4.57
Date Code 20081022
Instruction Manual
SEL-787 Relay
Protection and Logic Functions
Voltage-Based Protection
Figure 4.34
Volts/Hertz Inverse-Time Characteristic, 24IC = 0.5
Figure 4.35
Volts/Hertz Inverse-Time Characteristic, 24IC = 1
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
t
p
24 ITD
3
V
sec
PTR
•
•
freq
-----------------------------------------
FNOM
VNOM 10
3
⋅
--------------------------------
•
24 IP
100%
--------------
--------------------------------------------------------------------------------
⎝
⎠
⎜
⎟
⎜
⎟
⎜
⎟
⎜
⎟
⎛
⎞
1
–
⎝
⎠
⎜
⎟
⎜
⎟
⎜
⎟
⎜
⎟
⎜
⎟
⎛
⎞
0.5
---------------------------------------------------------------------------------------------------------- onds
sec
=
100
0.01
0.1
1
10
100
1000
24C2T Operating Time
(seconds)
120
140
160
180
200
Volts/Hertz (%)
(24IP = 100%)
24ITD = 5.0
24ITD = 0.5
24ITD = 1.0
24ITD = 0.1
24ITD = 10.0
24ITD = 7.5
t
p
24 ITD
3
V
sec
PTR
•
•
freq
-----------------------------------------
FNOM
VNOM 10
3
⋅
--------------------------------
•
24 IP
100%
--------------
--------------------------------------------------------------------------------
⎝
⎠
⎜
⎟
⎜
⎟
⎜
⎟
⎜
⎟
⎛
⎞
1
–
⎝
⎠
⎜
⎟
⎜
⎟
⎜
⎟
⎜
⎟
⎜
⎟
⎛
⎞
1
------------------------------------------------------------------------------------------------------
onds
sec
=
Summary of Contents for SEL-787
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