Siemens siprotec 7SA6, Manual

Page: 199 / 876

Functions
6-9
7SA6 Manual
C53000-G1176-C156-2
Address
215
:
U-line / Usync
= 100 V/ 110 V =
0.91
Figure 6-9 Busbar voltage, measured across a power transformer
•
Connection of the U
4
input to any other voltage signal U
X
, which may be processed
by the overvoltage protection function, refer to Appendix A, Figure A-46 or A-47:
Address
210
is then set:
U4 transformer
=
Ux transformer
.
It is assumed, that the Ux transformer ratio is equal to the phase voltage transform-
er ratio.
•
If the U
4
input is not required, the following setting is applied:
Address
210 U4 transformer
=
Not connected
.
Also in this case the factor
Uph / Udelta
(Address
211
, refer to the above) is of
importance, as it is utilised for the scaling of the measurement and disturbance re-
cording signals.
Current
Transformer
Connection The device contains four current measurement inputs, three of which are connected
to the set of current transformers. The fourth current measuring input
I
4
may be utilised
in various ways:
•
Connection of the I
4
input to the earth current in the starpoint of the set of current
transformers on the protected feeder (normal connection, refer to Appendix A, Fig-
ure A-31):
Address
220
is then set to:
I4 transformer
=
In prot. line
and
Address
221
to
I4/Iph CT
= 1 .
•
Connection of the I
4
input to a separate earth current transformer on the protected
feeder (e.g. a summation CT or window-type current transformer, refer to Appendix
A, e.g. Figures A-32 to A-35).
Address
220
is then set to:
I4 transformer
=
In prot. line
and
Address
221
is set to
I4/Iph CT
:
L1
L2
L3
U
L1
U
L2
U
L3
(any voltage)
U
E
U
sync
Feeder
Busbar
Yd5
220 kV
400 kV/220 kV
U4 transformer
=
Usync transf.
U-line / Usync
=
0,91
Usync connect
=
L1–L3
ϕ
Upp-Uline
=
210
°
220 kV/100 V
400 kV
110 V
400 kV