ABB RET670 - Page 208

( )
( )
( ) ( )
2
0
2 2
Re
Re 1
Re Im
m
U
A X
K
A A
×
= +
+
é ù é ù
ë û ë û
EQUATION1287 V2 EN (Equation 117)
The imaginary component of the same factor is equal to equation 118.
( )
( )
( ) ( )
2
0
2 2
Im
Im
Re Im
m
U
A X
K
A A
×
=
+
é ù é ù
ë û ë û
EQUATION1288 V2 EN (Equation 118)
Ensure that the underreaching zones from both line ends will overlap a sufficient
amount (at least 10%) in the middle of the protected circuit.
Tapped line application
A
B
21 21
21
C
T
IC
IA
IB
-IB
en05000224_ansi.vsd
ANSI05000224 V1 EN
Figure 70: Example of tapped line with Auto transformer
Section 3 1MRK504116-UUS C
IED application
202
Application manual