ABB REG316 4 Series - Definite Time NPS

REG 316*4 1MRB520049-Uen / Rev. F ABB Switzerland Ltd
3-105
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
I
2
=
1
/
3
(I
R
+ a
2
I
S
+ a I
T
).