5-218 T60 Transformer Protection System GE Multilin
5.6 GROUPED ELEMENTS 5 SETTINGS
5
The undervoltage delay setting defines the family of curves shown below.
(EQ 5.44)
where: T = operating time
D = undervoltage delay setting (D = 0.00 operates instantaneously)
V = secondary voltage applied to the relay
V
pickup
= pickup level
Figure 5–116: INVERSE TIME UNDERVOLTAGE CURVES
At 0% of pickup, the operating time equals the
UNDERVOLTAGE DELAY setting.
T
D
1
V
V
pickup
------------------
–
--------------------------------- -
=
842788A1.CDR
% of voltage pickup
Time (seconds)