Definite Time Nps - ABB REG316 4 Series Operating Instructions Manual

REG 316*4 1MRB520049-Uen / Rev. F
3.5.9. Definite time NPS (NPS-DT)
A. Application
Protection of generators against excessive heating of the rotor
due to asymmetrical load.
B. Features
· definite time delay
· insensitive to DC component
· insensitive to harmonics
· three-phase measurement.
C. Inputs and outputs
I. Analogue inputs:
· current
II. Binary inputs:
· blocking
III. Binary outputs:
· pick-up
· tripping
IV. Measurements:
· proportion of negative-sequence current component
1 2
I = / (I + a I + a I
2 3 R S
ABB Switzerland Ltd
).
T
3-105