Siemens siprotec 7SA6, Manual

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Installation and Commissioning
8-9
7SA6 Manual
C53000-G1176-C156-2
8.1.2 Termination variants
Outline diagrams are shown in Appendix A, Section A.2. Connection examples for cur-
rent and voltage transformer circuits are provided in Appendix A, Section A.3. It must
be checked that the setting configuration of the
Power System Data 1 (P.System
Data 1)
corresponds with the connections to the device.
Currents
The Figures A-31 to A-39 show examples of the current transformer connection op-
tions.
For the normal connection according to Figure A-31 address
220
must be set to
I4
transformer
=
In prot. line
, and furthermore address
221
must be set to
I4/
Iph CT
=
1.000
.
For the connection as shown in Figures A-32 to A-35 the setting of address
220
must
also be
I4 transformer
=
In prot. line
. The factor
221 I4/Iph CT
may de-
viate from 1. For notes on how to calculate the factor, refer to Subsection 6.1.1 under
“Current Transformer Connection”. Remember that the 2-CT-connection according to
Figure A-34 or A-35 is permitted only in isolated or compensated systems.
In Figures A-36 and A-37, examples of the connection of the earth current of a parallel
line are shown (for parallel line compensation). In address
220 I4 transformer
the
setting option
In paral. line
must be set. The factor
221 I4/Iph CT
may deviate
from 1. For notes on how to calculate the factor, refer to Subsection 6.1.1.
In Figures A-38 and A-39, examples of the connection of the earth current of a source
transformer are shown. In address
220 I4 transformer
the setting option
IY
starpoint
must be set. Notes regarding the factor
221 I4/Iph CT
may again be
found in Subsection 6.1.1.
Voltages The Figures A-40 to A-47 show examples of the voltage transformer connection op-
tions.
For the normal connection as shown in Figure A-40 the 4th voltage measuring input
U
4
is not used. Correspondingly the address
210
must be set to
U4 transformer
=
Not connected
. The factor in address
211 Uph / Udelta
must, however, be set
to 1.73 (this factor is used internally for the conversion of measurement and fault re-
cording values).
Figure A-41 shows an example of the additional connection of an open-delta winding
of the set of voltage transformers. Address
210
must in this case be set to
U4 trans-
former
=
Udelta transf..
The factor in address
211 Uph / Udelta
is depend-
ent on the ratio of the open-delta winding. Notes may be referred to in Subsection
6.1.1 under “Voltage Transformer Connection”.
Also Figures A-42 to A-45 show examples of a connection of the open-delta winding
of a set of voltage transformers, in this cases, however, of a central set of transformers
at a busbar. The same considerations apply as stated in to the previous paragraph.
Remember that the 2-CT-connection according to Figure A-44 or A-45 is permitted
only for use on isolated or compensated systems.
Figures A-46 and A-47 show examples of the connection of a different voltage, in this
case the busbar voltage (e.g. for overvoltage protection). For overvoltage protection
address
210
must be set to
U4 transformer
=
Ux transformer
. The factor ad-
dress
215 U-line / Usync
is always equal to 1 unless the feederside VT and bus-
barside VT have a different transformation ratio. The factor in address
211 Uph /
Udelta
must be 1.73 (this factor is used internally for the conversion of measurement
and fault recording values).