Schweitzer Engineering Laboratories SEL-387E - Volts;Hertz Setting Reference Information

3-68 Protection Functions Date Code 20080110
SEL-387E Instruction Manual
Volts/Hertz Setting Reference Information
100
0.01
0.1
1
10
100
120 140 160 180 200
24C2T Operating Time
(seconds)
Volts/Hertz (%)
(24IP = 100%)
24ITD = 5.0
24ITD = 7.5
24ITD = 10.0
24ITD = 0.5
24ITD = 1.0
24ITD = 0.1
DWG: M300G147
5.0
3
sec
p
1
%100
IP24
10VNOM
NFREQ
•
freq
PTR•V•3
ITD24
t
⎟
⎟
⎟
⎟
⎟
⎟
⎟
⎠
⎞
⎜
⎜
⎜
⎜
⎜
⎜
⎜
⎝
⎛
−
⎟
⎟
⎠
⎞
⎜
⎜
⎝
⎛
⋅
= seconds
Figure 3.41: Volts/Hertz Inverse-Time Characteristic, 24IC = 0.5