Sel 411L - Page 212

P.3.104
SEL-411L Relay Protection Manual Date Code 20151029
Protection Functions
CT Selection Procedure
Equation 3.41
Equation 3.42
Equation 3.43
Equation 3.44
Equation 3.45
Equation 3.46
Equation 3.47
Equation 3.48
Equation 3.49
Equation 3.50
Equation 3.51
Equation 3.52
Equation 3.53
IEC Application
Equation 3.54
Equation 3.55
1S
V
SC
3I
SC
---------------
110
331.5
----------------------- 2.016 prima== =
S
Z
1S
1XR
2
S
+
----------------------------------
2.016
138
2
+
---------------------- 0.053 primar===
X
1S
Z
1S
2
R
1S
2
– 2.016
2
0.053
2
– 2.015 primary== =
T
R
1S
R
1L
+ 0.053 0.089+ 0.142 prim== =
T
X
1S
X
1L
+ 2.015 0.726+ 2.741 prim== =
1T
R
1T
2
X
1T
2
– 0.142
2
2.741
2
– 2.745 primary== =
I
FP
V
S
3Z
1T

----------------------
110
32.745
--------------------------= 23.136 kA primary==
XR
3PH
X
1T
R
1T
---------
2.741
0.142
-------------= 19.303==
T
X
1S
Z
0
Z
1

S
X
1L
Z
0
Z
1

L
+ 0.320 primar==
T
R
1S
Z
0
Z
1

S
R
1L
Z
0
Z
1

L
+ 4.193 primar==
0T
R
0T
2
X
0T
2
– 0.320
2
4.193
2
– 4.205 primary== =
_PHG
3V
S

3ZZ
1T
Z
0T
+
---------------------------------------------------- 19.652 kA prim==
XR
PHG
2X
1T
X
0T
+
2R
1T
R
0T
+
----------------------------------- 16.018==
CT Ratio: 2400:1 A
Accuracy Class: 5P20
Rated VA: 30 VA
R
CT
:15 
ALF: 20
RLEAD: 0.25 
Relay Burden: 0.1 VA (1 A nominal)
SAT
VA
CT_RATED
I
NOM SEC
------------------------------- ALF 600 V===
Z
Relay
VA
RELAY
I
NOM SEC
2
------------------------
0.1 VA
1 A
2
------------------ 0.1 ===