 function, neutral voltage displacement.
Characteristics

• choice of 2 tripping principles, according to the sensors used:

*fixed third harmonic undervoltage set point
*adaptive neutral and terminal third harmonic voltage comparator set point

• time-delayed definite time (DT) tripping.

Released for:Schneider Electric Nigeria