Siemens SIPROTEC 4 7UT6 Series Manual page 48

Functions
2.1 General
stabilising winding should be protected separately (e.g. with time overcurrent protection). During setting of
address 105 PROT. OBJECT = Autotransf., a stabilising winding can be included.
The current transformer X1 in
a restricted earth fault protection in this arrangement, you can feed the sum of the three currents measured at
M3 to an auxiliary 1-phase current input of the device. An example of a connection, where a measuring loca-
tion M3 serves as 3-phase measuring location for the current comparison and where simultaneously the total
current 3Ι0 of the transformer set is led to a 1-phase measuring location ΙX1 of the device, is available in the
annex.
[topologie-transformatorbank-def-1-strvergl-pro-pha-020603-st, 1, en_GB]
Figure 2-7
Sides:
S1 High voltage side of the auto-connected winding of the main protected object
S2 Low voltage side (tap) of the auto-connected winding of the main protected object
S3 Starpoint side of the auto-connected winding of the main protected object
Measuring locations 3-phase, assigned:
M1 Measuring location, assigned to the main protected object, side 1
M2 Measuring location, assigned to the main protected object, side 2
M3 Measuring location, assigned to the main protected object, side 3
Auxiliary measuring locations, 1-phase, assigned to the main object:
X1 Measuring location, assigned to the main protected object, side 1 and 2
Global Data for 1-Phase Busbar Protection
If the device is used as busbar protection, either as single-phase protection or as three-phase protection via
external summation transformers, set the number of feeders of the busbar in address 216 NUMBER OF ENDS.
The minimum number amounts to 3 ends (with less than that the operation of a 7UT6x would not make
sense).
In 7UT612, the maximum number of feeders is 7, in 7UT613 and 7UT633 it is 9, and in 7UT635 12.
48
Figure 2-7 is not required. In order to realise an earth overcurrent protection or
Topology of a transformer bank consisting of 3 single-phase auto-transformers, topology defi-
nitions for a current comparison protection for each phase
SIPROTEC 4, 7UT6x, Manual
C53000-G1176-C230-5, Edition 09.2016