Inverse Time Overcurrent - ABB REG316 4 Series Operating Instructions Manual

REG 316*4 1MRB520049-Uen / Rev. F
3.5.6. Inverse time overcurrent (Current-Inv)
A. Application
Overcurrent function with time delay inversely proportional to the
current and definite minimum tripping time (IDMT).
B. Features
operating characteristics
·
British Standard 142:
c = 0.02 :
c = 1
c = 2
insensitive to DC component
·
insensitive to harmonics
·
single or three-phase measurement
·
detection of the highest phase value in the three-phase mode
·
wider setting range than specified in B.S. 142.
·
C. Inputs and outputs
I. C.t./v.t. inputs:
· current
II. Binary inputs:
· Blocking
III. Binary outputs:
· pick-up
· tripping
IV. Measurements:
· current amplitude.
(see Fig. 3.5.6.1)
normal inverse
: very inverse and long time earth fault
: extremely inverse.
ABB Switzerland Ltd
according to
3-79