Hoyt Electrical Instrument Works, Inc. Alpha 40A Plus, Руководство по эксплуатации

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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.
Example for PF:
For Hi-Alarm Energized, if trip point is 70% &
hysterisis is 30%, then trip value = 0.7x90
°=63°.
Tripping PF = cos(63)=0.4539 &
hysterisis=0.3x0.4539=0.136.
TABLE 3
of nominal value for Hi-Alarm & 10% to
100 % of nominal value for Lo-Alarm.
Trip point:
Hysteresis:
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.
Energizing Delay:
The energizing delay can be set in the range from
1 to 10 sec.
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
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
Hence, the relay will energize above 0.4539 and
de-energize below 0.136.
of trip point & hysteresis such that % trip point +
% hysteresis should be less than 100%.
De-Energizing Delay:
The De-energizing delay can be set in the range
from 1 to 10 sec.
Note: This function will work irrespective of
+/- sign. It depends only on value.
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