Siemens SIPROTEC 5 Manual page 114

Power-System Data
5.4 Application and Setting Notes for Measuring Point Current 3-Phase (I-3ph)
Parameter: Rated secondary current
•
Default setting (_:8881:102) Rated secondary current = 1 A
With the Rated secondary current parameter, you set the current rated secondary current of the current
transformer.
Parameter: Current range
•
Default setting (_:8881:117) Current range = 100 x IR
The Current range parameter allows you to set the dynamic range for the current input. Please retain the
default setting for power-system protection applications. The current measuring range 1.6 x Irated applies for
the connection type 3-phase + IN-separate and the sensitive current input or for the measuring inputs.
Parameter: Neutr.point in dir.of ref.obj
•
Default setting (_:8881:116) Neutr.point in dir.of ref.obj = yes
The Neutr.point in dir.of ref.obj parameter is used to set the direction of the neutral point of the
current transformer (see following figure). Often, the neutral point of the current transformer is determined
by the direction of the protected object (for example, in the direction of the line, cable, transformer). For this
reason, the default setting of the parameter was defined as yes.
When switching the parameter, the direction of the phase currents and of the ground current IN or IN-sepa-
rate is rotated device-internally.
[dwpolstromwdl-251013, 1, en_US]
Figure 5-2
Parameter: Inverted phases
•
Default setting (_:8881:114) Inverted phases = none
The Inverted phases parameter is intended for special applications, for example, pumped-storage hydro-
power plants (see Chapter Phase-rotation reversal). This default setting may be retained for power-system
protection applications.
Parameter: Magnitude correction
•
Default setting (_:3841:103) Magnitude correction = 1.000
When using the Magnitude correction parameter, you adjust the magnitude (magnitude correction) for
the current input. This allows you to correct the tolerances of the primary current transformer phase-selec-
tively. The magnitude correction may be required for highly precise measurements. Use a comparison meas-
114
Polarity of Current Transformers
SIPROTEC 5, Fault Recorder, Manual
C53000-G5040-C018-5, Edition 11.2017