For rated secondary currents please make sure that rated secondary transformer currents match with the rated
current of the corresponding current input of the device. Rated secondary currents of a device can be
matched. If summation transformers are used, the rated current at the outgoing side is usually 100 mA. For
rated secondary currents a value of 0.1 A is therefore set for all feeders.
Indication of the starpoint position of the current transformers determines the polarity of the current trans-
formers. Set for each feeder if the starpoint is looking towards the busbar or not. Figure 2-15 shows an
example of 3 feeders in which the transformer starpoint in feeder 1 and feeder 3 are looking towards the
busbar, unlike feeder 2.
If external interposed transformers are used, it is presumed that these are connected with correct polarity.
[anlagendaten-beispiel4-020904-st, 1, en_GB]
Figure 2-15 Position of the CT starpoints — example for phase L1 of a busbar with 3 feeders
The parameters for the individual feeders are:
Feeder 1
•
Address 561 STRPNT->BUS I1 = transformer starpoint versus busbar for feeder 1,
•
Address 562 IN-PRI CT I1 = rated primary transformer current for feeder 1,
•
Address 563 IN-SEC CT I1 = rated secondary transformer current for feeder 1.
Feeder 2
•
Address 571 STRPNT->BUS I2 = transformer starpoint versus busbar for feeder 2,
•
Address 572 IN-PRI CT I2 = rated primary transformer current for feeder 2,
•
Address 573 IN-SEC CT I2 = rated secondary transformer current for feeder 2.
Feeder 3
•
Address 581 STRPNT->BUS I3 = transformer starpoint versus busbar for feeder 3,
•
Address 582 IN-PRI CT I3 = rated primary transformer current for feeder 3,
•
Address 583 IN-SEC CT I3 = rated secondary transformer current for feeder 3.
Feeder 4
•
Address 591 STRPNT->BUS I4 = transformer starpoint versus busbar for feeder 4,
•
Address 592 IN-PRI CT I4 = rated primary transformer current for feeder 4,
•
Address 593 IN-SEC CT I4 = rated secondary transformer current for feeder 4.
Functions
2.1 General
64 SIPROTEC 4, 7UT6x, Manual
C53000-G1176-C230-5, Edition 09.2016