Hi Alarm:
If Hi-Alarm Energized or Hi Alarm De-Energized option is selected then relay will get energized or De-
energized, if selected parameter is greater than or equal to trip point.
Lo Alarm:
If Lo-Alarm Energized or Lo Alarm De-Energized option is selected then relay will get energized or De-
energized, if selected parameter is less than or equal to trip point.
#
Note:
For Lo-Alarm configuration, set the values of trip point & hysteresis such that %
trip point + % hysteresis should be less than 100% Value.
Example for Phase angle:
If trip point is set 70% then maximum applicable hysteresis is 42.8%. i.e Trip point 70%
(252 ) + Hysteresis 42.8% (107.8 ) = 359.8 If total value is greater than the 100% i.e.
°
°
°
360
° then relay will not release.
0
° (+1)
Relay De-energise
Relay Energise
0.4539(Trip point)
0.136(Hysterisis point)
180
° (-1)
90
° (0.00)
270
° (0.00)
0.4539
0.136
Note: This function will work irrespective of +/-
sign. It depends only on value.
Trip point can be set in the range as specified in
TABLE 3
of nominal value for Hi-Alarm & 10% to 100 % of
nominal value for Lo-Alarm.
Trip point:
Example for PF:
For Hi-Alarm Energized, if trip point is 70%
& hysterisis is 30%, then trip value =
0 . 7 x 9 0 ° = 6 3 ° . T r i p p i n g P F =
cos(63)=0.4539 & hysterisis = 0.3 x 0.4539
= 0.136.
Hence, the relay will energize above 0.4539 and de-
energize below 0.3179.
Hysteresis can be set in the range of 0.5% to 50 % of set trip point. If Hi-alarm Energized or Hi-alarm De-
energized is selected then relay will get De-energized or Energized respectively, if set parameter value is
less than Hysteresis. Similarly if Lo-alarm Energized or Lo-alarm De-Energized.
Note
: In case of lo alarm if trip point is set
greater than 80% then the maximum hysteresis can be set such
that the total Trip point+ Hysteresis(% of trip point value) will not exceed 120% of range.
For example :If trip point is set at 90%, then maximum 33.3% hysteresis should be set such that, [90 + 29.99
(33.3% of 90)] = 120.
Hysteresis:
55
