Siemens SIPROTEC 4 7UT6 Series Manual page 63

Measuring Location 3
•
Address 531 STRPNT->OBJ M3 starpoint position of CT for measuring location M3,
•
Address 532 IN-PRI CT M3 prim. rated current of CTs for measuring location M3,
•
Address 533 IN-SEC CT M3 sec. nominal current CT for measuring location M3.
Measuring Location 4
•
Address 541 STRPNT->OBJ M4 starpoint position of CT for measuring location M4,
•
Address 542 IN-PRI CT M4 prim. rated current of CTs for measuring location M4,
•
Address 543 IN-SEC CT M4 sec. nominal current CT for measuring location M4.
Measuring Location 5
•
Address 551 STRPNT->OBJ M5 starpoint position of CT for measuring location M5,
•
Address 552 IN-PRI CT M5 prim. rated current of CTs for measuring location M5,
•
Address 553 IN-SEC CT M5 sec. nominal current CT for measuring location M5.
If the device is applied as transverse differential protection for generators or motors, special considerations
must be observed for the CT connections: In a healthy operational state all currents flow into the protected
object, i.e. in contrast to the other applications. Therefore you have to set a "wrong" polarity for one of the
current transformer sets. The part windings of the machine windings correspond to the "sides".
One example is illustrated in
towards the protected object, the opposite setting is to be selected for "side 2": STRPNT->OBJ M2 = NO.
[anlagendaten-beispiel3-020904-st, 1, en_GB]
Figure 2-14
Current Transformer Data for Single-phase Busbar Protection
The operational nominal currents of each feeder already have been set under margin heading "Object Data
with Busbars (1-phase Connection) with up to 7 or 9 or 12 Feeders". All feeder currents are referred to these
nominal feeder currents. However, the rated currents of the current transformers may differ from the nominal
feeder currents. Therefore, the device must be informed about the primary nominal currents of the current
transformers, too. In
If rated currents have already been matched by external equipment (e.g. by matching transformers), the rated
current value, used as a base value for the calculation of the external matching transformers, is to be indicated
uniform. Normally, it is the rated operational current. The same applies if external summation transformers
are used.
Indicate the rated primary transformer current for each feeder. The interrogation only applies to data of the
number of feeders determined during the configuration according to Section
margin heading "Global Data for 1-phase Busbar Protection" (address 216 NUMBER OF ENDS).
SIPROTEC 4, 7UT6x, Manual
C53000-G1176-C230-5, Edition 09.2016
Figure 2-14. Although the starpoints of both current transformer sets are looking
Current transformer starpoints in transverse differential protection - example
Figure 2-15 the rated CT currents are 1000 A (Feeder 1), and 500 A (Feeder 2 and 3).
Functions
2.1 General
2.1.4 Power System Data 1,
63